Electrical Regulations and Standards 29 CFR 1926 Subpart K, Subpart V, 29 CFR 1910 Subpart R

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Electrical Regulations and Standards 29 CFR 1926 Subpart K, Subpart V, 29 CFR 1910 Subpart R, Subpart S, 1910.137 and 1910.147

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Subpart K – Electrical Subpart K –  ElectricalEl ect r i cal

§1926.400  Introduction This subpart addresses electrical safety requirements that are necessary for the practical safeguarding of employees involved in construction work and is divided into four major divisions and applicable definitions as follows: (a) Installation safety requirements. Installation safety requirements are contained in §§1926.402 through 1926.408. Included in this category are electric equipment and installations used to provide electric power and light on jobsites. [§1926.400(a)] (b)  Safety-related work practices. Safety-related work practices are contained in §§1926.416 and 1926.417. In addition to covering the hazards arising from the use of electricity at jobsites, these regulations also cover the hazards arising from the accidental contact, direct or indirect, by employees with all energized lines, above or below ground, passing through or near the jobsite. [§1926.400(b)]

(c) Safety-related maintenance and environmental considerations.

Safety-related maintenance and environmental considerations are contained in §§1926.431 and 1926.432. [§1926.400(c)] (d) Safety requirements for special equipment. Safety requirements for special equipment are contained in §1926.441. [§1926.400(d)]

(e) Definitions. Definitions applicable to this subpart are contained in §1926.449. [§1926.400(e)]

§1926.401  [Reserved] INSTALLATION SAFETY REQUIREMENTS §1926.402  Applicability (a)  Covered. Sections 1926.402 through 1926.408 contain installation safety requirements for electrical equipment and installations used to provide electric power and light at the jobsite. These sections apply to installations, both temporary and permanent, used on the jobsite; but these sections do not apply to existing permanent installations that were in place before the construction activity commenced. [§1926.402(a)] Note: If the electrical installation is made in accordance with the National Electrical Code ANSI/NFPA 70-1984, exclusive of Formal Interpretations and Tentative Interim Amendments, it will be deemed to be in compliance with §§1926.403 through 1926.408, except for §§1926.404(b)(1) and 1926.405(a)(2)(ii) (E), (F), (G), and (J).

(b) Not covered. Sections 1926.402 through 1926.408 do not cover installations used for the generation, transmission, and distribution of electric energy, including related communication, metering, control, and transformation installations. (However, these regulations do cover portable and vehicle-mounted generators used to provide power for equipment used at the jobsite.) See subpart V of this part for the construction of power distribution and transmission lines. [§1926.402(b)]

§1926.403  General requirements (a)  Approval. All electrical conductors and equipment shall be approved. [§1926.403(a)] (b) Examination, installation, and use of equipment [§1926.403(b)] (1)  Examination. The employer shall ensure that electrical equipment is free from recognized hazards that are likely to cause death or serious physical harm to employees. Safety of equipment shall be determined on the basis of the following considerations: [§1926.403(b)(1)] (i)  Suitability for installation and use in conformity with the provisions of this subpart. Suitability of equipment for an identified purpose may be evidenced by listing, labeling, or certification for that identified purpose. [§1926.403(b)(1)(i)] (ii) Mechanical strength and durability, including, for parts designed to enclose and protect other equipment, the adequacy of the protection thus provided. [§1926.403(b)(1)(ii)] (iii) Electrical insulation. [§1926.403(b)(1)(iii)] (iv) Heating effects under conditions of use. [§1926.403(b)(1)(iv)] (v) Arcing effects. [§1926.403(b)(1)(v)] (vi) Classification by type, size, voltage, current capacity, specific use. [§1926.403(b)(1)(vi)] (vii) Other factors which contribute to the practical safeguarding of employees using or likely to come in contact with the equipment. [§1926.403(b)(1)(vii)] (2)  Installation and use. Listed, labeled, or certified equipment shall be installed and used in accordance with instructions included in the listing, labeling, or certification. [§1926.403(b)(2)] (c) Interrupting rating. Equipment intended to break current shall have an interrupting rating at system voltage sufficient for the current that must be interrupted. [§1926.403(c)]

(d) Mounting and cooling of equipment [§1926.403(d)] (1) Mounting. Electric equipment shall be firmly secured to the surface on which it is mounted. Wooden plugs driven into holes in masonry, concrete, plaster, or similar materials shall not be used. [§1926.403(d)(1)] (2) Cooling. Electrical equipment which depends upon the natural circulation of air and convection principles for cooling of exposed surfaces shall be installed so that room air flow over such surfaces is not prevented by walls or by adjacent installed equipment. For equipment designed for floor mounting, clearance between top surfaces and adjacent surfaces shall be provided to dissipate rising warm air. Electrical equipment provided with ventilating openings shall be installed so that walls or other obstructions do not prevent the free circulation of air through the equipment. [§1926.403(d)(2)] (e)  Splices. Conductors shall be spliced or joined with splicing devices designed for the use or by brazing, welding, or soldering with a fusible metal or alloy. Soldered splices shall first be so spliced or joined as to be mechanically and electrically secure without solder and then soldered. All splices and joints and the free ends of conductors shall be covered with an insulation equivalent to that of the conductors or with an insulating device designed for the purpose. [§1926.403(e)] (f) Arcing parts. Parts of electric equipment which in ordinary operation produce arcs, sparks, flames, or molten metal shall be enclosed or separated and isolated from all combustible material. [§1926.403(f)]

(g)  Marking. Electrical equipment shall not be used unless the manufacturer's name, trademark, or other descriptive marking by which the organization responsible for the product may be identified is placed on the equipment and unless other markings are provided giving voltage, current, wattage, or other ratings as necessary. The marking shall be of sufficient durability to withstand the environment involved. [§1926.403(g)] (h)  Identification of disconnecting means and circuits. Each disconnecting means required by this subpart for motors and appliances shall be legibly marked to indicate its purpose, unless located and arranged so the purpose is evident. Each service, feeder, and branch circuit, at its disconnecting means or overcurrent device, shall be legibly marked to indicate its purpose, unless located and arranged so the purpose is evident. These markings shall be of sufficient durability to withstand the environment involved. [§1926.403(h)] (i) 600 Volts, nominal, or less. This paragraph applies to equipment operating at 600 volts, nominal, or less. [§1926.403(i)] (1) Working space about electric equipment. Sufficient access and working space shall be provided and maintained about all electric equipment to permit ready and safe operation and maintenance of such equipment. [§1926.403(i)(1)] (i) Working clearances. Except as required or permitted elsewhere in this subpart, the dimension of the working space in the direction of access to live parts operating at 600 volts or less and likely to require examination, adjustment, servicing, or maintenance while alive shall not be less than indicated in Table K-1. In addition to the dimensions shown in Table K-1, workspace shall not be less than 30 inches (762 mm) wide in front of the electric equipment. Distances shall be measured from the live parts if they are exposed, or from the enclosure front o r opening if the live parts are enclosed. Walls constructed of concrete, brick, or tile are considered to be grounded. Working space is not required in back of assemblies such as dead-front switchboards or motor control centers where there are no renewable or adjustable parts such as fuses or switches on the back and where all connections are accessible from locations other than the back. [§1926.403(i)(1)(i)]

Table K-1 — Working Clearances Nominal voltage to ground

Minimum clear distance for conditions1 (a)

(b)

(c)

Feet2

Feet2

Feet2

0-150

3

3

3

151-600

3

1 3 ⁄2

4

1Conditions (a), (b), and (c) are as follows:

(a) Exposed live parts on one side and no live or grounded parts on the other side of the working space, or exposed live parts on both sides effectively guarded by insulating material. Insulated wire or insulated busbars operating at not over 300 volts are not considered live parts. (b) Exposed live parts on one side and grounded parts on the other side. (c) Exposed live parts on both sides of the workspace [not guarded as provided in Condition (a)] with the operator between.

2Note: For International System of Units (SI): one foot=0.3048m.

1

K Electrical

GENERAL

§1926.403(i)

§1926.408

Subpart K – Electrical

§1926.408  Special systems (a) Systems over 600 volts, nominal. Paragraphs (a)(1) through (a)(4) of this section contain general requirements for all circuits and equipment operated at over 600 volts. [§1926.408(a)] (1) Wiring methods for fixed installations [§1926.408(a)(1)] (i) Above ground. Above- ground conductors shall be installed in rigid metal conduit, in intermediate metal conduit, in cable trays, in cablebus, in other suitable raceways, or as open runs of metal-clad cable designed for the use and purpose.

However, open runs of non-metallic-sheathed cable or of bare conductors or busbars may be installed in locations which are accessible only to qualified persons. Metallic shielding components, such as tapes, wires, or braids for conductors, shall be grounded. Open runs of insulated wires and cables having a bare lead sheath or a braided outer covering shall be supported in a manner designed to prevent physical damage to the braid or sheath. [§1926.408(a)(1)(i)] (ii) Installations emerging from the ground. Conductors emerging from the ground shall be enclosed in raceways. Raceways installed on poles shall be of rigid metal conduit, intermediate metal conduit, PVC schedule 80 or equivalent extending from the ground line up to a point 8 feet (2.44 m) above finished grade. Conductors entering a building shall be protected by an enclosure from the ground line to the point of entrance. Metallic enclosures shall be grounded. [§1926.408(a)(1)(ii)] (2) Interrupting and isolating devices. [§1926.408(a)(2)] (i) Circuit breakers. Circuit breakers located indoors shall consist of metal-enclosed or fire-resistant, cell-mounted units.

In locations accessible only to qualified personnel, open mounting of circuit breakers is permitted. A means of indicating the open and closed position of circuit breakers shall be provided. [§1926.408(a)(2)(i)] (ii) Fused cutouts. Fused cutouts installed in buildings or transformer vaults shall be of a type identified for the purpose.

They shall be readily accessible for fuse replacement. [§1926.408(a)(2)(ii)]

(iii) Equipment isolating means. A means shall be provided to completely isolate equipment for inspection and repairs.

Isolating means which are not designed to interrupt the load current of the circuit shall be either interlocked with a circuit interrupter or provided with a sign warning against opening them under load. [§1926.408(a)(2)(iii)] (3) Mobile and portable equipment. [§1926.408(a)(3)] (i) Power cable connections to mobile machines. A metallic enclosure shall be provided on the mobile machine for enclosing the terminals of the power cable. The enclosure shall include provisions for a solid connection for the ground wire(s) terminal to ground effectively the machine frame.

The method of cable termination used shall prevent any strain or pull on the cable from stressing the electrical connections. The enclosure shall have provision for locking so only authorized qualified persons may open it and shall be marked with a sign warning of the presence of energized parts. [§1926.408(a)(3)(i)] (ii) Guarding live parts. All energized switching and control parts shall be enclosed in effectively grounded metal cabinets or enclosures. Circuit breakers and protective equipment shall have the operating means projecting through the metal cabinet or enclosure so these units can be reset without locked doors being opened. Enclosures and metal cabinets shall be locked so that only authorized qualified persons have access and shall be marked with a sign warning of the presence of energized parts. Collector ring assemblies on revolving-type machines (shovels, draglines, etc.) shall be guarded. [§1926.408(a)(3)(ii)] (4) Tunnel installations. [§1926.408(a)(4)] (i) Application. The provisions of this paragraph apply to installation and use of high-voltage power distribution and utilization equipment which is associated with tunnels and which is portable and/or mobile, such as substations, trailers, cars, mobile shovels, draglines, hoists, drills, dredges, compressors, pumps, conveyors, and underground excavators. [§1926.408(a)(4)(i)]

(ii) Conductors. Conductors in tunnels shall be installed in one or more of the following: [§1926.408(a)(4)(ii)] [A] Metal conduit or other metal raceway, [§1926.408(a)(4)(ii)[A]] [B] Type MC cable, or [§1926.408(a)(4)(ii)[B]] [C] Other suitable multiconductor cable. [§1926.408(a)(4)(ii)[C]] Conductors shall also be so located or guarded as to protect them from physical damage. Multiconductor portable cable may supply mobile equipment. An equipment grounding conductor shall be run with circuit

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conductors inside the metal raceway or inside the multiconductor cable jacket. The equipment grounding conductor may be insulated or bare. (iii) Guarding live parts. Bare terminals of transformers, switches, motor controllers, and other equipment shall be enclosed to prevent accidental contact with energized parts. Enclosures for use in tunnels shall be drip-proof, weatherproof, or submersible as required by the environmental conditions. [§1926.408(a)(4)(iii)]

(iv) Disconnecting means. A disconnecting means that simultaneously opens all ungrounded conductors shall be installed at each transformer or motor location. [§1926.408(a)(4)(iv)] (v) Grounding and bonding. All nonenergized metal parts of electric equipment and metal raceways and cable sheaths shall be grounded and bonded to all metal pipes and rails at the portal and at intervals not exceeding 1000 feet (305 m) throughout the tunnel. [§1926.408(a)(4)(v)] (b) Class 1, Class 2, and Class 3 remote control, signaling, and powerlimited circuits [§1926.408(b)] (1) Classification. Class 1, Class 2, or Class 3 remote control, signaling, or power-limited circuits are characterized by their usage and electrical power limitation which differentiates them from light and power circuits. These circuits are classified in accordance with their respective voltage and power limitations as summarized in paragraphs (b)(1)(i) through (b)(1)(iii) of this section. [§1926.408(b)(1)] (i) Class 1 circuits. [§1926.408(b)(1)(i)] [A] A Class 1 power-limited circuit is supplied from a source having a rated output of not more than 30 volts and 1000 volt-amperes. [§1926.408(b)(1)(i)[A]] [B] A Class 1 remote control circuit or a Class 1 signaling circuit has a voltage which does not exceed 600 volts; however, the power output of the source need not be limited. [§1926.408(b)(1)(i)[B]] (ii) Class 2 and Class 3 circuits. [§1926.408(b)(1)(ii)] [A] Power for Class 2 and Class 3 circuits is limited either inherently (in which no overcurrent protection is required) or by a combination of a power source and overcurrent protection. [§1926.408(b)(1)(ii)[A]] [B] The maximum circuit voltage is 150 volts AC or DC for a Class 2 inherently limited power source, and 100 volts AC or DC for a Class 3 inherently limited power source. [§1926.408(b)(1)(ii)[B]]

[C] The maximum circuit voltage is 30 volts AC and 60 volts DC for a Class 2 power source limited by overcurrent protection, and 150 volts AC or DC for a Class 3 power source limited by overcurrent protection. [§1926.408(b)(1)(ii)[C]]

(iii) Application. The maximum circuit voltages in paragraphs (b)(1)(i) and (b)(1)(ii) of this section apply to sinusoidal AC or continuous DC power sources, and where wet contact occurrence is not likely. [§1926.408(b)(1)(iii)] (2) Marking. A Class 2 or Class 3 power supply unit shall not be used unless it is durably marked where plainly visible to indicate the class of supply and its electrical rating. [§1926.408(b)(2)] (c) Communications systems. [§1926.408(c)] (1) Scope. These provisions for communication systems apply to such systems as central-station-connected and non-centralstation-connected telephone circuits, radio receiving and transmitting equipment, and outside wiring for fire and burglar alarm, and similar central station systems. These installations need not comply with the provisions of §§1926.403 through 1926.408(b), except §1926.404(c)(1)(ii) and §1926.407. [§1926.408(c)(1)]

(2) Protective devices. [§1926.408(c)(2)] (i) Circuits exposed to power conductors. Communication circuits so located as to be exposed to accidental contact with light or power conductors operating at over 300 volts shall have each circuit so exposed provided with an approved protector. [§1926.408(c)(2)(i)] (ii) Antenna lead-ins. Each conductor of a lead-in from an outdoor antenna shall be provided with an antenna discharge unit or other means that will drain static charges from the antenna system. [§1926.408(c)(2)(ii)] (3) Conductor location. [§1926.408(c)(3)] (i) Outside of buildings. [§1926.408(c)(3)(i)] [A] Receiving distribution lead-in or aerial-drop cables attached to buildings and lead-in conductors to radio transmitters shall be so installed as to avoid the possibility of accidental contact with electric light or power conductors. [§1926.408(c)(3)(i)[A]]

Definitions applicable to this subpart

[§1926.408(c)(5)(iii)] [51 FR 25318, July 11, 1986, as amended at 61 FR 5510, Feb. 13, 1996]

§1926.416  General requirements (a)  Protection of employees. [§1926.416(a)] (1)  No employer shall permit an employee to work in such proximity to any part of an electric power circuit that the employee could contact the electric power circuit in the course of work, unless the employee is protected against electric shock by deenergizing the circuit and grounding it or by guarding it effectively by insulation or other means. [§1926.416(a)(1)] (2) In work areas where the exact location of underground electric powerlines is unknown, employees using jack-hammers, bars, or other hand tools which may contact a line shall be provided with insulated protective gloves. [§1926.416(a)(2)] (3) Before work is begun the employer shall ascertain by inquiry or direct observation, or by instruments, whether any part of an energized electric power circuit, exposed or concealed, is so located that the performance of the work may bring any person, tool, or machine into physical or electrical contact with the electric power circuit. The employer shall post and maintain proper warning signs where such a circuit exists. The employer shall advise employees of the location of such lines, the hazards involved, and the protective measures to be taken. [§1926.416(a)(3)]

(b) Passageways and open spaces. [§1926.416(b)] (1) Barriers or other means of guarding shall be provided to ensure that workspace for electrical equipment will not be used as a passageway during periods when energized parts of electrical equipment are exposed. [§1926.416(b)(1)] (2) Working spaces, walkways, and similar locations shall be kept clear of cords so as not to create a hazard to employees. [§1926.416(b)(2)]

(c) Load ratings. In existing installations, no changes in circuit protection shall be made to increase the load in excess of the load rating of the circuit wiring. [§1926.416(c)] (d) Fuses. When fuses are installed or removed with one or both terminals energized, special tools insulated for the voltage shall be used. [§1926.416(d)] (e) Cords and cables. [§1926.416(e)] (1)  Worn or frayed electric cords or cables shall not be used. [§1926.416(e)(1)]

(2) Extension cords shall not be fastened with staples, hung from nails, or suspended by wire. [§1926.416(e)(2)] [44 FR 8577, Feb. 9, 1979; 44 FR 20940, Apr. 6, 1979, as amended at 55 FR 42328, Oct. 18, 1990; 58 FR 35179, June 30, 1993; 61 FR 9251, Mar. 7, 1996; 61 FR 41738, Aug. 12, 1996]

§1926.417  Lockout and tagging of circuits (a)  Controls. Controls that are to be deactivated during the course of work on energized or deenergized equipment or circuits shall be tagged. [§1926.417(a)] (b)  Equipment and circuits. Equipment or circuits that are deenergized shall be rendered inoperative and shall have tags attached at all points where such equipment or circuits can be energized. [§1926.417(b)] (c) Tags. Tags shall be placed to identify plainly the equipment or circuits being worked on. [§1926.417(c)] [44 FR 8577, Feb. 9, 1979; 44 FR 20940, Apr. 6, 1979, as amended at 55 FR 42328, Oct. 18, 1990; 58 FR 35181, June 30, 1993; 61 FR 9251, Mar. 7, 1996; 61 FR 41739, Aug. 12, 1996]]

§1926.418 — 1926.430 [Reserved] §1926.431  Maintenance of equipment

The employer shall ensure that all wiring components and utilization equipment in hazardous locations are maintained in a dust-tight, dustignition-proof, or explosion-proof condition, as appropriate. There shall be no loose or missing screws, gaskets, threaded connections, seals, or other impairments to a tight condition.

§1926.432  Environmental deterioration of equipment

(a) Deteriorating agents — [§1926.432(a)] (1) Unless identified for use in the operating environment, no conductors or equipment shall be located: [§1926.432(a)(1)] (i) In damp or wet locations; [§1926.432(a)(1)(i)] (ii) Where exposed to gases, fumes, vapors, liquids, or other agents having a deteriorating effect on the conductors or equipment; or [§1926.432(a)(1)(ii)] (iii) Where exposed to excessive temperatures. [§1926.432(a)(1)(iii)] (2) Control equipment, utilization equipment, and busways approved for use in dry locations only shall be protected against damage from the weather during building construction. [§1926.432(a)(2)] (b) Protection against corrosion. Metal raceways, cable armor, boxes, cable sheathing, cabinets, elbows, couplings, fittings, supports, and support hardware shall be of materials appropriate for the environment in which they are to be installed. [§1926.432(b)]

§1926.433 — 1926.440 [Reserved] §1926.441  Batteries and battery charging

Bat t er i es and bat t er y char gi ng

(a) General requirements — [§1926.441(a)] (1) Batteries of the unsealed type shall be located in enclosures with outside vents or in well ventilated rooms and shall be arranged so as to prevent the escape of fumes, gases, or electrolyte spray into other areas. [§1926.441(a)(1)] (2) Ventilation shall be provided to ensure diffusion of the gases from the battery and to prevent the accumulation of an explosive mixture. [§1926.441(a)(2)] (3) Racks and trays shall be substantial and shall be treated to make them resistant to the electrolyte. [§1926.441(a)(3)] (4) Floors shall be of acid resistant construction unless protected from acid accumulations. [§1926.441(a)(4)] (5) Face shields, aprons, and rubber gloves shall be provided for workers handling acids or batteries. [§1926.441(a)(5)] (6) Facilities for quick drenching of the eyes and body shall be provided within 25 feet (7.62 m) of battery handling areas. [§1926.441(a)(6)]

(7) Facilities shall be provided for flushing and neutralizing spilled electrolyte and for fire protection. [§1926.441(a)(7)] (b) Charging — [§1926.441(b)] (1) Battery charging installations shall be located in areas designated for that purpose. [§1926.441(b)(1)] (2) Charging apparatus shall be protected from damage by trucks. [§1926.441(b)(2)]

(3) When batteries are being charged, the vent caps shall be kept in place to avoid electrolyte spray. Vent caps shall be maintained in functioning condition. [§1926.441(b)(3)]

§1926.442 — 1926.448 [Reserved] §1926.449  Definitions applicable to this subpart

D ef i ni t i onsappl i cabl et ot hi ssubpar t

The definitions given in this section apply to the terms used in subpart K. The definitions given here for “approved” and “qualified person” apply, instead of the definitions given in §1926.32, to the use of these terms in subpart K. Acceptable. An installation or equipment is acceptable to the Assistant Secretary of Labor, and approved within the meaning of this subpart K: (a) If it is accepted, or certified, or listed, or labeled, or otherwise determined to be safe by a qualified testing laboratory capable of determining the suitability of materials and equipment for installation and use in accordance with this standard; or (b) With respect to an installation or equipment of a kind which no qualified testing laboratory accepts, certifies, lists, labels, or determines to be safe, if it is inspected or tested by another Federal

11

K Electrical

[B] The clearance between lead-in conductors and any lightning protection conductors shall not be less than 6 feet (1.83 m). [§1926.408(c)(3)(i)[B]] (ii) On poles. Where practicable, communication conductors on poles shall be located below the light or power conductors.

Communications conductors shall not be attached to a crossarm that carries light or power conductors. [§1926.408(c)(3)(ii)] (iii) Inside of buildings. Indoor antennas, lead-ins, and other communication conductors attached as open conductors to the inside of buildings shall be located at least 2 inches (50.8 mm) from conductors of any light or power or Class 1 circuits unless a special and equally protective method of conductor separation is employed. [§1926.408(c)(3)(iii)] (4) Equipment location. Outdoor metal structures supporting antennas, as well as self-supporting antennas such as vertical rods or dipole structures, shall be located as far away from overhead conductors of electric light and power circuits of over 150 volts to ground as necessary to avoid the possibility of the antenna or structure falling into or making accidental contact with such circuits. [§1926.408(c)(4)] (5) Grounding. [§1926.408(c)(5)] (i) Lead-in conductors. If exposed to contact with electric light or power conductors, the metal sheath of aerial cables entering buildings shall be grounded or shall be interrupted close to the entrance to the building by an insulating joint or equivalent device. Where protective devices are used, they shall be grounded. [§1926.408(c)(5)(i)] (ii) Antenna structures. Masts and metal structures supporting antennas shall be permanently and effectively grounded without splice or connection in the grounding conductor. [§1926.408(c)(5)(ii)] (iii) Equipment enclosures. Transmitters shall be enclosed in a metal frame or grill or separated from the operating space by a barrier, all metallic parts of which are effectively connected to ground. All external metal handles and controls accessible to the operating personnel shall be effectively grounded. Unpowered equipment and enclosures shall be considered grounded where connected to an attached coaxial cable with an effectively grounded metallic shield.

§1926.449(b)

§1926.449

Subpart K – Electrical

agency, or by a State, municipal, or other local authority responsible for enforcing occupational safety provisions of the National Electrical Code, and found in compliance with those provisions; or (c) With respect to custom-made equipment or related installations which are designed, fabricated for, and intended for use by a particular customer, if it is determined to be safe for its intended use by its manufacturer on the basis of test data which the employer keeps and makes available for inspection to the Assistant Secretary and his authorized representatives.

Accepted. An installation is “accepted” if it has been inspected and found to be safe by a qualified testing laboratory.

Accessible. (As applied to wiring methods.) Capable of being removed or exposed without damaging the building structure or finish, or not permanently closed in by the structure or finish of the building.

(See “concealed” and “exposed.”)

Accessible. (As applied to equipment.) Admitting close approach; not guarded by locked doors, elevation, or other effective means.

(See“Readily accessible.”)

Ampacity. The current in amperes a conductor can carry continuously under the conditions of use without exceeding its temperature rating.

Appliances. Utilization equipment, generally other than industrial, normally built in standardized sizes or types, which is installed or connecetcd as a unit to perform one or more functions.

Approved. Acceptable to the authority enforcing this subpart. The authority enforcing this subpart is the Assistant Secretary of Labor for Occupational Safety and Health. The definition of “acceptable” indicates what is acceptable to the Assistant Secretary of Labor, and therefore approved within the meaning of this subpart.

Askarel. A generic term for a group of nonflammable synthetic chlorinated hydrocarbons used as electrical insulating media. Askarels of various compositional types are used. Under arcing conditions the gases produced, while consisting predominantly of noncombustible hydrogen chloride, can include varying amounts of combustible gases depending upon the askarel type.

Attachment plug (Plug cap)(Cap). A device which, by insertion in a receptacle, establishes connection between the conductors of the attached flexible cord and the conductors connected permanently to the receptacle.

Automatic. Self-acting, operating by its own mechanism when actuated by some impersonal influence, as for example, a change in current strength, pressure, temperature, or mechanical configuration.

Bare conductor. See “Conductor.”

Bonding. The permanent joining of metallic parts to form an electrically conductive path which will assure electrical continuity and the capacity to conduct safely any current likely to be imposed.

Bonding jumper. A reliable conductor to assure the required electrical conductivity between metal parts required to be electrically connected.

Branch circuit. The circuit conductors between the final overcurrent device protecting the circuit and the outlet(s).

Building. A structure which stands alone or which is cut off from adjoining structures by fire walls with all openings therein protected by approved fire doors.

Cabinet. An enclosure designed either for surface or flush mounting, and provided with a frame, mat, or trim in which a swinging door or doors are or may be hung.

Certified. Equipment is “certified” if it: (a) Has been tested and found by a qualified testing laboratory to meet applicable test standards or to be safe for use in a specified manner, and (b) Is of a kind whose production is periodically inspected by a qualified testing laboratory. Certified equipment must bear a label, tag, or other record of certification.

Circuit breaker. (a) (600 volts nominal, or less.) A device designed to open and close a circuit by nonautomatic means and to open the circuit automatically on a predetermined overcurrent without injury to itself when properly applied within its rating. (b) (Over 600 volts, nominal.) A switching device capable of making, carrying, and breaking currents under normal circuit conditions, and also making, carrying for a specified time, and breaking currents under specified abnormal circuit conditions, such as those of short circuit.

Class I locations. Class I locations are those in which flammable gases or vapors are or may be present in the air in quantities sufficient to produce explosive or ignitible mixtures. Class I locations include the following: (a) Class I, Division 1. A Class I, Division 1 location is a location: (1) In which ignitible concentrations of flammable gases or vapors may exist under normal operating conditions; or (2) In which ignitible concentrations of such gases or vapors may exist frequently because of repair or maintenance operations or because of leakage; or (3) In which breakdown or faulty operation of equipment or processes might release ignitible concentrations of flammable gases or vapors, and might also cause simultaneous failure of electric equipment.

Note: This classification usually includes locations where volatile flammable liquids or liquefied flammable gases are transferred from one container to another; interiors

12

of spray booths and areas in the vicinity of spraying and painting operations where volatile flammable solvents are used; locations containing open tanks or vats of volatile flammable liquids; drying rooms or compartments for the evaporation of flammable solvents; inadequately ventilated pump rooms for flammable gas or for volatile flammable liquids; and all other locations where ignitible concentrations of flammable vapors or gases are likely to occur in the course of normal operations.

(b) Class I, Division 2. A Class I, Division 2 location is a location: (1) In which volatile flammable liquids or flammable gases are handled, processed, or used, but in which the hazardous liquids, vapors, or gases will normally be confined within closed containers or closed systems from which they can escape only in case of accidental rupture or breakdown of such containers or systems, or in case of abnormal operation of equipment; or (2) In which ignitible concentrations of gases or vapors are normally prevented by positive mechanical ventilation, and which might become hazardous through failure or abnormal operations of the ventilating equipment; or (3) That is adjacent to a Class I, Division 1 location, and to which ignitible concentrations of gases or vapors might occasionally be communicated unless such communication is prevented by adequate positive-pressure ventilation from a source of clean air, and effective safeguards against ventilation failure are provided.

Note: This classification usually includes locations where volatile flammable liquids or flammable gases or vapors are used, but which would become hazardous only in case of an accident or of some unusual operating condition. The quantity of flammable material that might escape in case of accident, the adequacy of ventilating equipment, the total area involved, and the record of the industry or business with respect to explosions or fires are all factors that merit consideration in determining the classification and extent of each location.

Piping without valves, checks, meters, and similar devices would not ordinarily introduce a hazardous condition even though used for flammable liquids or gases. Locations used for the storage of flammable liquids or of liquefied or compressed gases in sealed containers would not normally be considered hazardous unless also subject to other hazardous conditions.

Electrical conduits and their associated enclosures separated from process fluids by a single seal or barrier are classed as a Division 2 location if the outside of the conduit and enclosures is a nonhazardous location.

Class II locations. Class II locations are those that are hazardous because of the presence of combustible dust. Class II locations include the following: (a) Class II, Division 1. A Class II, Division 1 location is a location: (1) In which combustible dust is or may be in suspension in the air under normal operating conditions, in quantities sufficient to produce explosive or ignitible mixtures; or (2) Where mechanical failure or abnormal operation of machinery or equipment might cause such explosive or ignitible mixtures to be produced, and might also provide a source of ignition through simultaneous failure of electric equipment, operation of protection devices, or from other causes, or (3) In which combustible dusts of an electrically conductive nature may be present.

Note: Combustible dusts which are electrically nonconductive include dusts produced in the handling and processing of grain and grain products, pulverized sugar and cocoa, dried egg and milk powders, pulverized spices, starch and pastes, potato and woodflour, oil meal from beans and seed, dried hay, and other organic materials which may produce combustible dusts when processed or handled. Dusts containing magnesium or aluminum are particularly hazardous and the use of extreme caution is necessary to avoid ignition and explosion.

(b) Class II, Division 2. A Class II, Division 2 location is a location in which: (1) Combustible dust will not normally be in suspension in the air in quantities sufficient to produce explosive or ignitible mixtures, and dust accumulations are normally insufficient to interfere with the normal operation of electrical equipment or other apparatus; or (2) Dust may be in suspension in the air as a result of infrequent malfunctioning of handling or processing equipment, and dust accumulations resulting therefrom may be ignitible by abnormal operation or failure of electrical equipment or other apparatus.

Note: This classification includes locations where dangerous concentrations of suspended dust would not be likely but where dust accumulations might form on or in the vicinity of electric equipment. These areas may contain equipment from which appreciable quantities of dust would escape under abnormal operating conditions or be adjacent to a Class II Division 1 location, as described above, into which an explosive or ignitible concentration of dust may be put into suspension under abnormal operating conditions.

Class III locations. Class III locations are those that are hazardous because of the presence of easily ignitible fibers or flyings but in which such fibers or flyings are not likely to be in suspension in the air in quantities sufficient to produce ignitible mixtures. Class 111 locations include the following: (a) Class III, Division 1. A Class III, Division 1 location is a location in which easily ignitible fibers or materials producing combustible flyings are handled, manufactured, or used.

Note: Easily ignitible fibers and flyings include rayon, cotton (including cotton linters and cotton waste), sisal or henequen, istle, jute, hemp, tow, cocoa fiber, oakum, baled waste kapok, Spanish moss, excelsior, sawdust, woodchips, and other material of similar nature.

(b) Class III, Division 2. A Class III, Division 2 location is a location in which easily ignitible fibers are stored or handled, except in process of manufacture.

Definitions applicable to this subpart

Grounded. Connected to earth or to some conducting body that serves in place of the earth.

Grounded, effectively (Over 600 volts, nominal.) Permanently connected to earth through a ground connection of sufficiently low impedance and having sufficient ampacity that ground fault current which may occur cannot build up to voltages dangerous to personnel.

Grounded conductor. A system or circuit conductor that is intentionally grounded.

Grounding conductor. A conductor used to connect equipment or the grounded circuit of a wiring system to a grounding electrode or electrodes.

Grounding conductor, equipment. The conductor used to connect the noncurrent-carrying metal parts of equipment, raceways, and other enclosures to the system grounded conductor and/or the grounding electrode conductor at the service equipment or at the source of a separately derived system.

Grounding electrode conductor. The conductor used to connect the grounding electrode to the equipment grounding conductor and/or to the grounded conductor of the circuit at the service equipment or at the source of a separately derived system.

Ground-fault circuit interrupter. A device for the protection of personnel that functions to deenergize a circuit or portion thereof within an established period of time when a current to ground exceeds some predetermined value that is less than that required to operate the overcurrent protective device of the supply circuit.

Guarded. Covered, shielded, fenced, enclosed, or otherwise protected by means of suitable covers, casings, barriers, rails, screens, mats, or platforms to remove the likelihood of approach to a point of danger or contact by persons or objects.

Hoistway. Any shaftway, hatchway, well hole, or other vertical opening or space in which an elevator or dumbwaiter is designed to operate.

Identified (conductors or terminals). Identified, as used in reference to a conductor or its terminal, means that such conductor or terminal can be recognized as grounded.

Identified (for the use). Recognized as suitable for the specific purpose, function, use, environment, application, etc. where described as a requirement in this standard. Suitability of equipment for a specific purpose, environment, or application is determined by a qualified testing laboratory where such identification includes labeling or listing.

Insulated conductor. See “Conductor.”

Interrupter switch. (Over 600 volts, nominal.) A switch capable of making, carrying, and interrupting specified currents.

Intrinsically safe equipment and associated wiring. Equipment and associated wiring in which any spark or thermal effect, produced either normally or in specified fault conditions, is incapable, under certain prescribed test conditions, of causing ignition of a mixture of flammable or combustible material in air in its most easily ignitible concentration.

Isolated. Not readily accessible to persons unless special means for access are used.

Isolated power system. A system comprising an isolating transformer or its equivalent, a line isolation monitor, and its ungrounded circuit conductors.

Labeled. Equipment or materials to which has been attached a label, symbol or other identifying mark of a qualified testing laboratory which indicates compliance with appropriate standards or performance in a specified manner.

Lighting outlet. An outlet intended for the direct connection of a lampholder, a lighting fixture, or a pendant cord terminating in a lampholder.

Listed. Equipment or materials included in a list published by a qualified testing laboratory whose listing states either that the equipment or material meets appropriate standards or has been tested and found suitable for use in a specified manner.

Location. (a) Damp location. Partially protected locations under canopies, marquees, roofed open porches, and like locations, and interior locations subject to moderate degrees of moisture, such as some basements. (b) Dry location. A location not normally subject to dampness or wetness. A location classified as dry may be temporarily subject to dampness or wetness, as in the case of a building under construction. (c) Wet location. Installations underground or in concrete slabs or masonry in direct contact with the earth, and locations subject to saturation with water or other liquids, such as locations exposed to weather and unprotected.

Mobile X-ray. X-ray equipment mounted on a permanent base with wheels and/or casters for moving while completely assembled.

Motor control center. An assembly of one or more enclosed sections having a common power bus and principally containing motor control units.

Outlet. A point on the wiring system at which current is taken to supply utilization equipment.

13

K Electrical

Collector ring. A collector ring is an assembly of slip rings for transferring electrical energy from a stationary to a rotating member.

Concealed. Rendered inaccessible by the structure or finish of the building. Wires in concealed raceways are considered concealed, even though they may become accessible by withdrawing them. [See “Accessible. (As applied to wiring methods.)”]

Conductor. (a) Bare. A conductor having no covering or electrical insulation whatsoever. (b) Covered. A conductor encased within material of composition or thickness that is not recognized as electrical insulation. (c) Insulated. A conductor encased within material of composition and thickness that is recognized as electrical insulation.

Controller. A device or group of devices that serves to govern, in some predetermined manner, the electric power delivered to the apparatus to which it is connected.

Covered conductor. See “Conductor.”

Cutout. (Over 600 volts, nominal.) An assembly of a fuse support with either a fuseholder, fuse carrier, or disconnecting blade. The fuseholder or fuse carrier may include a conducting element (fuse link), or may act as the disconnecting blade by the inclusion of a nonfusible member.

Cutout box. An enclosure designed for surface mounting and having swinging doors or covers secured directly to and telescoping with the walls of the box proper. (See “Cabinet.”)

Damp location. See “Location.”

Dead front. Without live parts exposed to a person on the operating side of the equipment.

Device. A unit of an electrical system which is intended to carry but not utilize electric energy.

Disconnecting means. A device, or group of devices, or other means by which the conductors of a circuit can be disconnected from their source of supply.

Disconnecting (or Isolating) switch. (Over 600 volts, nominal.) A mechanical switching device used for isolating a circuit or equipment from a source of power.

Dry location. See “Location.”

Enclosed. Surrounded by a case, housing, fence or walls which will prevent persons from accidentally contacting energized parts.

Enclosure. The case or housing of apparatus, or the fence or walls surrounding an installation to prevent personnel from accidentally contacting energized parts, or to protect the equipment from physical damage.

Equipment. A general term including material, fittings, devices, appliances, fixtures, apparatus, and the like, used as a part of, or in connection with, an electrical installation.

Equipment grounding conductor. See “Grounding conductor, equipment.”

Explosion-proof apparatus. Apparatus enclosed in a case that is capable of withstanding an explosion of a specified gas or vapor which may occur within it and of preventing the ignition of a specified gas or vapor surrounding the enclosure by sparks, flashes, or explosion of the gas or vapor within, and which operates at such an external temperature that it will not ignite a surrounding flammable atmosphere.

Exposed. (As applied to live parts.) Capable of being inadvertently touched or approached nearer than a safe distance by a person. It is applied to parts not suitably guarded, isolated, or insulated. (See “Accessible and “Concealed.”)

Exposed. (As applied to wiring methods.) On or attached to the surface or behind panels designed to allow access. [See “Accessible.

(As applied to wiring methods.)”]

Exposed. (For the purposes of §1926.408(d), Communications systems.) Where the circuit is in such a position that in case of failure of supports or insulation, contact with another circuit may result.

Externally operable. Capable of being operated without exposing the operator to contact with live parts.

Feeder. All circuit conductors between the service equipment, or the generator switchboard of an isolated plant, and the final branch-circuit overcurrent device.

Festoon lighting. A string of outdoor lights suspended between two points more than 15 feet (4.57 m) apart.

Fitting. An accessory such as a locknut, bushing, or other part of a wiring system that is intended primarily to perform a mechanical rather than an electrical function.

Fuse. (Over 600 volts, nominal.) An overcurrent protective device with a circuit opening fusible part that is heated and severed by the passage of overcurrent through it. A fuse comprises all the parts that form a unit capable of performing the prescribed functions. It may or may not be the complete device necessary to connect it into an electrical circuit.

Ground. A conducting connection, whether intentional or accidental, between an electrical circuit or equipment and the earth, or to some conducting body that serves in place of the earth.

§1926.449(c)

§1926.449

Subpart K – Electrical

Overcurrent. Any current in excess of the rated current of equipment or the ampacity of a conductor. It may result from overload (see definition), short circuit, or ground fault. A current in excess of rating may be accommodated by certain equipment and conductors for a given set of conditions. Hence the rules for overcurrent protection are specific for particular situations.

Overload. Operation of equipment in excess of normal, full load rating, or of a conductor in excess of rated ampacity which, when it persists for a sufficient length of time, would cause damage or dangerous overheating. A fault, such as a short circuit or ground fault, is not an overload. (See“Overcurrent.”)

Panelboard. A single panel or group of panel units designed for assembly in the form of a single panel; including buses, automatic overcurrent devices, and with or without switches for the control of light, heat, or power circuits; designed to be placed in a cabinet or cutout box placed in or against a wall or partition and accessible only from the front. (See “Switchboard.”)

Portable X-ray. X-ray equipment designed to be hand-carried.

Power fuse. (Over 600 volts, nominal.) See “Fuse.”

Power outlet. An enclosed assembly which may include receptacles, circuit breakers, fuseholders, fused switches, buses and watt-hour meter mounting means; intended to serve as a means for distributing power required to operate mobile or temporarily installed equipment.

Premises wiring system. That interior and exterior wiring, including power, lighting, control, and signal circuit wiring together with all of its associated hardware, fittings, and wiring devices, both permanently and temporarily installed, which extends from the load end of the service drop, or load end of the service lateral conductors to the outlet(s).

Such wiring does not include wiring internal to appliances, fixtures, motors, controllers, motor control centers, and similar equipment.

Qualified person. One familiar with the construction and operation of the equipment and the hazards involved.

Qualified testing laboratory. A properly equipped and staffed testing laboratory which has capabilities for and which provides the following services: (a) Experimental testing for safety of specified items of equipment and materials referred to in this standard to determine compliance with appropriate test standards or performance in a specified manner; (b) Inspecting the run of such items of equipment and materials at factories for product evaluation to assure compliance with the test standards; (c) Service-value determinations through field inspections to monitor the proper use of labels on products and with authority for recall of the label in the event a hazardous product is installed; (d) Employing a controlled procedure for identifying the listed and/ or labeled equipment or materials tested; and (e) Rendering creditable reports or findings that are objective and without bias of the tests and test methods employed.

Raceway. A channel designed expressly for holding wires, cables, or busbars, with additional functions as permitted in this subpart. Raceways may be of metal or insulating material, and the term includes rigid metal conduit, rigid nonmetallic conduit, intermediate metal conduit, liquidtight flexible metal conduit, flexible metallic tubing, flexible metal conduit, electrical metallic tubing, underfloor raceways, cellular concrete floor raceways, cellular metal floor raceways, surface raceways, wireways, and busways.

Readily accessible. Capable of being reached quickly for operation, renewal, or inspections, without requiring those to whom ready access is requisite to climb over or remove obstacles or to resort to portable ladders, chairs, etc. (See “Accessible.”)

Receptacle. A receptacle is a contact device installed at the outlet for the connection of a single attachment plug. A single receptacle is a single contact device with no other contact device on the same yoke. A multiple receptacle is a single device containing two or more receptacles.

Receptacle outlet. An outlet where one or more receptacles are installed.

Remote-control circuit. Any electric circuit that controls any other circuit through a relay or an equivalent device.

Sealable equipment. Equipment enclosed in a case or cabinet that is provided with a means of sealing or locking so that live parts cannot be made accessible without opening the enclosure. The equipment may or may not be operable without opening the enclosure.

Separately derived system. A premises wiring system whose power is derived from generator, transformer, or converter windings and has no direct electrical connection, including a solidly connected grounded circuit conductor, to supply conductors originating in another system.

Service. The conductors and equipment for delivering energy from the electricity supply system to the wiring system of the premises served.

Service conductors. The supply conductors that extend from the street main or from transformers to the service equipment of the premises supplied.

14

Service drop. The overhead service conductors from the last pole or other aerial support to and including the splices, if any, connecting to the service-entrance conductors at the building or other structure.

Service-entrance conductors, overhead system. The service conductors between the terminals of the service equipment and a point usually outside the building, clear of building walls, where joined by tap or splice to the service drop.

Service-entrance conductors, underground system. The service conductors between the terminals of the service equipment and the point of connection to the service lateral. Where service equipment is located outside the building walls, there may be no service-entrance conductors, or they may be entirely outside the building.

Service equipment. The necessary equipment, usually consisting of a circuit breaker or switch and fuses, and their accessories, located near the point of entrance of supply conductors to a building or other structure, or an otherwise defined area, and intended to constitute the main control and means of cutoff of the supply.

Service raceway. The raceway that encloses the service-entrance conductors.

Signaling circuit. Any electric circuit that energizes signaling equipment.

Switchboard. A large single panel, frame, or assembly of panels which have switches, buses, instruments, overcurrent and other protective devices mounted on the face or back or both. Switchboards are generally accessible from the rear as well as from the front and are not intended to be installed in cabinets. (See “Panelboard.”)

Switches. (a) General-use switch. A switch intended for use in general distribution and branch circuits. It is rated in amperes, and it is capable of interrupting its rated current at its rated voltage. (b) General-use snap switch. A form of general-use switch so constructed that it can be installed in flush device boxes or on outlet box covers, or otherwise used in conjunction with wiring systems recognized by this subpart. (c) Isolating switch. A switch intended for isolating an electric circuit from the source of power. It has no interrupting rating, and it is intended to be operated only after the circuit has been opened by some other means. (d) Motor-circuit switch. A switch, rated in horsepower, capable of interrupting the maximum operating overload current of a motor of the same horsepower rating as the switch at the rated voltage.

Switching devices. (Over 600 volts, nominal.) Devices designed to close and/or open one or more electric circuits. Included in this category are circuit breakers, cutouts, disconnecting (or isolating) switches, disconnecting means, and interrupter switches.

Transportable X-ray. X-ray equipment installed in a vehicle or that may readily be disassembled for transport in a vehicle.

Utilization equipment. Utilization equipment means equipment which utilizes electric energy for mechanical, chemical, heating, lighting, or similar useful purpose.

Utilization system. A utilization system is a system which provides electric power and light for employee workplaces, and includes the premises wiring system and utilization equipment.

Ventilated. Provided with a means to permit circulation of air sufficient to remove an excess of heat, fumes, or vapors.

Volatile flammable liquid. A flammable liquid having a flash point below 38 degrees C (100 degrees F) or whose temperature is above its flash point, or a Class II combustible liquid having a vapor pressure not exceeding 40 psia (276 kPa) at 38 °C (100 °F) whose temperature is above its flash point.

Voltage. (Of a circuit.) The greatest root-mean-square (effective) difference of potential between any two conductors of the circuit concerned.

Voltage, nominal. A nominal value assigned to a circuit or system for the purpose of conveniently designating its voltage class (as 120/240, 480Y/277, 600, etc.). The actual voltage at which a circuit operates can vary from the nominal within a range that permits satisfactory operation of equipment.

Voltage to ground. For grounded circuits, the voltage between the given conductor and that point or conductor of the circuit that is grounded; for ungrounded circuits, the greatest voltage between the given conductor and any other conductor of the circuit.

Watertight. So constructed that moisture will not enter the enclosure.

Weatherproof. So constructed or protected that exposure to the weather will not interfere with successful operation. Rainproof, raintight, or watertight equipment can fulfill the requirements for weatherproof where varying weather conditions other than wetness, such as snow, ice, dust, or temperature extremes, are not a factor.

Wet location. See “Location.”

Authority: Sections 6 and 8 of the Occupational Safety and Health Act of 1970 (29 U.S.C. 655 and 657); §107, Contract Work Hours and Safety Standards Act (40 U.S.C. 333); Secretary of Labor's Order No. 9- 83 (48 FR 35736) or 1-90 (55 FR 9033), as applicable; 29 CFR part 1911.

Wiring design and protection Table S-6 — Clearances From Ground Installations built before August 13, 2007 Distance

4.57 m (15.0 ft)

<600 V

<600 V

Conditions

Over areas, other than public streets, alleys, roads, and driveways, subject to truck traffic

Over public streets, alleys, roads, and driveways

Voltage to ground

Conditions

301 to 600 V

Over residential property and driveways. Over commercial areas subject to pedestrian traffic or to vehicular traffic other than truck traffic. (This category includes conditions covered under the 3.05-m (10.0-ft) category where the voltage exceeds 300 V.)

<600 V

Over public streets, alleys, roads, and driveways. Over commercial areas subject to truck traffic. Other land traversed by vehicles, including land used for cultivating or grazing and forests and orchards.

(3) Clearance from building openings. [§1910.304(c)(3)] (i) Service conductors installed as open conductors or multiconductor cable without an overall outer jacket shall have a clearance of not less than 914 mm (3.0 ft) from windows that are designed to be opened, doors, porches, balconies, ladders, stairs, fire escapes, and similar locations. However, conductors that run above the top level of a window may be less than 914 mm (3.0 ft) from the window. Vertical clearance of final spans above, or within 914 mm (3.0 ft) measured horizontally of, platforms, projections, or surfaces from which they might be reached shall be maintained in accordance with paragraph (c)(2) of this section. [§1910.304(c)(3)(i)]

(ii) Overhead service conductors may not be installed beneath openings through which materials may be moved, such as openings in farm and commercial buildings, and may not be installed where they will obstruct entrance to these building openings. [§1910.304(c)(3)(ii)] (4) Above roofs. Overhead spans of open conductors and open multiconductor cables shall have a vertical clearance of not less than 2.44 m (8.0 ft) above the roof surface. The vertical clearance above the roof level shall be maintained for a distance not less than 914 mm (3.0 ft) in all directions from the edge of the roof. [§1910.304(c)(4)] (i) The area above a roof surface subject to pedestrian or vehicular traffic shall have a vertical clearance from the roof surface in accordance with the clearance requirements of paragraph (c)(2) of this section. [§1910.304(c)(4)(i)] (ii) A reduction in clearance to 914 mm (3.0 ft) is permitted where the voltage between conductors does not exceed 300 and the roof has a slope of 102 mm (4 in.) in 305 mm (12 in.) or greater. [§1910.304(c)(4)(ii)] (iii) A reduction in clearance above only the overhanging portion of the roof to not less than 457 mm (18 in.) is permitted where the voltage between conductors does not exceed 300 if: [§1910.304(c)(4)(iii)] [A] The conductors do not pass above the roof overhang for a distance of more than 1.83 m (6.0 ft), 1.22 m (4.0 ft) horizontally, and [§1910.304(c)(4)(iii)[A]] [B] The conductors are terminated at a through-the-roof raceway or approved support. [§1910.304(c)(4)(iii)[B]] (iv) The requirement for maintaining a vertical clearance of 914 mm (3.0 ft) from the edge of the roof does not apply to the final conductor span, where the conductors are attached to the side of a building. [§1910.304(c)(4)(iv)] (d) Location of outdoor lamps. Lamps for outdoor lighting shall be located below all energized conductors, transformers, or other electric equipment, unless such equipment is controlled by a disconnecting means that can be locked in the open position, or unless adequate clearances or other safeguards are provided for relamping operations. [§1910.304(d)] (e) Services. [§1910.304(e)] (1) Disconnecting means. [§1910.304(e)(1)] (i) Means shall be provided to disconnect all conductors in a building or other structure from the service-entrance conductors. The service disconnecting means shall plainly indicate whether it is in the open or closed position and shall be installed at a readily accessible location nearest the point of entrance of the serviceentrance conductors. [§1910.304(e)(1)(i)]

(ii) Each service disconnecting means shall simultaneously disconnect all ungrounded conductors. [§1910.304(e)(1)(ii)] (iii) Each service disconnecting means shall be suitable for the prevailing conditions. [§1910.304(e)(1)(iii)] (2) Services over 600 volts, nominal. The following additional requirements apply to services over 600 volts, nominal. [§1910.304(e)(2)] (i) Service-entrance conductors installed as open wires shall be guarded to make them accessible only to qualified persons. [§1910.304(e)(2)(i)] (ii) Signs warning of high voltage shall be posted where unqualified employees might come in contact with live parts. [§1910.304(e)(2)(ii)]

(f)  Overcurrent protection. [§1910.304(f)] (1) 600 volts, nominal, or less. The following requirements apply to overcurrent protection of circuits rated 600 volts, nominal, or less. [§1910.304(f)(1)] (i) Conductors and equipment shall be protected from overcurrent in accordance with their ability to safely conduct current.

S

[§1910.304(f)(1)(i)]

(ii) Except for motor running overload protection, overcurrent devices may not interrupt the continuity of the grounded conductor unless all conductors of the circuit are opened simultaneously. [§1910.304(f)(1)(ii)] (iii) A disconnecting means shall be provided on the supply side of all fuses in circuits over 150 volts to ground and cartridge fuses in circuits of any voltage where accessible to other than qualified persons so that each individual circuit containing fuses can be independently disconnected from the source of power. However, a current-limiting device without a disconnecting means is permitted on the supply side of the service disconnecting means. In addition, a single disconnecting means is permitted on the supply side of more than one set of fuses as permitted by the exception in §1910.305(j)(4)(vi) for group operation of motors, and a single disconnecting means is permitted for fixed electric space-heating equipment. [§1910.304(f)(1)(iii)] (iv) Overcurrent devices shall be readily accessible to each employee or authorized building management personnel.

These overcurrent devices may not be located where they will be exposed to physical damage or in the vicinity of easily ignitable material. [§1910.304(f)(1)(iv)] (v) Fuses and circuit breakers shall be so located or shielded that employees will not be burned or otherwise injured by their operation. Handles or levers of circuit breakers, and similar parts that may move suddenly in such a way that persons in the vicinity are likely to be injured by being struck by them, shall be guarded or isolated. [§1910.304(f)(1)(v)] (vi) Circuit breakers shall clearly indicate whether they are in the open (off) or closed (on) position. [§1910.304(f)(1)(vi)] (vii) Where circuit breaker handles on switchboards are operated vertically rather than horizontally or rotationally, the up position of the handle shall be the closed (on) position. [§1910.304(f)(1)(vii)]

(viii) Circuit breakers used as switches in 120-volt and 277-volt, fluorescent lighting circuits shall be listed and marked "SWD.” [§1910.304(f)(1)(viii)]

(ix) A circuit breaker with a straight voltage rating, such as 240 V or 480 V, may only be installed in a circuit in which the nominal voltage between any two conductors does not exceed the circuit breaker's voltage rating. A two-pole circuit breaker may not be used for protecting a 3-phase, cornergrounded delta circuit unless the circuit breaker is marked 1 — 3 to indicate such suitability. A circuit breaker with a slash rating, such as 120/240 V or 480Y/277 V, may only be installed in a circuit where the nominal voltage of any conductor to ground does not exceed the lower of the two values of the circuit breaker's voltage rating and the nominal voltage between any two conductors does not exceed the higher value of the circuit breaker's voltage rating. [§1910.304(f)(1)(ix)] (2) Feeders and branch circuits over 600 volts, nominal. The following requirements apply to feeders and branch circuits energized at more than 600 volts, nominal: [§1910.304(f)(2)] (i) Feeder and branch-circuit conductors shall have overcurrent protection in each ungrounded conductor located at the point where the conductor receives its supply or at a location in the circuit determined under engineering supervision; [§1910.304(f)(2)(i)]

[A] Circuit breakers used for overcurrent protection of threephase circuits shall have a minimum of three overcurrent relays operated from three current transformers. On three-phase, three-wire circuits, an overcurrent relay in the residual circuit of the current transformers may replace one of the phase relays. An overcurrent relay,

21

Electrical

5.49 m (18.0 ft)

Maximum voltage

(continued) Installations built on or after August 13, 2007

§1910.304(f)

§1910.304

Subpart S – Electrical operated from a current transformer that links all phases of a three-phase, three-wire circuit, may replace the residual relay and one other phase-conductor current transformer. Where the neutral is not grounded on the load side of the circuit, the current transformer may link all three phase conductors and the grounded circuit conductor (neutral); and [§1910.304(f)(2)(i)[A]] [B] If fuses are used for overcurrent protection, a fuse shall be connected in series with each ungrounded conductor; [§1910.304(f)(2)(i)[B]]

(ii) Each protective device shall be capable of detecting and interrupting all values of current that can occur at its location in excess of its trip setting or melting point; [§1910.304(f)(2)(ii)] (iii) The operating time of the protective device, the available shortcircuit current, and the conductor used shall be coordinated to prevent damaging or dangerous temperatures in conductors or conductor insulation under short-circuit conditions; and [§1910.304(f)(2)(iii)]

(iv) The following additional requirements apply to feeders only: [§1910.304(f)(2)(iv)]

[A] The continuous ampere rating of a fuse may not exceed three times the ampacity of the conductors. The longtime trip element setting of a breaker or the minimum trip setting of an electronically actuated fuse may not exceed six times the ampacity of the conductor. For fire pumps, conductors may be protected for short circuit only; and [§1910.304(f)(2)(iv)[A]] [B] Conductors tapped to a feeder may be protected by the feeder overcurrent device where that overcurrent device also protects the tap conductor. [§1910.304(f)(2)(iv)[B]] (g) Grounding. Paragraphs (g)(1) through (g)(9) of this section contain grounding requirements for systems, circuits, and equipment. [§1910.304(g)]

(1) Systems to be grounded. Systems that supply premises wiring shall be grounded as follows: [§1910.304(g)(1)] (i) All 3-wire DC systems shall have their neutral conductor grounded; [§1910.304(g)(1)(i)] (ii) Two-wire DC systems operating at over 50 volts through 300 volts between conductors shall be grounded unless: [§1910.304(g)(1)(ii)]

[A] They supply only industrial equipment in limited areas and are equipped with a ground detector; [§1910.304(g)(1)(ii)[A]]

[B] They are rectifier-derived from an AC system complying with paragraphs (g)(1)(iii), (g)(1)(iv), and (g)(1)(v) of this section; or [§1910.304(g)(1)(ii)[B]] [C] They are fire-alarm circuits having a maximum current of 0.030 amperes; [§1910.304(g)(1)(ii)[C]] (iii) AC circuits of less than 50 volts shall be grounded if they are installed as overhead conductors outside of buildings or if they are supplied by transformers and the transformer primary supply system is ungrounded or exceeds 150 volts to ground; [§1910.304(g)(1)(iii)] (iv) AC systems of 50 volts to 1000 volts shall be grounded under any of the following conditions, unless exempted by paragraph (g)(1)(v) of this section: [§1910.304(g)(1)(iv)] [A] If the system can be so grounded that the maximum voltage to ground on the ungrounded conductors does not exceed 150 volts; [§1910.304(g)(1)(iv)[A]] [B] If the system is nominally rated three-phase, four-wire wye connected in which the neutral is used as a circuit conductor; [§1910.304(g)(1)(iv)[B]] [C] If the system is nominally rated three-phase, four-wire delta connected in which the midpoint of one phase is used as a circuit conductor; or [§1910.304(g)(1)(iv)[C]] [D] If a service conductor is uninsulated; [§1910.304(g)(1)(iv)[D]]

(v) AC systems of 50 volts to 1000 volts are not required to be grounded under any of the following conditions: [§1910.304(g)(1)(v)]

[A] If the system is used exclusively to supply industrial electric furnaces for melting, refining, tempering, and the like; [§1910.304(g)(1)(v)[A]]

[B] If the system is separately derived and is used exclusively for rectifiers supplying only adjustable speed industrial drives; [§1910.304(g)(1)(v)[B]] [C] If the system is separately derived and is supplied by a transformer that has a primary voltage rating less than 1000 volts, provided all of the following conditions are met: [§1910.304(g)(1)(v)[C]] [1] The system is used exclusively for control circuits; [§1910.304(g)(1)(v)[C][1]]

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[2] The conditions of maintenance and supervision ensure that only qualified persons will service the installation; [§1910.304(g)(1)(v)[C][2]] [3] Continuity of control power is required; and [§1910.304(g)(1)(v)[C][3]]

[4] Ground detectors are installed on the control system; [§1910.304(g)(1)(v)[C][4]]

[D] If the system is an isolated power system that supplies circuits in health care facilities; or [§1910.304(g)(1)(v)[D]] [E] If the system is a high-impedance grounded neutral system in which a grounding impedance, usually a resistor, limits the ground-fault current to a low value for 3-phase AC systems of 480 volts to 1000 volts provided all of the following conditions are met: [§1910.304(g)(1)(v)[E]]

[1] The conditions of maintenance and supervision ensure that only qualified persons will service the installation; [§1910.304(g)(1)(v)[E][1]] [2] Continuity of power is required; [§1910.304(g)(1)(v)[E][2]] [3] Ground detectors are installed on the system; and [§1910.304(g)(1)(v)[E][3]]

[4] Line-to-neutral loads are not served. [§1910.304(g)(1)(v)[E][4]]

(2) Conductor to be grounded. The conductor to be grounded for AC premises wiring systems required to be grounded by paragraph (g)(1) of this section shall be as follows: [§1910.304(g)(2)] (i) One conductor of a single-phase, two-wire system shall be grounded; [§1910.304(g)(2)(i)] (ii) The neutral conductor of a single-phase, three-wire system shall be grounded; [§1910.304(g)(2)(ii)] (iii) The common conductor of a multiphase system having one wire common to all phases shall be grounded; [§1910.304(g)(2)(iii)]

(iv) One phase conductor of a multiphase system where one phase is grounded shall be grounded; and [§1910.304(g)(2)(iv)] (v) The neutral conductor of a multiphase system in which one phase is used as a neutral conductor shall be grounded. [§1910.304(g)(2)(v)]

(3) Portable and vehicle-mounted generators. [§1910.304(g)(3)] (i) The frame of a portable generator need not be grounded and may serve as the grounding electrode for a system supplied by the generator under the following conditions: [§1910.304(g)(3)(i)]

[A] The generator supplies only equipment mounted on the generator or cord- and plug-connected equipment through receptacles mounted on the generator, or both; and [§1910.304(g)(3)(i)[A]]

[B] The noncurrent-carrying metal parts of equipment and the equipment grounding conductor terminals of the receptacles are bonded to the generator frame. [§1910.304(g)(3)(i)[B]]

(ii) The frame of a vehicle need not be grounded and may serve as the grounding electrode for a system supplied by a generator located on the vehicle under the following conditions: [§1910.304(g)(3)(ii)]

[A] The frame of the generator is bonded to the vehicle frame; [§1910.304(g)(3)(ii)[A]]

[B] The generator supplies only equipment located on the vehicle and cord- and plug-connected equipment through receptacles mounted on the vehicle; [§1910.304(g)(3)(ii)[B]] [C] The noncurrent-carrying metal parts of equipment and the equipment grounding conductor terminals of the receptacles are bonded to the generator frame; and [§1910.304(g)(3)(ii)[C]]

[D] The system complies with all other provisions of paragraph (g) of this section. [§1910.304(g)(3)(ii)[D]] (iii) A system conductor that is required to be grounded by the provisions of paragraph (g)(2) of this section shall be bonded to the generator frame where the generator is a component of a separately derived system. [§1910.304(g)(3)(iii)] (4) Grounding connections. [§1910.304(g)(4)] (i) For a grounded system, a grounding electrode conductor shall be used to connect both the equipment grounding conductor and the grounded circuit conductor to the grounding electrode. Both the equipment grounding conductor and the grounding electrode conductor shall be connected to the grounded circuit conductor on the supply side of the service disconnecting means or on the supply side of the system disconnecting means or overcurrent devices if the system is separately derived. [§1910.304(g)(4)(i)]

Wiring design and protection (ii) For an ungrounded service-supplied system, the equipment grounding conductor shall be connected to the grounding electrode conductor at the service equipment.

For an ungrounded separately derived system, the equipment grounding conductor shall be connected to the grounding electrode conductor at, or ahead of, the system disconnecting means or overcurrent devices. [§1910.304(g)(4)(ii)]

(iii) On extensions of existing branch circuits that do not have an equipment grounding conductor, grounding-type receptacles may be grounded to a grounded cold water pipe near the equipment if the extension was installed before August 13, 2007. When any element of this branch circuit is replaced, the entire branch circuit shall use an equipment grounding conductor that complies with all other provisions of paragraph (g) of this section. [§1910.304(g)(4)(iii)] (5) Grounding path. The path to ground from circuits, equipment, and enclosures shall be permanent, continuous, and effective. [§1910.304(g)(5)] [§1910.304(g)(6)]

(i) Metal cable trays, metal raceways, and metal enclosures for conductors shall be grounded, except that: [§1910.304(g)(6)(i)] [A] Metal enclosures such as sleeves that are used to protect cable assemblies from physical damage need not be grounded; and [§1910.304(g)(6)(i)[A]] [B] Metal enclosures for conductors added to existing installations of open wire, knob-and-tube wiring, and nonmetallicsheathed cable need not be grounded if all of the following conditions are met: [§1910.304(g)(6)(i)[B]] [1] Runs are less than 7.62 meters (25.0 ft); [§1910.304(g)(6)(i)[B][1]]

[2] Enclosures are free from probable contact with ground, grounded metal, metal laths, or other conductive materials; and [§1910.304(g)(6)(i)[B][2]] [3] Enclosures are guarded against employee contact. [§1910.304(g)(6)(i)[B][3]]

(ii) Metal enclosures for service equipment shall be grounded. [§1910.304(g)(6)(ii)]

(iii) Frames of electric ranges, wall-mounted ovens, countermounted cooking units, clothes dryers, and metal outlet or junction boxes that are part of the circuit for these appliances shall be grounded. [§1910.304(g)(6)(iii)] (iv) Exposed noncurrent-carrying metal parts of fixed equipment that may become energized shall be grounded under any of the following conditions: [§1910.304(g)(6)(iv)] [A] If within 2.44 m (8 ft) vertically or 1.52 m (5 ft) horizontally of ground or grounded metal objects and subject to employee contact; [§1910.304(g)(6)(iv)[A]] [B] If located in a wet or damp location and not isolated; [§1910.304(g)(6)(iv)[B]]

[C] If in electrical contact with metal; [§1910.304(g)(6)(iv)[C]] [D] If in a hazardous (classified) location; [§1910.304(g)(6)(iv)[D]] [E] If supplied by a metal-clad, metal-sheathed, or grounded metal raceway wiring method; or [§1910.304(g)(6)(iv)[E]] [F] If equipment operates with any terminal at over 150 volts to ground. [§1910.304(g)(6)(iv)[F]] (v) Notwithstanding the provisions of paragraph (g)(6)(iv) of this section, exposed noncurrent-carrying metal parts of the following types of fixed equipment need not be grounded: [§1910.304(g)(6)(v)]

[A] Enclosures for switches or circuit breakers used for other than service equipment and accessible to qualified persons only; [§1910.304(g)(6)(v)[A]] [B] Electrically heated appliances that are permanently and effectively insulated from ground; [§1910.304(g)(6)(v)[B]]

[C] Distribution apparatus, such as transformer and capacitor cases, mounted on wooden poles, at a height exceeding 2.44 m (8.0 ft) above ground or grade level; and [§1910.304(g)(6)(v)[C]] [D] Listed equipment protected by a system of double insulation, or its equivalent, and distinctively marked as such. [§1910.304(g)(6)(v)[D]] (vi) Exposed noncurrent-carrying metal parts of cord- and plug- connected equipment that may become energized shall be grounded under any of the following conditions: [§1910.304(g)(6)(vi)]

[A] If in hazardous (classified) locations (see §1910.307); [§1910.304(g)(6)(vi)[A]]

[B] If operated at over 150 volts to ground, except for guarded motors and metal frames of electrically heated appliances if the appliance frames are permanently and effectively insulated from ground; [§1910.304(g)(6)(vi)[B]] [C] If the equipment is of the following types: [§1910.304(g)(6)(vi)[C]]

[1] Refrigerators, freezers, and air conditioners; [§1910.304(g)(6)(vi)[C][1]]

[2] Clothes-washing, clothes-drying, and dishwashing machines, sump pumps, and electric aquarium equipment; [§1910.304(g)(6)(vi)[C][2]] [3] Hand-held motor-operated tools, stationary and fixed motor-operated tools, and light industrial motor-operated tools; [§1910.304(g)(6)(vi)[C][3]] [4] Motor-operated appliances of the following types: hedge clippers, lawn mowers, snow blowers, and wet scrubbers; [§1910.304(g)(6)(vi)[C][4]] [5] Cord- and plug-connected appliances used in damp or wet locations, or by employees standing on the ground or on metal floors or working inside of metal tanks or boilers; [§1910.304(g)(6)(vi)[C][5]] [6] Portable and mobile X-ray and associated equipment; [§1910.304(g)(6)(vi)[C][6]] [7] Tools likely to be used in wet and conductive locations; and [§1910.304(g)(6)(vi)[C][7]] [8] Portable hand lamps. [§1910.304(g)(6)(vi)[C][8]] (vii) Notwithstanding the provisions of paragraph (g)(6)(vi) of this section, the following equipment need not be grounded: [§1910.304(g)(6)(vii)]

[A] Tools likely to be used in wet and conductive locations if supplied through an isolating transformer with an ungrounded secondary of not over 50 volts; and [§1910.304(g)(6)(vii)[A]]

[B] Listed or labeled portable tools and appliances if protected by an approved system of double insulation, or its equivalent, and distinctively marked. [§1910.304(g)(6)(vii)[B]]

(7) Nonelectrical equipment. The metal parts of the following nonelectrical equipment shall be grounded: frames and tracks of electrically operated cranes and hoists; frames of nonelectrically driven elevator cars to which electric conductors are attached; hand-operated metal shifting ropes or cables of electric elevators; and metal partitions, grill work, and similar metal enclosures around equipment of over 750 volts between conductors. [§1910.304(g)(7)]

(8) Methods of grounding fixed equipment. [§1910.304(g)(8)] (i) Noncurrent-carrying metal parts of fixed equipment, if required to be grounded by this subpart, shall be grounded by an equipment grounding conductor that is contained within the same raceway, cable, or cord, or runs with or encloses the circuit conductors. For DC circuits only, the equipment grounding conductor may be run separately from the circuit conductors. [§1910.304(g)(8)(i)]

(ii) Electric equipment is considered to be effectively grounded if it is secured to, and in electrical contact with, a metal rack or structure that is provided for its support and the metal rack or structure is grounded by the method specified for the noncurrent-carrying metal parts of fixed equipment in paragraph (g)(8)(i) of this section. Metal car frames supported by metal hoisting cables attached to or running over metal sheaves or drums of grounded elevator machines are also considered to be effectively grounded. [§1910.304(g)(8)(ii)]

(iii) For installations made before April 16, 1981, electric equipment is also considered to be effectively grounded if it is secured to, and in metallic contact with, the grounded structural metal frame of a building. When any element of this branch circuit is replaced, the entire branch circuit shall use an equipment grounding conductor that complies with all other provisions of paragraph (g) of this section. [§1910.304(g)(8)(iii)] (9) Grounding of systems and circuits of 1000 volts and over (high voltage). If high voltage systems are grounded, they shall comply with all applicable provisions of paragraphs (g)(1) through (g)(8) of this section as supplemented and modified by the following requirements: [§1910.304(g)(9)] (i) Systems supplying portable or mobile high voltage equipment, other than substations installed on a temporary basis, shall comply with the following: [§1910.304(g)(9)(i)] [A] The system shall have its neutral grounded through an impedance. If a delta-connected high voltage system is used to supply the equipment, a system neutral shall be derived. [§1910.304(g)(9)(i)[A]]

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S Electrical

(6) Supports, enclosures, and equipment to be grounded.

§1910.304(g)

§1910.305

Subpart S – Electrical [B] Exposed noncurrent-carrying metal parts of portable and mobile equipment shall be connected by an equipment grounding conductor to the point at which the system neutral impedance is grounded. [§1910.304(g)(9)(i)[B]] [C] Ground-fault detection and relaying shall be provided to automatically deenergize any high voltage system component that has developed a ground fault. The continuity of the equipment grounding conductor shall be continuously monitored so as to deenergize automatically the high voltage feeder to the portable equipment upon loss of continuity of the equipment grounding conductor. [§1910.304(g)(9)(i)[C]]

[D] The grounding electrode to which the portable equipment system neutral impedance is connected shall be isolated from and separated in the ground by at least 6.1 m (20.0 ft) from any other system or equipment grounding electrode, and there shall be no direct connection between the grounding electrodes, such as buried pipe, fence, and so forth. [§1910.304(g)(9)(i)[D]] (ii) All noncurrent-carrying metal parts of portable equipment and fixed equipment, including their associated fences, housings, enclosures, and supporting structures, shall be grounded. However, equipment that is guarded by location and isolated from ground need not be grounded. Additionally, pole-mounted distribution apparatus at a height exceeding 2.44 m (8.0 ft) above ground or grade level need not be grounded. [§1910.304(g)(9)(ii)] [46 FR 4056, Jan. 16, 1981, as amended at 73 FR 64205, Oct. 29, 2008]

§1910.305  Wiring methods, components, and equipment for general useW iringm ethods,o cmponent,sandequipmentfo rg eneraluse (a)  Wiring methods. The provisions of this section do not apply to conductors that are an integral part of factory-assembled equipment. [§1910.305(a)]

(1) General requirements. [§1910.305(a)(1)] (i) Metal raceways, cable trays, cable armor, cable sheath, enclosures, frames, fittings, and other metal noncurrent-carrying parts that are to serve as grounding conductors, with or without the use of supplementary equipment grounding conductors, shall be effectively bonded where necessary to ensure electrical continuity and the capacity to conduct safely any fault current likely to be imposed on them. Any nonconductive paint, enamel, or similar coating shall be removed at threads, contact points, and contact surfaces or be connected by means of fittings designed so as to make such removal unnecessary. [§1910.305(a)(1)(i)] (ii) Where necessary for the reduction of electrical noise (electromagnetic interference) of the grounding circuit, an equipment enclosure supplied by a branch circuit may be isolated from a raceway containing circuits supplying only that equipment by one or more listed nonmetallic raceway fittings located at the point of attachment of the raceway to the equipment enclosure. The metal raceway shall be supplemented by an internal insulated equipment grounding conductor installed to ground the equipment enclosure. [§1910.305(a)(1)(ii)]

(iii) No wiring systems of any type may be installed in ducts used to transport dust, loose stock, or flammable vapors.

No wiring system of any type may be installed in any duct used for vapor removal or for ventilation of commercialtype cooking equipment, or in any shaft containing only such ducts. [§1910.305(a)(1)(iii)] (2)  Temporary wiring. Except as specifically modified in this paragraph, all other requirements of this subpart for permanent wiring shall also apply to temporary wiring installations. [§1910.305(a)(2)]

(i)  Temporary electrical power and lighting installations of 600 volts, nominal, or less may be used only as follows: [§1910.305(a)(2)(i)]

[A] During and for remodeling, maintenance, or repair of buildings, structures, or equipment, and similar activities; [§1910.305(a)(2)(i)[A]]

[B] For a period not to exceed 90 days for Christmas decorative lighting, carnivals, and similar purposes; or [§1910.305(a)(2)(i)[B]]

[C] For experimental or development work, and during emergencies. [§1910.305(a)(2)(i)[C]] (ii) Temporary wiring shall be removed immediately upon completion of the project or purpose for which the wiring was installed. [§1910.305(a)(2)(ii)] (iii) Temporary electrical installations of more than 600 volts may be used only during periods of tests, experiments, emergencies, or construction-like activities. [§1910.305(a)(2)(iii)]

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(iv) The following requirements apply to feeders: [§1910.305(a)(2)(iv)]

[A] Feeders shall originate in an approved distribution center. [§1910.305(a)(2)(iv)[A]]

[B] Conductors shall be run as multiconductor cord or cable assemblies. However, if installed as permitted in paragraph (a)(2)(i)(C) of this section, and if accessible only to qualified persons, feeders may be run as single insulated conductors. [§1910.305(a)(2)(iv)[B]] (v) The following requirements apply to branch circuits: [§1910.305(a)(2)(v)]

[A] Branch circuits shall originate in an approved power outlet or panelboard. [§1910.305(a)(2)(v)[A]] [B] Conductors shall be multiconductor cord or cable assemblies or open conductors. If run as open conductors, they shall be fastened at ceiling height every 3.05 m (10.0 ft). [§1910.305(a)(2)(v)[B]]

[C] No branch-circuit conductor may be laid on the floor. [§1910.305(a)(2)(v)[C]]

[D] Each branch circuit that supplies receptacles or fixed equipment shall contain a separate equipment grounding conductor if run as open conductors. [§1910.305(a)(2)(v)[D]]

(vi) Receptacles shall be of the grounding type. Unless installed in a continuous grounded metallic raceway or metallic covered cable, each branch circuit shall contain a separate equipment grounding conductor and all receptacles shall be electrically connected to the grounding conductor. [§1910.305(a)(2)(vi)]

(vii) No bare conductors nor earth returns may be used for the wiring of any temporary circuit. [§1910.305(a)(2)(vii)] (viii) Suitable disconnecting switches or plug connectors shall be installed to permit the disconnection of all ungrounded conductors of each temporary circuit. Multiwire branch circuits shall be provided with a means to disconnect simultaneously all ungrounded conductors at the power outlet or panelboard where the branch circuit originated. [§1910.305(a)(2)(viii)] Note to paragraph (a)(2)(viii) of this section. Circuit breakers with their handles connected by approved handle ties are considered a single disconnecting means for the purpose of this requirement.

(ix) All lamps for general illumination shall be protected from accidental contact or breakage by a suitable fixture or lampholder with a guard. Brass shell, paper-lined sockets, or other metal-cased sockets may not be used unless the shell is grounded. [§1910.305(a)(2)(ix)] (x) Flexible cords and cables shall be protected from accidental damage, as might be caused, for example, by sharp corners, projections, and doorways or other pinch points. [§1910.305(a)(2)(x)]

(xi) Cable assemblies and flexible cords and cables shall be supported in place at intervals that ensure that they will be protected from physical damage. Support shall be in the form of staples, cables ties, straps, or similar type fittings installed so as not to cause damage. [§1910.305(a)(2)(xi)] (3)  Cable trays. [§1910.305(a)(3)] (i) Only the following wiring methods may be installed in cable tray systems: armored cable; electrical metallic tubing; electrical nonmetallic tubing; fire alarm cables; flexible metal conduit; flexible metallic tubing; instrumentation tray cable; intermediate metal conduit; liquidtight flexible metal conduit; liquidtight flexible nonmetallic conduit; metal-clad cable; mineral-insulated, metal-sheathed cable; multiconductor service-entrance cable; multiconductor underground feeder and branch-circuit cable; multipurpose and communications cables; nonmetallicsheathed cable; power and control tray cable; power-limited tray cable; optical fiber cables; and other factory-assembled, multiconductor control, signal, or power cables that are specifically approved for installation in cable trays, rigid metal conduit, and rigid nonmetallic conduit. [§1910.305(a)(3)(i)] (ii) In industrial establishments where conditions of maintenance and supervision assure that only qualified persons will service the installed cable tray system, the following cables may also be installed in ladder, ventilated-trough, or ventilated-channel cable trays: [§1910.305(a)(3)(ii)] [A] Single conductor cable; the cable shall be No. 1/0 or larger and shall be of a type listed and marked on the surface for use in cable trays; where Nos. 1/0 through 4/ 0 single conductor cables are installed in ladder cable tray, the maximum allowable rung spacing for the ladder cable tray shall be 229 mm (9 in.); where exposed to direct rays of the sun, cables shall be identified as being sunlight resistant; [§1910.305(a)(3)(ii)[A]]

Wiring methods, components, and equipment for general use [B] Welding cables installed in dedicated cable trays; [§1910.305(a)(3)(ii)[B]]

[C] Single conductors used as equipment grounding conductors; these conductors, which may be insulated, covered, or bare, shall be No. 4 or larger; and [§1910.305(a)(3)(ii)[C]]

[§1910.305(a)(4)(i)]

(ii) Conductors smaller than No. 8 shall be rigidly supported on noncombustible, nonabsorbent insulating materials and may not contact any other objects. Supports shall be installed as follows: [§1910.305(a)(4)(ii)] [A] Within 152 mm (6 in.) from a tap or splice; [§1910.305(a)(4)(ii)[A]]

[B] Within 305 mm (12 in.) of a dead-end connection to a lampholder or receptacle; and [§1910.305(a)(4)(ii)[B]] [C] At intervals not exceeding 1.37 m (4.5 ft), and at closer intervals sufficient to provide adequate support where likely to be disturbed. [§1910.305(a)(4)(ii)[C]] (iii) In dry locations, where not exposed to severe physical damage, conductors may be separately enclosed in flexible nonmetallic tubing. The tubing shall be in continuous lengths not exceeding 4.57 m (15.0 ft) and secured to the surface by straps at intervals not exceeding 1.37 m (4.5 ft). [§1910.305(a)(4)(iii)]

(iv) Open conductors shall be separated from contact with walls, floors, wood cross members, or partitions through which they pass by tubes or bushings of noncombustible, nonabsorbent insulating material. If the bushing is shorter than the hole, a waterproof sleeve of nonconductive material shall be inserted in the hole and an insulating bushing slipped into the sleeve at each end in such a manner as to keep the conductors absolutely out of contact with the sleeve. Each conductor shall be carried through a separate tube or sleeve. [§1910.305(a)(4)(iv)] (v) Where open conductors cross ceiling joints and wall studs and are exposed to physical damage (for example, located within 2.13 m (7.0 ft) of the floor), they shall be protected. [§1910.305(a)(4)(v)]

(b)  Cabinets, boxes, and fittings. [§1910.305(b)] (1) Conductors entering boxes, cabinets, or fittings. [§1910.305(b)(1)] (i) Conductors entering cutout boxes, cabinets, or fittings shall be protected from abrasion, and openings through which conductors enter shall be effectively closed. [§1910.305(b)(1)(i)] (ii) Unused openings in cabinets, boxes, and fittings shall be effectively closed. [§1910.305(b)(1)(ii)] (iii) Where cable is used, each cable shall be secured to the cabinet, cutout box, or meter socket enclosure. However, where cable with an entirely nonmetallic sheath enters the top of a surface-mounted enclosure through one or more nonflexible raceways not less than 457 mm (18 in.) or more than 3.05 m (10.0 ft) in length, the cable need not be secured to the cabinet, box, or enclosure provided all of the following conditions are met: [§1910.305(b)(1)(iii)] [A] Each cable is fastened within 305 mm (12 in.) of the outer end of the raceway, measured along the sheath; [§1910.305(b)(1)(iii)[A]]

[B] The raceway extends directly above the enclosure and does not penetrate a structural ceiling; [§1910.305(b)(1)(iii)[B]]

[C] A fitting is provided on each end of the raceway to protect the cable from abrasion, and the fittings remain accessible after installation; [§1910.305(b)(1)(iii)[C]]

[D] The raceway is sealed or plugged at the outer end using approved means so as to prevent access to the enclosure through the raceway; [§1910.305(b)(1)(iii)[D]] [E] The cable sheath is continuous through the raceway and extends into the enclosure not less than 6.35 mm (0.25 in.) beyond the fitting; [§1910.305(b)(1)(iii)[E]] [F] The raceway is fastened at its outer end and at other points as necessary; and [§1910.305(b)(1)(iii)[F]] [G] Where installed as conduit or tubing, the allowable cable fill does not exceed that permitted for complete conduit or tubing systems. [§1910.305(b)(1)(iii)[G]] (2) Covers and canopies. [§1910.305(b)(2)] (i) All pull boxes, junction boxes, and fittings shall be provided with covers identified for the purpose. If metal covers are used, they shall be grounded. In completed installations, each outlet box shall have a cover, faceplate, or fixture canopy. Covers of outlet boxes having holes through which flexible cord pendants pass shall be provided with bushings designed for the purpose or shall have smooth, wellrounded surfaces on which the cords may bear. [§1910.305(b)(2)(i)]

(ii) Where a fixture canopy or pan is used, any combustible wall or ceiling finish exposed between the edge of the canopy or pan and the outlet box shall be covered with noncombustible material. [§1910.305(b)(2)(ii)] (3) Pull and junction boxes for systems over 600 volts, nominal. In addition to other requirements in this section, the following requirements apply to pull and junction boxes for systems over 600 volts, nominal: [§1910.305(b)(3)] (i) Boxes shall provide a complete enclosure for the contained conductors or cables. [§1910.305(b)(3)(i)] (ii) Boxes shall be closed by suitable covers securely fastened in place. [§1910.305(b)(3)(ii)] Note to paragraph (b)(3)(ii) of this section: Underground box covers that weigh over 45.4 kg (100 lbs) meet this requirement.

(iii) Covers for boxes shall be permanently marked "HIGH VOLTAGE.” The marking shall be on the outside of the box cover and shall be readily visible and legible. [§1910.305(b)(3)(iii)] (c) Switches. [§1910.305(c)] (1) Single-throw knife switches. Single-throw knife switches shall be so placed that gravity will not tend to close them. Singlethrow knife switches approved for use in the inverted position shall be provided with a locking device that will ensure that the blades remain in the open position when so set. [§1910.305(c)(1)] (2) Double-throw knife switches. Double-throw knife switches may be mounted so that the throw will be either vertical or horizontal. However, if the throw is vertical, a locking device shall be provided to ensure that the blades remain in the open position when so set. [§1910.305(c)(2)] (3) Connection of switches. [§1910.305(c)(3)] (i) Single-throw knife switches and switches with butt contacts shall be connected so that the blades are deenergized when the switch is in the open position. [§1910.305(c)(3)(i)] (ii) Single-throw knife switches, molded-case switches, switches with butt contacts, and circuit breakers used as switches shall be connected so that the terminals supplying the load are deenergized when the switch is in the open position. However, blades and terminals supplying the load of a switch may be energized when the switch is in the open position where the switch is connected to circuits or equipment inherently capable of providing a backfeed source of power. For such installations, a permanent sign shall be installed on the switch enclosure or immediately adjacent to open switches that read, [§1910.305(c)(3)(ii)]

"WARNING — LOAD SIDE TERMINALS MAY BE ENERGIZED BY BACKFEED." (4) Faceplates for flush-mounted snap switches. Snap switches mounted in boxes shall have faceplates installed so as to completely cover the opening and seat against the finished surface. [§1910.305(c)(4)]

(5) Grounding. Snap switches, including dimmer switches, shall be effectively grounded and shall provide a means to ground metal faceplates, whether or not a metal faceplate is installed.

However, if no grounding means exists within the snap-switch enclosure, or where the wiring method does not include or provide an equipment ground, a snap switch without a grounding connection is permitted for replacement purposes only. Such snap switches shall be provided with a faceplate of nonconducting, noncombustible material if they are located within reach of conducting floors or other conducting surfaces. [§1910.305(c)(5)]

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[D] Multiconductor cable, Type MV; where exposed to direct rays of the sun, the cable shall be identified as being sunlight resistant. [§1910.305(a)(3)(ii)[D]] (iii) Metallic cable trays may be used as equipment grounding conductors only where continuous maintenance and supervision ensure that qualified persons will service the installed cable tray system. [§1910.305(a)(3)(iii)] (iv) Cable trays in hazardous (classified) locations may contain only the cable types permitted in such locations. (See §1910.307.) [§1910.305(a)(3)(iv)] (v) Cable tray systems may not be used in hoistways or where subjected to severe physical damage. [§1910.305(a)(3)(v)] (4) Open wiring on insulators. [§1910.305(a)(4)] (i) Open wiring on insulators is only permitted on systems of 600 volts, nominal, or less for industrial or agricultural establishments, indoors or outdoors, in wet or dry locations, where subject to corrosive vapors, and for services.

§1910.305(c)

§1910.305

Subpart S – Electrical

(d) Switchboards and panelboards. [§1910.305(d)] (1) Switchboards with exposed live parts. Switchboards that have any exposed live parts shall be located in permanently dry locations and shall be accessible only to qualified persons. [§1910.305(d)(1)] (2) Panelboard enclosures. Panelboards shall be mounted in cabinets, cutout boxes, or enclosures designed for the purpose and shall be dead front. However, panelboards other than the dead front externally-operable type are permitted where accessible only to qualified persons. [§1910.305(d)(2)] (3) Knife switches mounted in switchboards or panelboards. Exposed blades of knife switches mounted in switchboards or panelboards shall be dead when open. [§1910.305(d)(3)] (e) Enclosures for damp or wet locations. [§1910.305(e)] (1) Cabinets, cutout boxes, fittings, boxes, and panelboard enclosures.

Cabinets, cutout boxes, fittings, boxes, and panelboard enclosures in damp or wet locations shall be installed so as to prevent moisture or water from entering and accumulating within the enclosures and shall be mounted so there is at least 6.35-mm (0.25-in.) airspace between the enclosure and the wall or other supporting surface.

However, nonmetallic enclosures may be installed without the airspace on a concrete, masonry, tile, or similar surface. The enclosures shall be weatherproof in wet locations. [§1910.305(e)(1)] (2) Switches, circuit breakers, and switchboards. Switches, circuit breakers, and switchboards installed in wet locations shall be enclosed in weatherproof enclosures. [§1910.305(e)(2)] (f) Conductors for general wiring. [§1910.305(f)] (1) Insulation. All conductors used for general wiring shall be insulated unless otherwise permitted in this subpart. [§1910.305(f)(1)] (2) Type. The conductor insulation shall be of a type that is approved for the voltage, operating temperature, and location of use. [§1910.305(f)(2)] (3) Distinguishable. Insulated conductors shall be distinguishable by appropriate color or other suitable means as being grounded conductors, ungrounded conductors, or equipment grounding conductors. [§1910.305(f)(3)] (g)  Flexible cords and cables. [§1910.305(g)] (1)  Use of flexible cords and cables. [§1910.305(g)(1)] (i)  Flexible cords and cables shall be approved for conditions of use and location. [§1910.305(g)(1)(i)] (ii)  Flexible cords and cables may be used only for: [§1910.305(g)(1)(ii)]

[A] Pendants; [§1910.305(g)(1)(ii)[A]] [B] Wiring of fixtures; [§1910.305(g)(1)(ii)[B]] [C] Connection of portable lamps or appliances; [§1910.305(g)(1)(ii)[C]]

[D] Portable and mobile signs; [§1910.305(g)(1)(ii)[D]] [E] Elevator cables; [§1910.305(g)(1)(ii)[E]] [F] Wiring of cranes and hoists; [§1910.305(g)(1)(ii)[F]] [G] Connection of stationary equipment to facilitate their frequent interchange; [§1910.305(g)(1)(ii)[G]] [H] Prevention of the transmission of noise or vibration; [§1910.305(g)(1)(ii)[H]]

[I] Appliances where the fastening means and mechanical connections are designed to permit removal for maintenance and repair; [§1910.305(g)(1)(ii)[I]] [J] Data processing cables approved as a part of the data processing system; [§1910.305(g)(1)(ii)[J]] [K] Connection of moving parts; and [§1910.305(g)(1)(ii)[K]] [L] Temporary wiring as permitted in paragraph (a)(2) of this section. [§1910.305(g)(1)(ii)[L]] (iii)  If used as permitted in paragraphs (g)(1)(ii)(C), (g)(1)(ii)(G), or (g)(1)(ii)(I) of this section, the flexible cord shall be equipped with an attachment plug and shall be energized from an approved receptacle outlet. [§1910.305(g)(1)(iii)]

(iv)  Unless specifically permitted otherwise in paragraph (g)(1)(ii) of this section, flexible cords and cables may not be used: [§1910.305(g)(1)(iv)] [A] As a substitute for the fixed wiring of a structure; [§1910.305(g)(1)(iv)[A]]

[B] Where run through holes in walls, ceilings, or floors; [§1910.305(g)(1)(iv)[B]]

[C] Where run through doorways, windows, or similar openings; [§1910.305(g)(1)(iv)[C]] [D] Where attached to building surfaces; [§1910.305(g)(1)(iv)[D]]

[E] Where concealed behind building walls, ceilings, or floors; or [§1910.305(g)(1)(iv)[E]] [F] Where installed in raceways, except as otherwise permitted in this subpart. [§1910.305(g)(1)(iv)[F]]

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(v) Flexible cords used in show windows and showcases shall be Type S, SE, SEO, SEOO, SJ, SJE, SJEO, SJEOO, SJO, SJOO, SJT, SJTO, SJTOO, SO, SOO, ST, STO, or STOO, except for the wiring of chain-supported lighting fixtures and supply cords for portable lamps and other merchandise being displayed or exhibited. [§1910.305(g)(1)(v)] (2) Identification, splices, and terminations. [§1910.305(g)(2)] (i) A conductor of a flexible cord or cable that is used as a grounded conductor or an equipment grounding conductor shall be distinguishable from other conductors. Types S, SC, SCE, SCT, SE, SEO, SEOO, SJ, SJE, SJEO, SJEOO, SJO, SJT, SJTO, SJTOO, SO, SOO, ST, STO, and STOO flexible cords and Types G, G-GC, PPE, and W flexible cables shall be durably marked on the surface at intervals not exceeding 610 mm (24 in.) with the type designation, size, and number of conductors. [§1910.305(g)(2)(i)] (ii) Flexible cords may be used only in continuous lengths without splice or tap. Hard-service cord and junior hard-service cord No. 14 and larger may be repaired if spliced so that the splice retains the insulation, outer sheath properties, and usage characteristics of the cord being spliced. [§1910.305(g)(2)(ii)]

(iii)  Flexible cords and cables shall be connected to devices and fittings so that strain relief is provided that will prevent pull from being directly transmitted to joints or terminal screws. [§1910.305(g)(2)(iii)]

(h) Portable cables over 600 volts, nominal. This paragraph applies to portable cables used at more than 600 volts, nominal. [§1910.305(h)] (1) Conductor construction. Multiconductor portable cable for use in supplying power to portable or mobile equipment at over 600 volts, nominal, shall consist of No. 8 or larger conductors employing flexible stranding. However, the minimum size of the insulated ground-check conductor of Type G-GC cables shall be No. 10. [§1910.305(h)(1)] (2) Shielding. Cables operated at over 2,000 volts shall be shielded for the purpose of confining the voltage stresses to the insulation. [§1910.305(h)(2)]

(3) Equipment grounding conductors. Grounding conductors shall be provided. [§1910.305(h)(3)] (4) Grounding shields. All shields shall be grounded. [§1910.305(h)(4)]

(5) Minimum bending radii. The minimum bending radii for portable cables during installation and handling in service shall be adequate to prevent damage to the cable. [§1910.305(h)(5)] (6) Fittings. Connectors used to connect lengths of cable in a run shall be of a type that lock firmly together. Provisions shall be made to prevent opening or closing these connectors while energized. Strain relief shall be provided at connections and terminations. [§1910.305(h)(6)] (7) Splices. Portable cables may not be operated with splices unless the splices are of the permanent molded, vulcanized, or other approved type. [§1910.305(h)(7)] (8) Terminations. Termination enclosures shall be suitably marked with a high voltage hazard warning, and terminations shall be accessible only to authorized and qualified employees. [§1910.305(h)(8)] (i) Fixture wires. [§1910.305(i)] (1) General. Fixture wires shall be approved for the voltage, temperature, and location of use. A fixture wire which is used as a grounded conductor shall be identified. [§1910.305(i)(1)] (2) Uses permitted. Fixture wires may be used only: [§1910.305(i)(2)] (i) For installation in lighting fixtures and in similar equipment where enclosed or protected and not subject to bending or twisting in use; or [§1910.305(i)(2)(i)] (ii) For connecting lighting fixtures to the branch-circuit conductors supplying the fixtures. [§1910.305(i)(2)(ii)] (3) Uses not permitted. Fixture wires may not be used as branchcircuit conductors except as permitted for Class 1 power limited circuits and for fire alarm circuits. [§1910.305(i)(3)] (j) Equipment for general use. [§1910.305(j)] (1) Lighting fixtures, lampholders, lamps, and receptacles. [§1910.305(j)(1)]

(i) Fixtures, lampholders, lamps, rosettes, and receptacles may have no live parts normally exposed to employee contact.

However, rosettes and cleat-type lampholders and receptacles located at least 2.44 m (8.0 ft) above the floor may have exposed terminals. [§1910.305(j)(1)(i)] (ii) Handlamps of the portable type supplied through flexible cords shall be equipped with a handle of molded composition or other material identified for the purpose, and a substantial guard shall be attached to the lampholder or the handle. Metal shell, paperlined lampholders may not be used. [§1910.305(j)(1)(ii)]

Special systems (c) Class 1, Class 2, and Class 3 remote control, signaling, and powerlimited circuits [§1910.308(c)] (1) Classification. Class 1, Class 2, and Class 3 remote control, signaling, or power-limited circuits are characterized by their usage and electrical power limitation that differentiates them from light and power circuits. These circuits are classified in accordance with their respective voltage and power limitations as summarized in paragraphs (c)(1)(i) through (c)(1)(iii) of this section. [§1910.308(c)(1)] (i) A Class 1 power-limited circuit shall be supplied from a source having a rated output of not more than 30 volts and 1000 volt-amperes. [§1910.308(c)(1)(i)] (ii) A Class 1 remote control circuit or a Class 1 signaling circuit shall have a voltage not exceeding 600 volts; however, the power output of the source need not be limited. [§1910.308(c)(1)(ii)]

[§1910.308(c)(1)(iii)[B]]

(2) Marking. A Class 2 or Class 3 power supply unit shall be durably marked where plainly visible to indicate the class of supply and its electrical rating. [§1910.308(c)(2)] (3) Separation from conductors of other circuits. Cables and conductors of Class 2 and Class 3 circuits may not be placed in any cable, cable tray, compartment, enclosure, manhole, outlet box, device box, raceway, or similar fitting with conductors of electric light, power, Class 1, nonpower-limited fire alarm circuits, and medium power network-powered broadband communications cables unless a barrier or other equivalent form of protection against contact is employed. [§1910.308(c)(3)] (d) Fire alarm systems [§1910.308(d)] (1) Classifications. Fire alarm circuits shall be classified either as nonpower limited or power limited. [§1910.308(d)(1)] (2) Power sources. The power sources for use with fire alarm circuits shall be either power limited or nonpower limited as follows: [§1910.308(d)(2)]

(i) The power source of nonpower-limited fire alarm (NPLFA) circuits shall have an output voltage of not more than 600 volts, nominal; and [§1910.308(d)(2)(i)] (ii) The power source for a power-limited fire alarm (PLFA) circuit shall be listed equipment marked as a PLFA power source. [§1910.308(d)(2)(ii)] (3) Separation from conductors of other circuits. [§1910.308(d)(3)] (i) Nonpower-limited fire alarm circuits and Class 1 circuits may occupy the same enclosure, cable, or raceway provided all conductors are insulated for maximum voltage of any conductor within the enclosure, cable, or raceway.

Power supply and fire alarm circuit conductors are permitted in the same enclosure, cable, or raceway only if connected to the same equipment. [§1910.308(d)(3)(i)] (ii) Power-limited circuit cables and conductors may not be placed in any cable, cable tray, compartment, enclosure, outlet box, raceway, or similar fitting with conductors of electric light, power, Class 1, nonpower-limited fire alarm circuit conductors, or medium power network-powered broadband communications circuits. [§1910.308(d)(3)(ii)] (iii) Power-limited fire alarm circuit conductors shall be separated at least 50.8 mm (2 in.) from conductors of any electric light, power, Class 1, nonpower-limited fire alarm, or medium power network-powered broadband communications circuits unless a special and equally protective method of conductor separation is employed. [§1910.308(d)(3)(iii)]

(iv) Conductors of one or more Class 2 circuits are permitted within the same cable, enclosure, or raceway with conductors of power-limited fire alarm circuits provided that the insulation of Class 2 circuit conductors in the cable, enclosure, or raceway is at least that needed for the power-limited fire alarm circuits. [§1910.308(d)(3)(iv)] (4) Identification. Fire alarm circuits shall be identified at terminal and junction locations in a manner that will prevent unintentional interference with the signaling circuit during testing and servicing. Power-limited fire alarm circuits shall be durably marked as such where plainly visible at terminations. [§1910.308(d)(4)]

(e) Communications systems. This paragraph applies to centralstation-connected and non-central-station-connected telephone circuits, radio and television receiving and transmitting equipment, including community antenna television and radio distribution systems, telegraph, district messenger, and outside wiring for fire and burglar alarm, and similar central station systems. These installations need not comply with the provisions of §1910.303 through §1910.308(d), except for §1910.304(c)(1) and §1910.307. [§1910.308(e)]

(1) Protective devices. [§1910.308(e)(1)] (i) A listed primary protector shall be provided on each circuit run partly or entirely in aerial wire or aerial cable not confined within a block. [§1910.308(e)(1)(i)] (ii) A listed primary protector shall be also provided on each aerial or underground circuit when the location of the circuit within the block containing the building served allows the circuit to be exposed to accidental contact with electric light or power conductors operating at over 300 volts to ground. [§1910.308(e)(1)(ii)]

(iii) In addition, where there exists a lightning exposure, each interbuilding circuit on premises shall be protected by a listed primary protector at each end of the interbuilding circuit. [§1910.308(e)(1)(iii)]

(2) Conductor location. [§1910.308(e)(2)] (i) Lead-in or aerial-drop cables from a pole or other support, including the point of initial attachment to a building or structure, shall be kept away from electric light, power, Class 1, or nonpower-limited fire alarm circuit conductors so as to avoid the possibility of accidental contact. [§1910.308(e)(2)(i)] (ii) A separation of at least 1.83 m (6 ft) shall be maintained between communications wires and cables on buildings and lightning conductors. [§1910.308(e)(2)(ii)] (iii) Where communications wires and cables and electric light or power conductors are supported by the same pole or run parallel to each other in-span, the following conditions shall be met: [§1910.308(e)(2)(iii)] [A] Where practicable, communication wires and cables on poles shall be located below the electric light or power conductors; and [§1910.308(e)(2)(iii)[A]] [B] Communications wires and cables may not be attached to a crossarm that carries electric light or power conductors. [§1910.308(e)(2)(iii)[B]]

(iv) Indoor communications wires and cables shall be separated at least 50.8 mm (2 in.) from conductors of any electric light, power, Class 1, nonpower-limited fire alarm, or medium power network-powered broadband communications circuits, unless a special and equally protective method of conductor separation, identified for the purpose, is employed. [§1910.308(e)(2)(iv)] (3) Equipment location. Outdoor metal structures supporting antennas, as well as self-supporting antennas such as vertical rods or dipole structures, shall be located as far away from overhead conductors of electric light and power circuits of over 150 volts to ground as necessary to prevent the antenna or structure from falling into or making accidental contact with such circuits. [§1910.308(e)(3)] (4) Grounding. [§1910.308(e)(4)] (i) If exposed to contact with electric light and power conductors, the metal sheath of aerial cables entering buildings shall be grounded or shall be interrupted close to the entrance to the building by an insulating joint or equivalent device. Where protective devices are used, they shall be grounded in an approved manner. [§1910.308(e)(4)(i)] (ii) Masts and metal structures supporting antennas shall be permanently and effectively grounded without splice or connection in the grounding conductor. [§1910.308(e)(4)(ii)] (iii) Transmitters shall be enclosed in a metal frame or grill or separated from the operating space by a barrier, all metallic parts of which are effectively connected to ground. All external metal handles and controls accessible to the operating personnel shall be effectively grounded. Unpowered equipment and enclosures are considered to be grounded where connected to an attached coaxial cable with an effectively grounded metallic shield. [§1910.308(e)(4)(iii)] (f) Solar photovoltaic systems. This paragraph covers solar photovoltaic systems that can be interactive with other electric power production sources or can stand alone with or without electrical energy storage such as batteries. These systems may have ac or dc output for utilization. [§1910.308(f)] (1) Conductors of different systems. Photovoltaic source circuits and photovoltaic output circuits may not be contained in the same raceway, cable tray, cable, outlet box, junction box, or similar fitting as feeders or branch circuits of other systems,

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(iii) The power source for a Class 2 or Class 3 circuit shall be listed equipment marked as a Class 2 or Class 3 power source, except as follows: [§1910.308(c)(1)(iii)] [A] Thermocouples do not require listing as a Class 2 power source; and [§1910.308(c)(1)(iii)[A]] [B] A dry cell battery is considered an inherently limited Class 2 power source, provided the voltage is 30 volts or less and the capacity is less than or equal to that available from series-connected No. 6 carbon zinc cells.

§1910.308(f)

§1910.331

Subpart S – Electrical

unless the conductors of the different systems are separated by a partition or are connected together. [§1910.308(f)(1)] (2) Disconnecting means. Means shall be provided to disconnect all current-carrying conductors of a photovoltaic power source from all other conductors in a building or other structure. Where a circuit grounding connection is not designed to be automatically interrupted as part of the ground-fault protection system, a switch or circuit breaker used as disconnecting means may not have a pole in the grounded conductor. [§1910.308(f)(2)] (g) Integrated electrical systems [§1910.308(g)] (1) Scope. Paragraph (g) of this section covers integrated electrical systems, other than unit equipment, in which orderly shutdown is necessary to ensure safe operation. An integrated electrical system as used in this section shall be a unitized segment of an industrial wiring system where all of the following conditions are met: [§1910.308(g)(1)] (i) An orderly shutdown process minimizes employee hazard and equipment damage; [§1910.308(g)(1)(i)] (ii) The conditions of maintenance and supervision ensure that only qualified persons will service the system; and [§1910.308(g)(1)(ii)]

(iii) Effective safeguards are established and maintained. [§1910.308(g)(1)(iii)]

(2) Location of overcurrent devices in or on premises. Overcurrent devices that are critical to integrated electrical systems need not be readily accessible to employees as required by §1910.304(f)(1)(iv) if they are located with mounting heights to ensure security from operation by nonqualified persons. [§1910.308(g)(2)]

§§1910.309-1910.330 [Reserved] SAFETY-RELATED WORK PRACTICES §1910.331  Scope (a)  Covered work by both qualified and unqualified persons.

The provisions of §§1910.331 through 1910.335 cover electrical safety-related work practices for both qualified persons (those who have training in avoiding the electrical hazards of working on or near exposed energized parts) and unqualified persons (those with little or no such training) working on, near, or with the following installations: [§1910.331(a)] (1) Premises wiring. Installations of electric conductors and equipment within or on buildings or other structures, and on other premises such as yards, carnival, parking, and other lots, and industrial substations; [§1910.331(a)(1)] (2) Wiring for connection to supply. Installations of conductors that connect to the supply of electricity; and [§1910.331(a)(2)] (3) Other wiring. Installations of other outside conductors on the premises. [§1910.331(a)(3)] (4) Optical fiber cable. Installations of optical fiber cable where such installations are made along with electric conductors. [§1910.331(a)(4)] Note: See §1910.399 for the definition of "qualified person.” See §1910.332 for training requirements that apply to qualified and unqualified persons.

(b)  Other covered work. The provisions of §§1910.331 through 1910.335 also cover: [§1910.331(b)] (1) Work performed by unqualified persons on, near, or with the installations listed in paragraphs (c)(1) through (4) of this section; and [§1910.331(b)(1)] (2) Work performed by qualified persons near the installations listed in paragraphs (c)(1) through (c)(4) of this section when that work is not on or directly associated with those installations. [§1910.331(b)(2)]

(c) Excluded work by qualified persons. The provisions of §§1910.331 through 1910.335 do not apply to work performed by qualified persons on or directly associated with the following installations: [§1910.331(c)] (1)  Generation, transmission, and distribution installations.

Installations for the generation, control, transformation, transmission, and distribution of electric energy (including communication and metering) located in buildings used for such purposes or located outdoors. [§1910.331(c)(1)] Note 1 to paragraph (c)(1): Work on or directly associated with installations of utilization equipment used for purposes other than generating, transmitting, or distributing electric energy (such as installations which are in office buildings, warehouses, garages, machine shops, or recreational buildings, or other utilization installations which are not an integral part of a generating installation, substation, or control center) is covered under paragraph (a)(1) of this section.

Note 2 to paragraph (c)(1): For work on or directly associated with utilization installations, an employer who complies with the work practices of §1910.269 (electric power generation, transmission, and distribution) will be deemed to be in compliance with §§1910.333(c) and 1910.335. However, the requirements of §§1910.332, 1910.333(a), 1910.333(b), and 1910.334 apply to all work on or directly associated with utilization installations, regardless of whether the work is performed by qualified or unqualified persons.

Note 3 to paragraph (c)(1): Work on or directly associated with generation, transmission, or distribution installations includes:

36

(1) Work performed directly on such installations, such as repairing overhead or underground distribution lines or repairing a feed-water pump for the boiler in a generating plant. [§1910.331(c)(1)(1)]

(2) Work directly associated with such installations, such as lineclearance tree trimming and replacing utility poles, when that work is covered by §1910.269 (see §1910.269(a)(1)(i)(D) and (E) and the definition of "line-clearance tree trimming” in §1910.269(x)). [§1910.331(c)(1)(2)] (3) Work on electric utilization circuits in a generating plant provided that: [§1910.331(c)(1)(3)] [A] Such circuits are commingled with installations of power generation equipment or circuits, and [§1910.331(c)(1)(3)[A]]

[B] The generation equipment or circuits present greater electrical hazards than those posed by the utilization equipment or circuits (such as exposure to higher voltages or lack of overcurrent protection). [§1910.331(c)(1)(3)[B]]

This work is covered by §1910.269.

(2) Communications installations. Installations of communication equipment to the extent that the work is covered under §1910.268. [§1910.331(c)(2)]

(3) Installations in vehicles. Installations in ships, watercraft, railway rolling stock, aircraft, or automotive vehicles other than mobile homes and recreational vehicles. [§1910.331(c)(3)] (4) Railway installations. Installations of railways for generation, transformation, transmission, or distribution of power used exclusively for operation of rolling stock or installations of railways used exclusively for signaling and communication purposes. [§1910.331(c)(4)] [55 FR 32016, Aug. 6, 1990, as amended at 59 FR 4476, Jan. 31, 1994; 79 FR 20692, Apr. 11, 2014; 80 FR 60039, Oct. 5, 2015]

§1910.332  Training (a)  Scope. The training requirements contained in this section apply to employees who face a risk of electric shock that is not reduced to a safe level by the electrical installation requirements of §§1910.303 through 1910.308. [§1910.332(a)] Note: Employees in occupations listed in Table S-4 face such a risk and are required to be trained. Other employees who also may reasonably be expected to face a comparable risk of injury due to electric shock or other electrical hazards must also be trained. (b) Content of training. [§1910.332(b)]

(1) Practices addressed in this standard. Employees shall be trained in and familiar with the safety-related work practices required by §§1910.331 through 1910.335 that pertain to their respective job assignments. [§1910.332(b)(1)] (2) Additional requirements for unqualified persons. Employees who are covered by paragraph (a) of this section but who are not qualified persons shall also be trained in and familiar with any electrically related safety practices not specifically addressed by §§1910.331 through 1910.335 but which are necessary for their safety. [§1910.332(b)(2)] (3) Additional requirements for qualified persons. Qualified persons (i.e., those permitted to work on or near exposed energized parts) shall, at a minimum, be trained in and familiar with the following: [§1910.332(b)(3)] (i) The skills and techniques necessary to distinguish exposed live parts from other parts of electric equipment, [§1910.332(b)(3)(i)]

(ii) The skills and techniques necessary to determine the nominal voltage of exposed live parts, and [§1910.332(b)(3)(ii)] (iii) The clearance distances specified in §1910.333(c) and the corresponding voltages to which the qualified person will be exposed. [§1910.332(b)(3)(iii)] Note 1: For the purposes of §§1910.331 through 1910.335, a person must have the training required by paragraph (b)(3) of this section in order to be considered a qualified person.

Note 2: Qualified persons whose work on energized equipment involves either direct contact or contact by means of tools or materials must also have the training needed to meet §1910.333(c)(2).

(c)  Type of training. The training required by this section shall be of the classroom or on-the-job type. The degree of training provided shall be determined by the risk to the employee. [§1910.332(c)]

Table S-4 — Typical Occupational Categories of Employees Facing a Higher Than Normal Risk of Electrical Accident Occupation Blue collar supervisors.1 Electrical and electronic engineers.1 Electrical and electronic equipment assemblers.1 Electrical and electronic technicians.1

Selection and use of work practices Table S-4 — Typical Occupational Categories of Employees Facing a Higher Than Normal Risk of Electrical Accident

(continued)

Occupation Electricians.

Industrial machine operators.1 Material handling equipment operators.1 Mechanics and repairers.1 Painters.1 Riggers and roustabouts.1 Stationary engineers.1 Welders.

1 Workers in these groups do not need to be trained if their work or the work of those they

supervise does not bring them or the employees they supervise close enough to exposed parts of electric circuits operating at 50 volts or more to ground for a hazard to exist.

[55 FR 32016, Aug. 6, 1990]

(a) General. Safety-related work practices shall be employed to prevent electric shock or other injuries resulting from either direct or indirect electrical contacts, when work is performed near or on equipment or circuits which are or may be energized. The specific safety-related work practices shall be consistent with the nature and extent of the associated electrical hazards. [§1910.333(a)] (1)  Deenergized parts. Live parts to which an employee may be exposed shall be deenergized before the employee works on or near them, unless the employer can demonstrate that deenergizing introduces additional or increased hazards or is infeasible due to equipment design or operational limitations.

Live parts that operate at less than 50 volts to ground need not be deenergized if there will be no increased exposure to electrical burns or to explosion due to electric arcs. [§1910.333(a)(1)] Note 1: Examples of increased or additional hazards include interruption of life support equipment, deactivation of emergency alarm systems, shutdown of hazardous location ventilation equipment, or removal of illumination for an area.

Note 2: Examples of work that may be performed on or near energized circuit parts because of infeasibility due to equipment design or operational limitations include testing of electric circuits that can only be performed with the circuit energized and work on circuits that form an integral part of a continuous industrial process in a chemical plant that would otherwise need to be completely shut down in order to permit work on one circuit or piece of equipment.

Note 3: Work on or near deenergized parts is covered by paragraph (b) of this section.

(2)  Energized parts. If the exposed live parts are not deenergized (i.e., for reasons of increased or additional hazards or infeasibility), other safety-related work practices shall be used to protect employees who may be exposed to the electrical hazards involved. Such work practices shall protect employees against contact with energized circuit parts directly with any part of their body or indirectly through some other conductive object. The work practices that are used shall be suitable for the conditions under which the work is to be performed and for the voltage level of the exposed electric conductors or circuit parts. Specific work practice requirements are detailed in paragraph (c) of this section. [§1910.333(a)(2)]

(b)  Working on or near exposed deenergized parts. [§1910.333(b)]

(1)  Application. This paragraph applies to work on exposed deenergized parts or near enough to them to expose the employee to any electrical hazard they present. Conductors and parts of electric equipment that have been deenergized but have not been locked out or tagged in accordance with paragraph (b) of this section shall be treated as energized parts, and paragraph (c) of this section applies to work on or near them. [§1910.333(b)(1)] (2)  Lockout and tagging. While any employee is exposed to contact with parts of fixed electric equipment or circuits which have been deenergized, the circuits energizing the parts shall be locked out or tagged or both in accordance with the requirements of this paragraph. The requirements shall be followed in the order in which they are presented (i.e., paragraph (b)(2)(i) first, then paragraph (b)(2)(ii), etc.). [§1910.333(b)(2)] Note 1: As used in this section, fixed equipment refers to equipment fastened in place or connected by permanent wiring methods.

Note 2: Lockout and tagging procedures that comply with paragraphs (c) through (f) of §1910.147 will also be deemed to comply with paragraph (b)(2) of this section provided that:

(1) The procedures address the electrical safety hazards covered by this Subpart; and [§1910.333(b)(2)(1)] (2) The procedures also incorporate the requirements of paragraphs (b)(2)(iii)(D) and (b)(2)(iv)(B) of this section. [§1910.333(b)(2)(2)]

(i) Procedures. The employer shall maintain a written copy of the procedures outlined in paragraph (b)(2) and shall make it available for inspection by employees and by the Assistant Secretary of Labor and his or her authorized representatives. [§1910.333(b)(2)(i)] Note: The written procedures may be in the form of a copy of paragraph (b) of this section. (ii) Deenergizing equipment. [§1910.333(b)(2)(ii)]

[A] Safe procedures for deenergizing circuits and equipment shall be determined before circuits or equipment are deenergized. [§1910.333(b)(2)(ii)[A]] [B] The circuits and equipment to be worked on shall be disconnected from all electric energy sources. Control circuit devices, such as push buttons, selector switches, and interlocks, may not be used as the sole means for deenergizing circuits or equipment. Interlocks for electric equipment may not be used as a substitute for lockout and tagging procedures. [§1910.333(b)(2)(ii)[B]] [C] Stored electric energy which might endanger personnel shall be released. Capacitors shall be discharged and high capacitance elements shall be short-circuited and grounded, if the stored electric energy might endanger personnel. [§1910.333(b)(2)(ii)[C]] Note: If the capacitors or associated equipment are handled in meeting this requirement, they shall be treated as energized.

[D] Stored non-electrical energy in devices that could reenergize electric circuit parts shall be blocked or relieved to the extent that the circuit parts could not be accidentally energized by the device. [§1910.333(b)(2)(ii)[D]] (iii) Application of locks and tags. [§1910.333(b)(2)(iii)] [A] A lock and a tag shall be placed on each disconnecting means used to deenergize circuits and equipment on which work is to be performed, except as provided in paragraphs (b)(2)(iii)(C) and (b)(2)(iii)(E) of this section.

The lock shall be attached so as to prevent persons from operating the disconnecting means unless they resort to undue force or the use of tools. [§1910.333(b)(2)(iii)[A]]

[B] Each tag shall contain a statement prohibiting unauthorized operation of the disconnecting means and removal of the tag. [§1910.333(b)(2)(iii)[B]] [C] If a lock cannot be applied, or if the employer can demonstrate that tagging procedures will provide a level of safety equivalent to that obtained by the use of a lock, a tag may be used without a lock. [§1910.333(b)(2)(iii)[C]]

[D] A tag used without a lock, as permitted by paragraph (b)(2)(iii)(C) of this section, shall be supplemented by at least one additional safety measure that provides a level of safety equivalent to that obtained by the use of a lock. Examples of additional safety measures include the removal of an isolating circuit element, blocking of a controlling switch, or opening of an extra disconnecting device. [§1910.333(b)(2)(iii)[D]] [E]  A lock may be placed without a tag only under the following conditions: [§1910.333(b)(2)(iii)[E]] [1] Only one circuit or piece of equipment is deenergized, and [§1910.333(b)(2)(iii)[E][1]] [2] The lockout period does not extend beyond the work shift, and [§1910.333(b)(2)(iii)[E][2]] [3] Employees exposed to the hazards associated with reenergizing the circuit or equipment are familiar with this procedure. [§1910.333(b)(2)(iii)[E][3]] (iv) Verification of deenergized condition. The requirements of this paragraph shall be met before any circuits or equipment can be considered and worked as deenergized. [§1910.333(b)(2)(iv)]

[A] A qualified person shall operate the equipment operating controls or otherwise verify that the equipment cannot be restarted. [§1910.333(b)(2)(iv)[A]] [B] A qualified person shall use test equipment to test the circuit elements and electrical parts of equipment to which employees will be exposed and shall verify that the circuit elements and equipment parts are deenergized. The test shall also determine if any energized condition exists as a result of inadvertently induced voltage or unrelated voltage backfeed even though specific parts of the circuit have been deenergized and presumed to be safe. If the circuit to be tested is over 600 volts, nominal, the test equipment shall be checked for proper operation immediately before and immediately after this test. [§1910.333(b)(2)(iv)[B]]

37

S Electrical

§1910.333  Selection and use of work practicesSelectionanduseofworkpractices

§1910.333(b)

§1910.333

Subpart S – Electrical (v) Reenergizing equipment. These requirements shall be met, in the order given, before circuits or equipment are reenergized, even temporarily. [§1910.333(b)(2)(v)] [A] A qualified person shall conduct tests and visual inspections, as necessary, to verify that all tools, electrical jumpers, shorts, grounds, and other such devices have been removed, so that the circuits and equipment can be safely energized. [§1910.333(b)(2)(v)[A]] [B] Employees exposed to the hazards associated with reenergizing the circuit or equipment shall be warned to stay clear of circuits and equipment. [§1910.333(b)(2)(v)[B]] [C]  Each lock and tag shall be removed by the employee who applied it or under his or her direct supervision. However, if this employee is absent from the workplace, then the lock or tag may be removed by a qualified person designated to perform this task provided that: [§1910.333(b)(2)(v)[C]]

[1] The employer ensures that the employee who applied the lock or tag is not available at the workplace, and [§1910.333(b)(2)(v)[C][1]]

[2] The employer ensures that the employee is aware that the lock or tag has been removed before he or she resumes work at that workplace. [§1910.333(b)(2)(v)[C][2]]

[D] There shall be a visual determination that all employees are clear of the circuits and equipment. [§1910.333(b)(2)(v)[D]]

(c) Working on or near exposed energized parts. [§1910.333(c)] (1) Application. This paragraph applies to work performed on exposed live parts (involving either direct contact or contact by means of tools or materials) or near enough to them for employees to be exposed to any hazard they present. [§1910.333(c)(1)]

(2)  Work on energized equipment. Only qualified persons may work on electric circuit parts or equipment that have not been deenergized under the procedures of paragraph (b) of this section. Such persons shall be capable of working safely on energized circuits and shall be familiar with the proper use of special precautionary techniques, personal protective equipment, insulating and shielding materials, and insulated tools. [§1910.333(c)(2)]

(3) Overhead lines. If work is to be performed near overhead lines, the lines shall be deenergized and grounded, or other protective measures shall be provided before work is started. If the lines are to be deenergized, arrangements shall be made with the person or organization that operates or controls the electric circuits involved to deenergize and ground them. If protective measures, such as guarding, isolating, or insulating are provided, these precautions shall prevent employees from contacting such lines directly with any part of their body or indirectly through conductive materials, tools, or equipment. [§1910.333(c)(3)] Note: The work practices used by qualified persons installing insulating devices on overhead power transmission or distribution lines are covered by §1910.269 of this Part, not by §§1910.332 through 1910.335 of this Part. Under paragraph (c)(2) of this section, unqualified persons are prohibited from performing this type of work. (i) Unqualified persons. [§1910.333(c)(3)(i)]

[A] When an unqualified person is working in an elevated position near overhead lines, the location shall be such that the person and the longest conductive object he or she may contact cannot come closer to any unguarded, energized overhead line than the following distances: [§1910.333(c)(3)(i)[A]]

[1] For voltages to ground 50kV or below — 10 ft. (305 cm); [§1910.333(c)(3)(i)[A][1]] [2] For voltages to ground over 50kV — 10 ft. (305 cm) plus 4 in. (10 cm) for every 10kV over 50kV. [§1910.333(c)(3)(i)[A][2]]

[B] When an unqualified person is working on the ground in the vicinity of overhead lines, the person may not bring any conductive object closer to unguarded, energized overhead lines than the distances given in paragraph (c)(3)(i)(A) of this section. [§1910.333(c)(3)(i)[B]] Note: For voltages normally encountered with overhead power lines, objects which do not have an insulating rating for the voltage involved are considered to be conductive.

(ii) Qualified persons. When a qualified person is working in the vicinity of overhead lines, whether in an elevated position or on the ground, the person may not approach or take any conductive object without an approved insulating handle closer to exposed energized parts than shown in Table S-5 unless: [§1910.333(c)(3)(ii)] [A] The person is insulated from the energized part (gloves, with sleeves if necessary, rated for the voltage

involved are considered to be insulation of the person from the energized part on which work is performed), or [§1910.333(c)(3)(ii)[A]]

[B] The energized part is insulated both from all other conductive objects at a different potential and from the person, or [§1910.333(c)(3)(ii)[B]] [C] The person is insulated from all conductive objects at a potential different from that of the energized part. [§1910.333(c)(3)(ii)[C]]

Table S-5 — Approach Distances for Qualified Employees — Alternating Current Voltage range (phase to phase) 300V and less Over 300V, not over 750V

1 ft. 0 in. (30.5 cm).

Over 750V, not over 2kV

l ft. 6 in. (46 cm).

Over 2kV, not over 15kV

2 ft. 0 in. (61 cm).

Over 15kV, not over 37kV

3 ft. 0 in. (91 cm).

Over 37kV, not over 87.5kV

3 ft. 6 in. (107 cm).

Over 87.5kV, not over 121kV

4 ft. 0 in. (122 cm).

Over 121kV, not over 140kV

4 ft. 6 in. (137 cm).

(iii) Vehicular and mechanical equipment. [§1910.333(c)(3)(iii)] [A] Any vehicle or mechanical equipment capable of having parts of its structure elevated near energized overhead lines shall be operated so that a clearance of 10 ft.

(305 cm) is maintained. If the voltage is higher than 50kV, the clearance shall be increased 4 in. (10 cm) for every 10kV over that voltage. However, under any of the following conditions, the clearance may be reduced: [§1910.333(c)(3)(iii)[A]]

[1] If the vehicle is in transit with its structure lowered, the clearance may be reduced to 4 ft. (122 cm). If the voltage is higher than 50kV, the clearance shall be increased 4 in. (10 cm) for every 10kV over that voltage. [§1910.333(c)(3)(iii)[A][1]] [2] If insulating barriers are installed to prevent contact with the lines, and if the barriers are rated for the voltage of the line being guarded and are not a part of or an attachment to the vehicle or its raised structure, the clearance may be reduced to a distance within the designed working dimensions of the insulating barrier. [§1910.333(c)(3)(iii)[A][2]] [3] If the equipment is an aerial lift insulated for the voltage involved, and if the work is performed by a qualified person, the clearance (between the uninsulated portion of the aerial lift and the power line) may be reduced to the distance given in Table S-5. [§1910.333(c)(3)(iii)[A][3]]

[B] Employees standing on the ground may not contact the vehicle or mechanical equipment or any of its attachments, unless: [§1910.333(c)(3)(iii)[B]] [1] The employee is using protective equipment rated for the voltage; or [§1910.333(c)(3)(iii)[B][1]] [2] The equipment is located so that no uninsulated part of its structure (that portion of the structure that provides a conductive path to employees on the ground) can come closer to the line than permitted in paragraph (c)(3)(iii) of this section. [§1910.333(c)(3)(iii)[B][2]]

[C] If any vehicle or mechanical equipment capable of having parts of its structure elevated near energized overhead lines is intentionally grounded, employees working on the ground near the point of grounding may not stand at the grounding location whenever there is a possibility of overhead line contact. Additional precautions, such as the use of barricades or insulation, shall be taken to protect employees from hazardous ground potentials, depending on earth resistivity and fault currents, which can develop within the first few feet or more outward from the grounding point. [§1910.333(c)(3)(iii)[C]]

(4) Illumination. [§1910.333(c)(4)] (i) Employees may not enter spaces containing exposed energized parts, unless illumination is provided that enables the employees to perform the work safely. [§1910.333(c)(4)(i)] (ii) Where lack of illumination or an obstruction precludes observation of the work to be performed, employees may not perform tasks near exposed energized parts. Employees may not reach blindly into areas which may contain energized parts. [§1910.333(c)(4)(ii)]

38

Minimum approach distance Avoid contact.

Subpart R – Special Industries Subpart R – Special Industries §1910.261  Pulp, paper, and paperboard millsPulp,paper, andpaperboardm ills (a)  General requirements — [§1910.261(a)] (1)  Application. This section applies to establishments where pulp, paper, and paperboard are manufactured and converted.

This section does not apply to logging and the transportation of logs to pulp, paper, and paperboard mills. [§1910.261(a)(1)] (2) Standards incorporated by reference. Standards covering issues of occupational safety and health which have general application without regard to any specific industry are incorporated by reference in paragraphs (b) through (m) of this section and in subparagraphs (3) and (4) of this paragraph and made applicable under this section. Such standards shall be construed according to the rules set forth in §1910.5. [§1910.261(a)(2)]

(3) General incorporation of standards. Establishments subject to this section shall comply with the following standards of the American National Standards Institute, which are incorporated by reference as specified in §1910.6: [§1910.261(a)(3)] (i) Practice for Industrial Lighting, A11.1 — 1965 (R-1970). [§1910.261(a)(3)(i)]

(ii) Scheme for the Identification of Piping Systems, A13.1 — 1956. [§1910.261(a)(3)(ii)] (iii) Safety Code for Elevators, Dumbwaiters, and Moving Walks, A17.1 — 1965, including Supplements A17.1a — 1967, A17.1b — 1968, A17.1c — 1969, and A17.1d — 1970. [§1910.261(a)(3)(iii)]

[§1910.261(a)(3)(vii)]

(viii) Prevention of Sulfur Fires and Explosions, Z12.12 — 1968. [§1910.261(a)(3)(viii)] (ix) Installation of Blower and Exhaust Systems for Dust, Stock, and Vapor Removal or Conveying, Z33.1 — 1961. [§1910.261(a)(3)(ix)]

(4) Other standards. The following standards, which are incorporated by reference as specified in §1910.6, shall be considered standards under this section: [§1910.261(a)(4)] (i) ASME Boiler and Pressure Vessel Code, Section VIII, Unfired Pressure Vessels, including addenda 1969. [§1910.261(a)(4)(i)] (ii)  Building Exits Code for Life Safety from Fire, NFPA 101 — 1970. [§1910.261(a)(4)(ii)] (iii) Safety in the Handling and Use of Explosives, IME Pamphlet No. 17, July 1960, Institute of Makers of Explosives. [§1910.261(a)(4)(iii)]

(b) Safe practices — [§1910.261(b)] (1)  Lockouts. Devices such as padlocks shall be provided for locking out the source of power at the main disconnect switch.

Before any maintenance, inspection, cleaning, adjusting, or servicing of equipment (electrical, mechanical, or other) that requires entrance into or close contact with the machinery or equipment, the main power disconnect switch or valve, or both, controlling its source of power or flow of material, shall be locked out or blocked off with padlock, blank flange, or similar device. [§1910.261(b)(1)] (2) Emergency lighting. Emergency lighting shall be provided wherever it is necessary for employees to remain at their machines or stations to shut down equipment in case of power failure. Emergency lighting shall be provided at stairways and passageways or aisleways used by employees for emergency exit in case of power failure. Emergency lighting shall be provided in all plant first aid and medical facilities. [§1910.261(b)(2)] (c)  Handling and storage of pulpwood and pulp chips — [§1910.261(c)]

(1) Handling pulpwood with forklift trucks. Where large forklift trucks, or lift trucks with clam-jaws, are used in the yard, the operator's enclosed cab shall be provided with an escape hatch, whenever the hydraulic arm blocks escape through the side doors. [§1910.261(c)(1)] (2) Handling pulpwood with cranes or stackers. [§1910.261(c)(2)] (i) Where locomotive cranes are used for loading or unloading pulpwood, the pulpwood shall be piled so as to allow a clearance of not less than 24 inches between the pile and the end of the cab of any locomotive crane in use, when the cab is turned in any working position. [§1910.261(c)(2)(i)]

(ii) The minimum distance of the pulpwood pile from the centerline of a standard-gage track shall be maintained at not less than 81⁄2 feet. [§1910.261(c)(2)(ii)] (iii) Logs shall be piled in an orderly and stable manner, with no projection into walkways or roadways. [§1910.261(c)(2)(iii)] (iv) Railroad cars shall not be spotted on tracks adjacent to the locomotive cranes unless a 24-inch clearance is maintained, as required in paragraph (c)(2)(i) of this section. [§1910.261(c)(2)(iv)]

(v) The handling and storage of other materials shall conform to paragraphs (c)(2)(i) and (ii) of this section with respect to clearance. [§1910.261(c)(2)(v)] (vi) No person shall be permitted to walk beneath a suspended load, bucket, or hook. [§1910.261(c)(2)(vi)] (3) Handling pulpwood from ships. [§1910.261(c)(3)] (i) [Reserved] [§1910.261(c)(3)(i)] (ii) The hatch tender shall be required to signal the hoisting engineer to move the load only after the men working in the hold are in the clear. [§1910.261(c)(3)(ii)] (iii) The air in the ship's hold, tanks, or closed vessels shall be tested for oxygen deficiency and for both toxic and explosive gases and vapors. [§1910.261(c)(3)(iii)] (4) Handling pulpwood from flatcars and all other railway cars. [§1910.261(c)(4)]

(i) Railroad flatcars for the conveyance of pulpwood loaded parallel to the length of the car shall be equipped with safetystake pockets. [§1910.261(c)(4)(i)] (ii) Where pulpwood is loaded crosswise on a flatcar sufficient stakes of sizes not smaller than 4 by 4 inches shall be used to prevent the load from shifting. [§1910.261(c)(4)(ii)] (iii) When it is necessary to cut stakes, those on the unloading side should be partially cut through first, and then the binder wires cut on the opposite side. Wire cutters equipped with long extension handles shall be used. No person shall be permitted along the dumping side of the car after the stakes have been cut. [§1910.261(c)(4)(iii)] (iv) When steel straps without stakes are used, the steel straps shall be cut from a safe area to prevent employees from being struck by the falling logs. [§1910.261(c)(4)(iv)] (v) Flatcars and all other cars shall be chocked during unloading. Where equipment is not provided with hand brakes, rail clamping chocks shall be used. [§1910.261(c)(4)(v)] (vi) A derail shall be used to prevent movement of other rail equipment into cars where persons are working. [§1910.261(c)(4)(vi)]

(5) Handling pulpwood from trucks. [§1910.261(c)(5)] (i) Cutting of stakes and binder wires shall be done in accordance with paragraph (c)(4)(iii) of this section. [§1910.261(c)(5)(i)]

(ii) Where binder chain and steel stakes are used, the binder chains shall be released and the stakes tripped from the opposite side of the load spillage. [§1910.261(c)(5)(ii)] (iii) Where binder chains and crane slings are used, the crane slings shall be attached and taut before the binder chains are released. The hooker shall see that the helper is clear before signaling for the movement of the load. [§1910.261(c)(5)(iii)] (6) Handling pulp chips from railway cars. All cars shall be securely fastened in place and all employees in the clear before dumping is started. [§1910.261(c)(6)] (7) Handling pulp chips from trucks and trailers. All trucks and trailers shall be securely fastened in place and all employees in the clear before dumping is started. [§1910.261(c)(7)] (8) Cranes. [§1910.261(c)(8)] (i) [Reserved] [§1910.261(c)(8)(i)] (ii) A safety device such as a heavy chain or cable at least equal in strength to the lifting cables shall be fastened to the boom and to the frame of the boom crane (if it is other than locomotive) at the base. Alternatively, a telescoping safety device shall be fastened to the boom and to the cab frame, so as to prevent the boom from snapping back over the cab in the event of lifting cable breakage. [§1910.261(c)(8)(ii)] (iii) A crane shall not be operated where any part thereof may come within 10 feet of overhead powerlines (or other overhead obstructions) unless the powerlines have been deenergized. The boom shall be painted bright yellow from and including the head sheave to a point 6 feet down the boom towards the cab. [§1910.261(c)(8)(iii)] (iv) Standard signals for the operation of cranes shall be established for all movements of the crane, in accordance with American National Standards B30.2 — 1943 (reaffirmed 1968) and B30.2.0 — 1967. [§1910.261(c)(8)(iv)]

45

R Special Industries

(iv) Practice for the Inspection of Elevators (Inspector's Manual), A17.2 — 1960, including Suppelements A17.2a — 1965 and A17.2b — 1967. [§1910.261(a)(3)(iv)] (v)  Safety Code for Conveyors, Cableways, and Related Equipment, B20.1 — 1957. [§1910.261(a)(3)(v)] (vi) Power Piping, B31.1.0 — 1967 and addenda B31.10a — 1969. Fuel Gas Piping, B31.2 — 1968. [§1910.261(a)(3)(vi)] (vii) Identification of Gas-Mask Canisters, K13.1 — 1967.

§1910.261(c)

§1910.261

Subpart R – Special Industries

(v) Only one member of the crew shall be authorized to give signals to the crane operator. [§1910.261(c)(8)(v)] (vi) All cranes shall be equipped with a suitable warning device such as a horn or whistle. [§1910.261(c)(8)(vi)] (vii) A sheave guard shall be provided beneath the head sheave of the boom. [§1910.261(c)(8)(vii)] (9) Traffic warning signs or signals. [§1910.261(c)(9)] (i) A flagman shall direct the movement of cranes or locomotives being moved across railroad tracks or roads, and at any points where the vision of the operator is restricted. The flagman must always remain in sight of the operator when the crane or locomotive is in motion. The blue flag policy shall be used to mark stationary cars day and night. This policy shall include marking the track in advance of the spotted cars (flag for daytime, light for darkness). [§1910.261(c)(9)(i)] (ii) After cars are spotted for loading or unloading, warning flags or signs shall be placed in the center of the track at least 50 feet away from the cars and a derail set to protect workmen in the car. [§1910.261(c)(9)(ii)] (10) Illumination. Artificial illumination shall be provided when loading or unloading is performed after dark, in accordance with American National Standard A11.1 — 1965 (R — 1970). [§1910.261(c)(10)]

(11) [Reserved] [§1910.261(c)(11)] (12) Barking devices. When barking drums are employed in the yard, the requirements of paragraph (e)(12) of this section shall apply. [§1910.261(c)(12)] (13) Hand tools. Handles of wood hooks shall be locked to the shank to prevent them from rotating. [§1910.261(c)(13)] (14) Removal of pulpwood. [§1910.261(c)(14)] (i) The ends of a woodpile shall be properly sloped and crosstiered into the pile. Upright poles shall not be used at the ends of woodpiles. To knock down wood from the woodpile, mechanical equipment shall be used to permit employees to keep in the clear of loosened wood. [§1910.261(c)(14)(i)] (ii) If dynamite is used to loosen the pile, only authorized personnel shall be permitted to handle and discharge the explosive. An electric detonator is preferable for firing; if a fuse is used, it shall be an approved safety fuse with a burning rate of not less than 120 seconds per yard and a minimum length of 3 feet, in accordance with Safety in the Handling and Use of Explosives, IME Pamphlet No. 17, July 1960. [§1910.261(c)(14)(ii)] (15) Belt conveyors. [§1910.261(c)(15)] (i) The sides of the conveyor shall be constructed so that the wood will not fall off. [§1910.261(c)(15)(i)] (ii) Where conveyors cross passageways or roadways, a horizontal platform shall be provided under the conveyor, extended out from the sides of the conveyor a distance equal to 11⁄2 times the length of the wood handled. The platform shall extend the width of the road plus 2 feet (61 cm) on each side, and shall be kept free of wood and rubbish. The edges of the platform shall be provided with toeboards or other protection that meet the requirements of subpart D of this part, to prevent wood from falling. [§1910.261(c)(15)(ii)]

(iii) All conveyors for pulpwood shall have the inrunning nips between chain and sprockets guarded; also, turning drums shall be guarded. [§1910.261(c)(15)(iii)] (iv) Every belt conveyor shall have an emergency stop cable extending the length of the conveyor so that it may be stopped from any location along the line, or conveniently located stop buttons within 10 feet of each work station, in accordance with American National Standard B20.1 — 1957. [§1910.261(c)(15)(iv)] (16) Signs. When conveyors cross walkways or roadways in the yards, the employer must erect signs reading "Danger — Overhead Conveyor” or an equivalent warning, in accordance with ANSI Z35.1-1968 or ANSI Z535.2-2011, incorporated by reference in §1910.6. [§1910.261(c)(16)] (d) Handling and storage of raw materials other than pulpwood or pulp chips — [§1910.261(d)] (1) Personal protective equipment. Whenever possible, all dust, fumes, and gases incident to handling materials shall be controlled at the source, in accordance with American National Standard Z9.2 — 1960. Where control at the source is not possible, respirators with goggles or protective masks shall be provided, and employees shall wear them when handling alum, clay, soda ash, lime, bleach powder, sulfur, chlorine, and similar materials, and when opening rag bales. [§1910.261(d)(1)]

46

(2) Clearance. [§1910.261(d)(2)] (i) When materials are being piled inside a building and upon platforms, an aisle clearance at least 3 feet greater than the widest truck in use shall be provided. [§1910.261(d)(2)(i)] (ii) Baled paper and rags stored inside a building shall not be piled closer than 18 inches to walls, partitions, or sprinkler heads. [§1910.261(d)(2)(ii)] (3) Piling and unpiling pulp. [§1910.261(d)(3)] (i) Piles of wet lap pulp (unless palletized) shall be stepped back one-half the width of the sheet for each 8 feet of pile height.

Sheets of pulp shall be interlapped to make the pile secure.

Pulp shall not be piled over pipelines to jeopardize pipes, or so as to cause overloading of floors, or to within 18 inches below sprinkler heads. [§1910.261(d)(3)(i)] (ii) Piles of pulp shall not be undermined when being unpiled. [§1910.261(d)(3)(ii)]

(iii) Floor capacities shall be clearly marked on all floors. [§1910.261(d)(3)(iii)]

(4) (i) [Reserved] [§1910.261(d)(4)(i)] (ii) Where rolls are pyramided two or more high, chocks shall be installed between each roll on the floor and at every row.

Where pulp and paper rolls are stored on smooth floors in processing areas, rubber chocks with wooden core shall be used. [§1910.261(d)(4)(ii)] (iii) When rolls are decked two or more high, the bottom rolls shall be chocked on each side to prevent shifting in either direction. [§1910.261(d)(4)(iii)] (e) Preparing pulpwood — [§1910.261(e)] (1) Gang and slasher saws. A guard shall be provided in front of all gang and slasher saws to protect workers from wood thrown by saws. A guard shall be placed over tail sprockets. [§1910.261(e)(1)]

(2) Slasher tables. Saws shall be stopped and power switches shall be locked out and tagged whenever it is necessary for any person to be on the slasher table. [§1910.261(e)(2)] (3) [Reserved] [§1910.261(e)(3)] (4) Runway to the jack ladder. The runway from the pond or unloading dock to the table shall be protected with standard handrails and toeboards. Inclined portions shall have cleats or equivalent nonslip surfacing that complies with subpart D of this part. Protective equipment shall be provided for persons working over water. [§1910.261(e)(4)]

(5) Guards below table. Where not protected by the frame of the machine, the underside of the slasher saws shall be enclosed with guards. [§1910.261(e)(5)] (6) Conveyors. The requirements of paragraph (c)(15)(iv) of this section shall apply. [§1910.261(e)(6)] (7) [Reserved] [§1910.261(e)(7)] (8) Barker feed. Each barker shall be equipped with a feed and turnover device which will make it unnecessary for the operator to hold a bolt or log by hand during the barking operation.

Eye, ear, and head protection shall be provided for the operator, in accordance with paragraph (b)(2) of this section. [§1910.261(e)(8)]

(9) [Reserved] [§1910.261(e)(9)] (10) Stops. All control devices shall be locked out and tagged when knives are being changed. [§1910.261(e)(10)] (11) Speed governor. Water wheels, when directly connected to barker disks or grinders, shall be provided with speed governors, if operated with gate wide open. [§1910.261(e)(11)] (12) Continuous barking drums. [§1910.261(e)(12)] (i) When platforms or floors allow access to the sides of the drums, a standard railing shall be constructed around the drums. When two or more drums are arranged side by side, proper walkways with standard handrails shall be provided between each set, in accordance with the requirements of 29 CFR 1910.23, Guarding floor and wall openings and holes. [§1910.261(e)(12)(i)] (ii) Sprockets and chains, gears, and trunnions shall have standard guards, in accordance with the requirements of 29 CFR 1910.219, Mechanical power-transmission apparatus. [§1910.261(e)(12)(ii)]

(iii) Whenever it becomes necessary for a workman to go within a drum, the driving mechanism shall be locked and tagged, at the main disconnect switch, in accordance with paragraph (b)(1) of this section. [§1910.261(e)(12)(iii)] (13) Intermittent barking drums. In addition to motor switch, clutch, belt shifter, or other power disconnecting device, intermittent barking drums shall be equipped with a device which may be locked to prevent the drum from moving while it is being emptied or filled. [§1910.261(e)(13)]

Pulp, paper, and paperboard mills (14) Hydraulic barkers. Hydraulic barkers shall be enclosed with strong baffles at the inlet and the outlet. The operator shall be protected by at least five-ply laminated glass. [§1910.261(e)(14)] (15) Splitter block. The block upon or against which the wood is rested shall have a corrugated surface or other means provided that the wood will not slip. Wood to be split, and also the splitting block, shall be free of ice, snow, or chips. The operator shall be provided with eye and foot protection. A clear and unobstructed view shall be maintained between equipment and workers around the block and the workers' help area. [§1910.261(e)(15)]

(16) Power control. Power for the operation of the splitter shall be controlled by a clutch or equivalent device. [§1910.261(e)(16)] (17) Knot cleaners. The operators of knot cleaners of the woodpecker type shall wear eye protection equipment. [§1910.261(e)(17)]

[§1910.261(f)(1)(ii)]

(2) Shredders, cutters, and dusters. [§1910.261(f)(2)] (i) Rotating heads or cylinders shall be completely enclosed except for an opening at the feed side sufficient to permit only the entry of stock. The enclosure shall extend over the top of the feed rolls. It shall be constructed either of solid material or with mesh or openings not exceeding one-half inch and substantial enough to contain flying particles and prevent accidental contact with moving parts. The enclosure shall be bolted or locked into place. [§1910.261(f)(2)(i)] (ii) A smooth-pivoted idler roll resting on the stock or feed table shall be provided in front of feed rolls except when arrangements prevent the operator from standing closer than 36 inches to any part of the feed rolls. [§1910.261(f)(2)(ii)] (iii) Any manually fed cutter, shredder, or duster shall be provided with an idler roll as per subdivision (ii) of this subparagraph or the operator shall use special hand-feeding tools. [§1910.261(f)(2)(iii)]

(iv) Hoods of cutters, shredders, and dusters shall have exhaust ventilation, in accordance with American National Standard Z9.2 — 1960. [§1910.261(f)(2)(iv)] (3) Blowers. [§1910.261(f)(3)] (i) Blowers used for transporting rags shall be provided with feed hoppers having outer edges located not less than 48 inches from the fan. [§1910.261(f)(3)(i)] (ii) The arrangement of the blower discharge outlets and work areas shall be such as to prevent material from falling on workers. [§1910.261(f)(3)(ii)] (4) Conveyors. Conveyors and conveyor drive belts and pulleys shall be fully enclosed or, if open and within 7 feet of the floor, shall be constructed and guarded in accordance with paragraph (c)(15) of this section and American National Standards B15.1 — 1953 (Reaffirmed 1958) and B20.1 — 1957. [§1910.261(f)(4)]

(5) Dust. Measures for the control of dust shall be provided, in accordance with American National Standards Z33.1 — 1961, Z87.1 — 1968, and Z88.2 — 1969. [§1910.261(f)(5)] (6) Rag cookers. [§1910.261(f)(6)] (i) When cleaning, inspection, or other work requires that persons enter rag cookers, all steam and water valves, or other control devices, shall be locked and tagged in the closed or "off” position. Blank flanging of pipelines is acceptable in place of closed and locked valves. [§1910.261(f)(6)(i)]

(ii) When cleaning, inspection, or other work requires that persons must enter the cooker, one person shall be stationed outside in a position to observe and assist in case of emergency, in accordance with paragraph (b)(5) of this section. [§1910.261(f)(6)(ii)]

(iii) [Reserved] [§1910.261(f)(6)(iii)] (iv) Rag cookers shall be provided with safety valves in accordance with the ASME Boiler and Pressure Vessel Code, Section VIII, Unfired Pressure Vessels — 1968, with Addenda. [§1910.261(f)(6)(iv)]

(g) Chemical processes of making pulp — [§1910.261(g)] (1) Sulfur burners. [§1910.261(g)(1)] (i) Sulfur-burner houses shall be safely and adequately ventilated, and every precaution shall be taken to guard against dust explosion hazards and fires, in accordance with American National Standards Z9.2 — 1960 and Z12.12 — 1968. [§1910.261(g)(1)(i)]

(ii) Nonsparking tools and equipment shall be used in handling dry sulfur. [§1910.261(g)(1)(ii)] (iii) Sulfur storage bins shall be kept free of sulfur dust accumulation, in accordance with American National Standard Z9.2 — 1960. [§1910.261(g)(1)(iii)] (iv) Sulfur-melting equipment shall not be located in the burner room. [§1910.261(g)(1)(iv)] (2) Protection for employees (acid plants). [§1910.261(g)(2)] (i) Supplied air respirators shall be strategically located for emergency and rescue use. [§1910.261(g)(2)(i)] (ii) The worker shall be provided with eye protection, a supplied air respirator and a personal fall protection system that meets the requirements of subpart I of this part, during inspection, repairs or maintenance of acid towers. The line shall be extended to an attendant stationed outside the tower opening. [§1910.261(g)(2)(ii)]

(3) Acid tower structure. Outside elevators shall be inspected daily during winter months when ice materially affects safety. Elevators, runways, stairs, etc., for the acid tower shall be inspected monthly for defects that may occur because of exposure to acid or corrosive gases. [§1910.261(g)(3)] (4) Tanks (acid). [§1910.261(g)(4)] (i) Tanks shall be free of acid and shall be washed out with water, and fresh air shall be blown into them before allowing men to enter. Men entering the tanks shall be provided with supplied air respirators, lifebelts, and attached lifelines. [§1910.261(g)(4)(i)] (ii) A man shall be stationed outside to summon assistance if necessary. All intake valves to a tank shall be blanked off or disconnected. [§1910.261(g)(4)(ii)] (5) Clothing. Where lime slaking takes place, employees shall be provided with rubber boots, rubber gloves, protective aprons, and eye protection. A deluge shower and eye fountain shall be provided to flush the skin and eyes to counteract lime or acid burns. [§1910.261(g)(5)] (6) Lead burning. When lead burning is being done within tanks, fresh air shall be forced into the tanks so that fresh air will reach the face of the worker first and the direction of the current will never be from the source of the fumes toward the face of the workers. Supplied air respirators (constant-flow type) shall be provided. [§1910.261(g)(6)] (7) Hoops for acid storage tanks. Hoops of tanks shall be made of rods rather than flat strips and shall be safely maintained by scheduled inspections. [§1910.261(g)(7)] (8) Chip and sawdust bins. Steam or compressed-air lances, or other facilities, shall be used for breaking down the arches caused by jamming in chip lofts. No worker shall be permitted to enter a bin unless provided with a safety belt, with line attached, and an attendant stationed at the bin to summon assistance. [§1910.261(g)(8)]

(9)  Exits (digester building). At least one unobstructed exit at each end of the room shall be provided on each floor of a digester building. [§1910.261(g)(9)] (10) Gas masks (digester building). Gas masks must be available, and they must furnish adequate protection against sulfurous acid and chlorine gases and be inspected and repaired in accordance with 29 CFR 1910.134. [§1910.261(g)(10)] (11) Elevators. [§1910.261(g)(11)] (i) Elevators shall be constructed in accordance with American National Standard A17.1 — 1965. [§1910.261(g)(11)(i)] (ii) Elevators shall be equipped with gas masks for the maximum number of passengers. [§1910.261(g)(11)(ii)] (iii) Elevators shall be equipped with an alarm system to advise of failure. [§1910.261(g)(11)(iii)]

47

R Special Industries

(18) Chipper spout. The feed system to the chipper spout shall be arranged in such a way that the operator does not stand in a direct line with the chipper spout. All chipper spouts shall be enclosed to a height of at least 42 inches from the floor or operator's platform. When other protection is not sufficient, the operator shall wear a safety belt line. The safety belt line shall be fastened in such a manner as to make it impossible for the operator to fall into the throat of the chipper. Ear protection equipment shall be worn by the operator and others in the immediate area if there is any possibility that the noise level may be harmful (see §1910.95). [§1910.261(e)(18)] (19) Carriers for knives. Carriers shall be provided and used for transportation of knives. [§1910.261(e)(19)] (f) Rag and old paper preparation — [§1910.261(f)] (1) Ripping and trimming tools. [§1910.261(f)(1)] (i) Hand knives and scissors shall have blunt points, shall be fastened to the table with chain or thong, and shall not be carried on the person but placed safely in racks or sheaths when not in use. [§1910.261(f)(1)(i)] (ii) Hand knives and sharpening steels shall be provided with guards at the junction of the handle and the blade.

§1910.261(g)

§1910.261

Subpart R – Special Industries

(12) Blowoff valves and piping. [§1910.261(g)(12)] (i) The blowoff valve of a digester shall be arranged so as to be operated from another room, remote from safety valves. [§1910.261(g)(12)(i)]

(ii)  Through bolts instead of cap bolts shall be used on all digester pipings. [§1910.261(g)(12)(ii)] (iii) Heavy duty pipe, valves, and fittings shall be used between the digester and blow pit. These valves, fittings, and pipes shall be inspected at least semiannually to determine the degree of deterioration. [§1910.261(g)(12)(iii)] (iv)  Digester blow valves shall be pinned or locked in closed position throughout the entire cooking period. [§1910.261(g)(12)(iv)]

(13) Blow pits and blow tanks. [§1910.261(g)(13)] (i) Blow-pit openings preferably shall be on the side of the pit instead of on the top. Openings shall be as small as possible when located on top, and shall be protected in accordance with subpart D of this part. [§1910.261(g)(13)(i)] (ii) A specially constructed ladder shall be used for access to blow pits, to be constructed so that the door of the blow pit cannot be closed when the ladder is in place; other means shall be provided to prevent the closing of the pit door when anyone is in the pit. [§1910.261(g)(13)(ii)] (iii) A signaling device shall be installed in the digester and blow-pit rooms and chip bins to be operated as a warning before and while digesters are being blown. [§1910.261(g)(13)(iii)]

(iv) Blow-pit hoops shall be maintained in a safe condition. [§1910.261(g)(13)(iv)]

(14) Blowing digester. [§1910.261(g)(14)] (i) Blowoff valves shall be opened slowly. [§1910.261(g)(14)(i)] (ii) After the digester has started to be blown, the blowoff valve shall be left open, and the hand plate shall not be removed until the digester cook signals the blow-pit man that the blow is completed. Whenever it becomes necessary to remove the hand plate to clear stock, operators shall wear eye protection equipment and protective clothing to guard against burns from hot stock. [§1910.261(g)(14)(ii)] (iii) Means shall be provided whereby the digester cook shall signal the man in the chip bin before starting to load the digester. [§1910.261(g)(14)(iii)] (15) Inspecting and repairing digester. [§1910.261(g)(15)] (i) Valves controlling lines leading into a digester shall be locked out and tagged. The keys to the locks shall be in the possession of a person or persons doing the inspecting or making repairs. [§1910.261(g)(15)(i)] (ii) Fresh air shall be blown into the digester constantly while workmen are inside. Supplied air respirators shall be available in the event the fresh air supply fails or is inadequate. [§1910.261(g)(15)(ii)]

(iii) No inspector shall enter a digester unless a lifeline is securely fastened to his body by means of a safety belt and at least one other experienced employee is stationed outside the digester to handle the line and to summon assistance. All ladders and lifelines shall be inspected before each use. [§1910.261(g)(15)(iii)] (iv) All employees entering digesters for inspection or repair work shall be provided with protective headgear. Eye protection and dust masks shall be provided to workmen while the old brick lining is being removed, in accordance with American National Standards, Z87.1 — 1968, Z88.2 — 1969, and Z99.1 — 1969. [§1910.261(g)(15)(iv)] (16) Pressure tanks-accumulators (acid). [§1910.261(g)(16)] (i) Safety regulations governing inspection and repairing of pressure tanks-accumulators (acid) shall be the same as those specified in subparagraph (15) of this paragraph. [§1910.261(g)(16)(i)]

(ii) The pressure tanks-accumulators shall be inspected twice annually. (See the ASME Boiler and Pressure Vessel Code, Section VIII, Unfired Pressure Vessels — 1968, with Addenda.) [§1910.261(g)(16)(ii)] (17) Pressure vessels (safety devices). [§1910.261(g)(17)] (i) A safety valve shall be installed in a separate line from each pressure vessel; no hand valve shall be installed between this safety valve and the pressure vessel. Safety valves shall be checked between each cook to be sure they have not become plugged or corroded to the point of being inoperative. (See the ASME Boiler and Pressure Vessel Code, Section VIII, Unfired Pressure Vessels — 1968, with Addenda.) [§1910.261(g)(17)(i)]

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(ii) All safety devices shall conform to Paragraph U-2 in the ASME Boiler and Pressure Vessel Code, Section VIII, Unfired Pressure Vessels — 1968, with Addenda. [§1910.261(g)(17)(ii)]

(18) Miscellaneous. Insofar as the processes of the sulfate and soda operations are similar to those of the sulfite processes, the standard of paragraphs (g)(1) through (17) of this section shall apply. [§1910.261(g)(18)] (i) Quick operating showers, bubblers, etc., shall be available for emergency use in case of caustic soda burns. [§1910.261(g)(18)(i)] (ii) Rotary tenders, smelter operators, and those cleaning smelt spouts shall be provided with eye protection equipment (fitted with lenses that filter out the harmful rays emanating from the light source) when actively engaged in their duties, in accordance with American National Standard Z87.1 — 1968. [§1910.261(g)(18)(ii)]

(iii) Heavy-duty pipe, valves, and fittings shall be used between digester and blow pit. These shall be inspected at least semiannually to determine the degree of deterioration and repaired or replaced when necessary, in accordance with American National Standards B31.1 — 1955, B31.1a — 1963, B31.1.0 — 1967, and B31.2 — 1968. [§1910.261(g)(18)(iii)] (iv) Smelt-dissolving tanks shall be covered and the cover kept closed, except when samples are being taken. [§1910.261(g)(18)(iv)]

(v) Smelt tanks shall be provided with vent stacks and explosion doors, in accordance with American National Standard Z9.1 — 1951. [§1910.261(g)(18)(v)] (19) Blow lines. [§1910.261(g)(19)] (i) — (ii) [Reserved] [§1910.261(g)(19)(i)] (iii) When blow lines from more than one digester lead into one pipe, the cock or valve of the blow line from the tank being inspected or repaired shall be locked or tagged out, or the line shall be disconnected and blocked off. [§1910.261(g)(19)(iii)] (20) Furnace room. Exhaust ventilation shall be provided where niter cake is fed into a rotary furnace and shall be so designed and maintained as to keep the concentration of hydrogen sulfide gas below the parts per million listed in §1910.1000. [§1910.261(g)(20)]

(21) Inspection and repair of tanks. All piping leading to tanks shall be blanked off or valved and locked or tagged. Any lines to sewers shall be blanked off to protect workers from air contaminants. [§1910.261(g)(21)]

(22) Welding. Welding on blow tanks, accumulator tanks, or any other vessels where turpentine vapor or other combustible vapor could gather shall be done only after the vessel has been completely purged of fumes. Fresh air shall be supplied workers inside of vessels. [§1910.261(g)(22)] (23) Turpentine systems and storage tanks. Nonsparking tools and ground hose shall be used when pumping out the tank. The tank shall be surrounded by a berm or moat. [§1910.261(g)(23)] (h) Bleaching — [§1910.261(h)] (1) Bleaching engines. Bleaching engines, except the Bellmer type, shall be completely covered on the top, with the exception of one small opening large enough to allow filling, but too small to admit an employee. Platforms leading from one engine to another shall have standard guardrails that meet the requirements in subpart D of this part. [§1910.261(h)(1)] (2) Bleach mixing rooms. [§1910.261(h)(2)] (i) The room in which the bleach powder is mixed shall be provided with adequate exhaust ventilation, located at the floor level, in accordance with American National Standard Z9.1 — 1951. [§1910.261(h)(2)(i)] (ii) Chlorine gas shall be carried away from the work place and breathing area by an exhaust system. The gas shall be rendered neutral or harmless before being discharged into the atmosphere. The requirements of American National Standard Z9.2 — 1960 shall apply to this subdivision. [§1910.261(h)(2)(ii)]

(iii) For emergency and rescue operations, the employer must provide employees with self-contained breathing apparatuses or supplied-air respirators, and ensure that employees use these respirators, in accordance with the requirements of 29 CFR 1910.134. [§1910.261(h)(2)(iii)] (3) Liquid chlorine. [§1910.261(h)(3)] (i) Tanks of liquid chlorine shall be stored in an adequately ventilated unoccupied room, where their possible leakage cannot affect workers. [§1910.261(h)(3)(i)] (ii) Gas masks capable of absorbing chlorine shall be supplied, conveniently placed, and regularly inspected, and workers who may be exposed to chlorine gas shall be instructed in their use. [§1910.261(h)(3)(ii)]

Sawmills

(iii) Floor maintenance. The flooring of buildings, docks, and passageways shall be kept in good repair. When a hazardous condition develops that cannot be immediately repaired, the area shall be guarded until adequate repairs are made. [§1910.265(c)(3)(iii)] (iv) Nonslip floors. Floors, footwalks, and passageways in the work area around machines or other places where a person is required to stand or walk shall be provided with effective means to minimize slipping. [§1910.265(c)(3)(iv)] (4) Walkways, docks, and platforms. [§1910.265(c)(4)] (i) Width. Walkways, docks, and platforms shall be of sufficient width to provide adequate passage and working areas. [§1910.265(c)(4)(i)]

(ii) Maintenance. Walkways shall be evenly floored and kept in good repair. [§1910.265(c)(4)(ii)] (iii) Docks. Docks and runways used for the operation of lift trucks and other vehicles shall have a substantial guard or shear timber except where loading and unloading are being performed. [§1910.265(c)(4)(iii)] (iv) Elevated walks. All elevated walks, runways, or platforms, if 4 feet or more from the floor level, shall be provided with a standard railing except on loading or unloading sides of platforms. If height exceeds 6 feet, a standard toe board also shall be provided to prevent material from rolling or falling off. [§1910.265(c)(4)(iv)] (v) Elevated platforms. Where elevated platforms are used routinely on a daily basis, they shall be equipped with stairways or fixed ladders that comply with subpart D of this part. [§1910.265(c)(4)(v)] (vi) Hazardous locations. Where required, walkways and stairways with standard handrails shall be provided in elevated and hazardous locations. Where such passageways are over walkways or work areas, standard toe boards shall be provided. [§1910.265(c)(4)(vi)] (5) Stairways. [§1910.265(c)(5)] (i) Construction. Stairways shall be constructed in accordance with subpart D of this part. [§1910.265(c)(5)(i)] (ii) Handrails. Stairways shall be provided with a standard handrail on at least one side or on any open side. Where stairs are more than four feet wide there shall be a standard handrail at each side, and where more than eight feet wide, a third standard handrail shall be erected in the center of the stairway. [§1910.265(c)(5)(ii)] (iii) Lighting. All stairways shall be adequately lighted as prescribed in paragraph (c)(9) of this section. [§1910.265(c)(5)(iii)] (6) Emergency exits including doors and fire escapes. [§1910.265(c)(6)] (i) Opening. Doors shall not open directly on or block a flight of stairs, and shall swing in the direction of exit travel. [§1910.265(c)(6)(i)]

(ii) Identification. Exits shall be located and identified in a manner that affords ready exit from all work areas. [§1910.265(c)(6)(ii)] (iii) Swinging doors. All swinging doors shall be provided with windows; with one window for each section of double swinging doors. Such windows shall be of shatterproof or safety glass unless otherwise protected against breakage. [§1910.265(c)(6)(iii)]

(iv) Sliding doors. Where sliding doors are used as exits, an inner door shall be cut inside each of the main doors and arranged to open outward. [§1910.265(c)(6)(iv)] (v) Barriers and warning signs. Where a doorway opens upon a railroad track or upon a tramway or dock over which vehicles travel, a barrier or other warning device shall be placed to prevent workmen from stepping into moving traffic. [§1910.265(c)(6)(v)] (7) Air requirements. Ventilation shall be provided to supply adequate fresh healthful air to rooms, buildings, and work areas. [§1910.265(c)(7)]

(8) Vats and tanks. All open vats and tanks into which workmen could fall shall be guarded. [§1910.265(c)(8)] (9) Lighting. [§1910.265(c)(9)] (i) Adequacy. Illumination shall be provided and designed to supply adequate general and local lighting to rooms, buildings, and work areas during the time of use. [§1910.265(c)(9)(i)] (ii) Effectiveness. Factors upon which the adequacy and effectiveness of illumination will be judged, include the following: [§1910.265(c)(9)(ii)]

[a] The quantity of light in foot-candle intensity shall be sufficient for the work being done. [§1910.265(c)(9)(ii)[a]] [b] The quality of the light shall be such that it is free from glare, and has correct direction, diffusion, and distribution. [§1910.265(c)(9)(ii)[b]]

[c] Shadows and extreme contrasts shall be avoided or kept to a minimum. [§1910.265(c)(9)(ii)[c]]

59

R Special Industries

(21) Kiln tender. The term kiln tender means the operator of a kiln.

(22) Lift truck. The term lift truck means an industrial truck used for lateral transportation and equipped with a power-operated lifting device, usually in the form of forks, for piling or unpiling lumber units or packages.

(23) Live rolls. The term live rolls means cylinders of wood or metal mounted on horizontal axes and rotated by power, which are used to convey slabs, lumber, and other wood products.

(24) Loading boom. The term loading boom means any structure projecting from a pivot point to guide a log when lifted.

(25) Log deck. The term Log deck means a platform in the sawmill on which the logs remain until needed for sawing.

(26) Lumber hauling truck. The term lumber hauling truck means an industrial truck, other than a lift truck or a carrier, used for the transport of lumber.

(27) Log haul. The term log haul means a conveyor for transferring logs to mill.

(28) Package. The term package means a unit of lumber.

(29) Peavy. The term peavy means a stout wooden handle fitted with a spike and hook and used for rolling logs.

(30) Pike pole. The term pike pole means a long pole whose end is shod with a sharp pointed spike.

(31) Pitman rod. The term pitman rod means connecting rod.

(32) Resaw. The term resaw means band, circular, or sash gang saws used to break down slabs, cants, or flitches into lumber.

(33) Running line. The term running line means any moving rope as distinguished from a stationary rope such as a guyline.

(34) Safety factor. The term safety factor means a calculated reduction factor which may be applied to laboratory test values to obtain safe working stresses for wooden beams and other mechanical members; ratio of breaking load to safe load.

(35) Saw guide. The term saw guide means a device for steadying a circular or bandsaw.

(36) Setwork. The term setwork means a mechanism on a sawmill carriage which enables an operator to move the log into position for another cut.

(37) Sorting gaps. The term sorting gaps means the areas on a log pond enclosed by boom sticks into which logs are sorted.

(38) Spreader wheel. The term spreader wheel means a metal wheel that separates the board from the log in back of circular saws to prevent binding.

(39) Splitter. The term splitter means a knife-type, nonrotating spreader.

(40) Sticker. The term sticker means a strip of wood or other material used to separate layers of lumber.

(41) Stiff boom. The term stiff boom means the anchored, stationary boom sticks which are tied together and on which boom men work.

(42) Swifter. The term swifter is a means of tying boom sticks together to prevent them from spreading while being towed.

(43) Telltale. The term telltale means a device used to serve as a warning for overhead objects.

(44) Top saw. The term top saw means the upper of two circular saws on a head rig, both being on the same husk.

(45) Tramway. The term tramway means a way for trams, usually consisting of parallel tracks laid on wooden beams.

(46) Trestle. The term trestle means a braced framework of timbers, piles or steelwork for carrying a road or railroad over a depression. (c) Building facilities, and isolated equipment. [§1910.265(c)] (1) Safety factor. All buildings, docks, tramways, walkways, log dumps, and other structures shall be designed, constructed and maintained so as to support the imposed load in accordance with a safety factor. [§1910.265(c)(1)] (2) Work areas. Work areas under mills shall be as evenly surfaced as local conditions permit. They shall be free from unnecessary obstructions and provided with lighting facilities in accordance with American National Standard for Industrial Lighting A11.1 — 1965, which is incorporated by reference as specified in §1910.6. [§1910.265(c)(2)] (3) Floors. Flooring in buildings and on ramps and walkways shall be constructed and installed in accordance with established principles of mechanics and sound engineering practices.

They shall be of adequate strength to support the estimated or actual dead and live loads acting on them with the resultant stress not exceeding the allowable stress for the material being used. [§1910.265(c)(3)] (i) [Reserved] [§1910.265(c)(3)(i)] (ii) Areas beneath floor openings. Areas under floor openings shall, where practical, be fenced off. When this is not practical, they shall be plainly marked and telltales shall be installed to hang over these areas. [§1910.265(c)(3)(ii)]

§1910.265(c)

§1910.265

Subpart R – Special Industries

(10) [Reserved] [§1910.265(c)(10)] (11) Hazard marking. Physical hazard marking shall be as specified in §1910.144 of this part. [§1910.265(c)(11)] (12) [Reserved] [§1910.265(c)(12)] (13) Hydraulic systems. Means shall be provided to block, chain, or otherwise secure equipment normally supported by hydraulic pressure so as to provide for safe maintenance. [§1910.265(c)(13)]

(14) [Reserved] [§1910.265(c)(14)] (15) Gas piping and appliances. All gas piping and appliances shall be installed in accordance with the American National Standard Requirements for the Installation of Gas Appliances and Gas Piping Z21.30 — 1964, which is incorporated by reference as specified in §1910.6. [§1910.265(c)(15)] (16) [Reserved] [§1910.265(c)(16)] (17) [Reserved] [§1910.265(c)(17)] (18)  Conveyors. [§1910.265(c)(18)] (i) Standards. Construction, operation, and maintenance of conveyors shall be in accordance with American National Standard B20.1 — 1957, which is incorporated by reference as specified in §1910.6. [§1910.265(c)(18)(i)] (ii) Guarding. Spiked live rolls shall be guarded. [§1910.265(c)(18)(ii)]

(19) Stationary tramways and trestles. [§1910.265(c)(19)] (i) Foundations and walkways. Tramways and trestles shall have substantial mud sills or foundations which shall be frequently inspected and kept in repair. When vehicles are operated on tramways and trestles which are used for foot passage, traffic shall be controlled or a walkway with standard handrails at the outer edge and shear timber on the inner edge shall be provided. This walkway shall be wide enough to allow adequate clearance to vehicles. When walkways cross over other thoroughfares, they shall be solidly fenced at the outer edge to a height of 42 inches over such thoroughfares. [§1910.265(c)(19)(i)] (ii) Clearance. Stationary tramways and trestles shall have a vertical clearance of 22 feet over railroad rails. When constructed over carrier docks or roads, they shall have a clearance of 6 feet above the driver's foot rest on the carrier, and in no event shall this clearance be less than 12 feet from the roadway. In existing operations where it is impractical to obtain such clearance, telltales, electric signals, signs or other precautionary measures shall be installed. [§1910.265(c)(19)(ii)] (20) Blower, collecting, and exhaust systems. [§1910.265(c)(20)] (i) Design, construction, and maintenance. Blower collecting, and exhaust systems should be designed, constructed, and maintained in accordance with American National Standards Z33.1 — 1961 (For the Installation of Blower and Exhaust Systems for Dust, Stock, and Vapor Removal or Conveying) and Z12.2 — 1962 (R1969) (Code for the Prevention of Dust Explosion in Woodworking and Wood Flour Manufacturing Plants), which are incorporated by reference as specified in §1910.6. [§1910.265(c)(20)(i)] (ii) Collecting systems. All mills containing one or more machines that create dust, shavings, chips, or slivers during a period of time equal to or greater than one-fourth of the working day, shall be equipped with a collecting system. It may be either continuous or automatic, and shall be of sufficient strength and capacity to enable it to remove such refuse from points of operation and immediate vicinities of machines and work areas. [§1910.265(c)(20)(ii)] (iii) Exhaust or conveyor systems. Each woodworking machine that creates dust, shavings, chips, or slivers shall be equipped with an exhaust or conveyor system located and adjusted to remove the maximum amount of refuse from the point of operation and immediate vicinity. [§1910.265(c)(20)(iii)] (iv) [Reserved] [§1910.265(c)(20)(iv)] (v) Dust chambers. Exhaust pipes shall not discharge into an unconfined outside pile if uncontrolled fire or explosion hazards are created. They may empty into settling or dust chambers, designed to prevent the dust or refuse from entering any work area. Such chambers shall be constructed and operated to minimize the danger of fire or dust explosion. [§1910.265(c)(20)(v)] (vi) Hand removal of refuse. Provision for the daily removal of refuse shall be made in all operations not required to have an exhaust system or having refuse too heavy, bulky, or otherwise unsuitable to be handled by the exhaust system. [§1910.265(c)(20)(vi)]

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(21) Chippers. [§1910.265(c)(21)] (i) Whole-log chippers. The feed system to the chipper shall be arranged so the operator does not stand in direct line with the chipper spout (hopper). The chipper spout shall be enclosed to a height of not less than 36 inches from the floor or the operator's platform. A safety belt and lifeline shall be worn by workmen when working at or near the spout unless the spout is guarded. The lifeline shall be short enough to prevent workers from falling into the chipper. [§1910.265(c)(21)(i)]

(ii) Hogs. [§1910.265(c)(21)(ii)] [a] Hog mills shall be so designed and arranged that from no position on the rim of the chute shall the distance to the cutter knives be less than 40 inches. [§1910.265(c)(21)(ii)[a]] [b] Hog feed chutes shall be provided with suitable and approved baffles, which shall minimize material from being thrown from the mill. [§1910.265(c)(21)(ii)[b]] [c] Employees feeding hog mills shall be provided with safety belts and lines unless guarded. [§1910.265(c)(21)(ii)[c]] (22) [Reserved] [§1910.265(c)(22)] (23) Bins, bunkers, hoppers, and fuel houses. [§1910.265(c)(23)] (i) Guarding. Open bins, bunkers, and hoppers whose upper edges extend less than 3 feet above working level shall be equipped with standard handrails and toe boards, or have their tops covered by a substantial grill or grating with openings small enough to prevent a man from falling through. [§1910.265(c)(23)(i)]

(ii) Use of wheeled equipment to load bins. Where automotive or other wheeled equipment is used to move materials into bins, bunkers, and hoppers, adequate guard rails shall be installed along each side of the runway, and a substantial bumper stop provided when necessary. [§1910.265(c)(23)(ii)] (iii) Exits, lighting, and safety devices. Fuel houses and bins shall have adequate exits and lighting, and all necessary safety devices shall be provided and shall be used by persons entering these structures. [§1910.265(c)(23)(iii)] (iv) Walkways. Where needed, fuel houses and bins shall have a standard railed platform or walkway near the top. [§1910.265(c)(23)(iv)]

(24) Ropes, cables, slings, and chains. [§1910.265(c)(24)] (i) Safe usage. Ropes, cables, slings, and chains shall be used in accordance with safe use practices recommended by the manufacturer or within safe limits recommended by the equipment manufacturer when used in conjunction with it. [§1910.265(c)(24)(i)]

(ii) Hooks. No open hook shall be used in rigging to lift any load where there is hazard from relieving the tension on the hook from the load or hook catching or fouling. [§1910.265(c)(24)(ii)] (iii) Work by qualified persons. Installation, inspection, maintenance, repair, and testing of ropes, cables, slings, and chains shall be done only by persons qualified to do such work. [§1910.265(c)(24)(iii)] (iv) Slings. Proper storage shall be provided for slings while not in use. [§1910.265(c)(24)(iv)] (v) Ropes or cables. [§1910.265(c)(24)(v)] [a] Wire rope or cable shall be inspected when installed and once each week thereafter, when in use. It shall be removed from hoisting or load-carrying service when kinked or when one of the following conditions exists: [§1910.265(c)(24)(v)[a]]

[1] When three broken wires are found in one lay of 6 by 6 wire rope. [§1910.265(c)(24)(v)[a][1]] [2] When six broken wires are found in one lay of 6 by 19 wire rope. [§1910.265(c)(24)(v)[a][2]] [3] When nine broken wires are found in one lay of 6 by 37 wire rope. [§1910.265(c)(24)(v)[a][3]] [4] When eight broken wires are found in one lay of 8 by 19 wire rope. [§1910.265(c)(24)(v)[a][4]] [5] When marked corrosion appears. [§1910.265(c)(24)(v)[a][5]] [6] Wire rope of a type not described herein shall be removed from service when 4 percent of the total number of wires composing such rope are found to be broken in one lay. [§1910.265(c)(24)(v)[a][6]] [b] Wire rope removed from service due to defects shall be plainly marked or identified as being unfit for further use on cranes, hoists, and other load-carrying devices. [§1910.265(c)(24)(v)[b]]

[c] The ratio between the rope diameter and the drum, block, sheave, or pulley tread diameter shall be such that the rope will adjust itself to the bend without excessive wear, deformation, or injury. In no case shall the safe value of drums, blocks, sheaves, or pulleys be

Sawmills reduced when replacing such items unless compensating changes are made for rope used and for safe loading limits. [§1910.265(c)(24)(v)[c]] (vi) Drums, sheaves, and pulleys. Drums, sheaves, and pulleys shall be smooth and free from surface defects liable to injure rope. Drums, sheaves, or pulleys having eccentric bores or cracked hubs, spokes, or flanges shall be removed from service. [§1910.265(c)(24)(vi)] (vii) Connections. Connections, fittings, fastenings, and other parts used in connection with ropes and cables shall be of good quality and of proper size and strength, and shall be installed in accordance with the manufacturer's recommendations. [§1910.265(c)(24)(vii)] (viii) Socketing, splicing, and seizing. [§1910.265(c)(24)(viii)] [a] Socketing, splicing, and seizing of cables shall be performed only by qualified persons. [§1910.265(c)(24)(viii)[a]] [b] All eye splices shall be made in an approved manner and wire rope thimbles of proper size shall be fitted in the eye, except that in slings the use of thimbles shall be optional. [§1910.265(c)(24)(viii)[b]] [c] Wire rope clips attached with U-bolts shall have these bolts on the dead or short end of the rope. The U-bolt nuts shall be retightened immediately after initial load carrying use and at frequent intervals thereafter. [§1910.265(c)(24)(viii)[c]]

[d] When a wedge socket-type fastening is used, the dead or short end of the cable shall be clipped with a U-bolt or otherwise made secure against loosening. [§1910.265(c)(24)(viii)[d]]

[§1910.265(c)(24)(ix)[a]]

[b] Chain shall be normalized or annealed periodically as recommended by the manufacturer. [§1910.265(c)(24)(ix)[b]] [c] If at any time any 3-foot length of chain is found to have stretched one-third the length of a link it shall be discarded. [§1910.265(c)(24)(ix)[c]] [d] Bolts or nails shall not be placed between two links to shorten or join chains. [§1910.265(c)(24)(ix)[d]] [e] Broken chains shall not be spliced by inserting a bolt between two links with the head of the bolt and nut sustaining the load, or by passing one link through another and inserting a bolt or nail to hold it. [§1910.265(c)(24)(ix)[e]]

(x) Fiber rope. [§1910.265(c)(24)(x)] [a] Frozen fiber rope shall not be used in load carrying service. [§1910.265(c)(24)(x)[a]] [b] Fiber rope that has been subjected to acid or excessive heat shall not be used for load carrying purposes. [§1910.265(c)(24)(x)[b]]

[c] Fiber rope shall be protected from abrasion by padding where it is fastened or drawn over square corners or sharp or rough surfaces. [§1910.265(c)(24)(x)[c]] (25) [Reserved] [§1910.265(c)(25)] (26) Mechanical stackers and unstackers. [§1910.265(c)(26)] (i) [Reserved] [§1910.265(c)(26)(i)] (ii) Lumber lifting devices. Lumber lifting devices on all stackers shall be designed and arranged so as to minimize the possibility of lumber falling from such devices. [§1910.265(c)(26)(ii)]

(iii) Blocking hoisting platform. Means shall be provided to positively block the hoisting platform when employees must go beneath the stacker or unstacker hoist. [§1910.265(c)(26)(iii)]

(iv) Identifying controls. Every manually operated control switch shall be properly identified and so located as to be readily accessible to the operator. [§1910.265(c)(26)(iv)] (v) Locking main control switches. Main control switches shall be so designed that they can be locked in the open position. [§1910.265(c)(26)(v)] (vi) Guarding side openings. The hoistway side openings at the top level of the stacker and unstacker shall be protected by enclosures of standard railings. [§1910.265(c)(26)(vi)] (vii) Guarding hoistway openings. When the hoist platform or top of the load is below the working platform, the hoistway openings shall be guarded. [§1910.265(c)(26)(vii)] (viii) Guarding lower landing area. The lower landing area of stackers and unstackers shall be guarded by enclosures that prevent entrance to the area or pit below the hoist platform.

Entrances should be protected by electrically interlocked gates which, when open, will disconnect the power and set the hoist brakes. When the interlock is not installed, other positive means of protecting the entrance shall be provided. [§1910.265(c)(26)(viii)]

(ix) Inspection. Every stacker and unstacker shall be inspected at frequent intervals and all defective parts shall be immediately repaired or replaced. [§1910.265(c)(26)(ix)] (x) Cleaning pits. Safe means of entrance and exit shall be provided to permit cleaning of pits. [§1910.265(c)(26)(x)] (xi) Preventing entry to hazardous area. Where the return of trucks from unstacker to stacker is by mechanical power or gravity, adequate signs, warning devices, or barriers shall be erected to prevent entry into the hazardous area. [§1910.265(c)(26)(xi)]

(27) Lumber piling and storage. [§1910.265(c)(27)] (i) Pile foundations. In stacking units of lumber, pile foundations shall be designed and arranged to support maximum loads without sinking, sagging, or permitting the piles to topple. In unit package piles, substantial bolsters or unit separators shall be placed between each package directly over the stickers. [§1910.265(c)(27)(i)]

(ii) Stacking dissimilar unit packages. Long units of lumber shall not be stacked upon shorter packages except where a stable pile can be made with the use of package separators. [§1910.265(c)(27)(ii)]

(iii) Unstable piles. Piles of lumber which have become unstable shall be immediately made safe, or the area into which they might fall shall be fenced or barricaded and employees prohibited from entering it. [§1910.265(c)(27)(iii)] (iv) Stickers. Unit packages of lumber shall be provided with stickers as necessary to insure stability under ordinary operating conditions. [§1910.265(c)(27)(iv)] (v) Sticker alignment. Stickers shall extend the full width of the package, shall be uniformly spaced, and shall be aligned one above the other. Stickers may be lapped with a minimum overlapping of 12 inches. Stickers shall not protrude more than 2 inches beyond the sides of the package. [§1910.265(c)(27)(v)]

(vi) Pile height. The height of unit package piles shall be dependent on the dimensions of the packages and shall be such as to provide stability under normal operating conditions. Adjacent lumber piles may be tied together with separators to increase stability. [§1910.265(c)(27)(vi)] (28) Lumber loading. Loads shall be built and secured to insure stability in transit. [§1910.265(c)(28)] (29) Burners. [§1910.265(c)(29)] (i) Guying. If the burner stack is not self-supporting, it shall be guyed or otherwise supported. [§1910.265(c)(29)(i)] (ii) Runway. The conveyor runway to the burner shall be equipped with a standard handrail. If the runway crosses a roadway or thoroughfare, standard toe boards shall be provided in addition. [§1910.265(c)(29)(ii)] (30) Vehicles. [§1910.265(c)(30)] (i) Scope. Vehicles shall include all mobile equipment normally used in sawmill, planing mill, storage, shipping, and yard operations. [§1910.265(c)(30)(i)] (ii) Warning signals and spark arrestors. All vehicles shall be equipped with audible warning signals and where practicable shall have spark arrestors. [§1910.265(c)(30)(ii)] (iii) Lights. All vehicles operated in the dark or in poorly lighted areas shall be equipped with head and tail lights. [§1910.265(c)(30)(iii)]

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R Special Industries

[e] Fittings. Hooks, shackles, rings, pad eyes, and other fittings that show excessive wear or that have been bent, twisted, or otherwise damaged shall be removed from service. [§1910.265(c)(24)(viii)[e]] [f] Running lines. Running lines of hoisting equipment located within 6 feet 6 inches of the ground or working level shall be boxed off or otherwise guarded, or the operating area shall be restricted. [§1910.265(c)(24)(viii)[f]] [g] Number of wraps on drum. There shall be not less than two full wraps of hoisting cable on the drum of cranes and hoists at all times of operation. [§1910.265(c)(24)(viii)[g]] [h] Drum flanges. Drums shall have a flange at each end to prevent the cable from slipping off. [§1910.265(c)(24)(viii)[h]] [i] Sheave guards. Bottom sheaves shall be protected by close fitting guards to prevent cable from jumping the sheave. [§1910.265(c)(24)(viii)[i]] [j] Preventing abrasion. The reeving of a rope shall be so arranged as to minimize chafing or abrading while in use. [§1910.265(c)(24)(viii)[j]] (ix) Chains. [§1910.265(c)(24)(ix)] [a] Chains used in load carrying service shall be inspected before initial use and weekly thereafter.

§1910.265(c)

§1910.265

Subpart R – Special Industries (iv) Overhead guard. All vehicles operated in areas where overhead hazards exist shall be equipped with an approved overhead guard. See American National Standard Safety Code for Powered Industrial Trucks, B56.1 — 1969, which is incorporated by reference as specified in §1910.6. [§1910.265(c)(30)(iv)] (v) Platform guard. Where the operator is exposed to hazard from backing the vehicle into objects, an approved platform guard shall be provided and so arranged as to not impede exit of driver from vehicle. [§1910.265(c)(30)(v)] (vi) [Reserved] [§1910.265(c)(30)(vi)] (vii) Operation in buildings. Vehicles powered by internal combustion engines shall not operate in buildings unless the buildings are adequately ventilated. [§1910.265(c)(30)(vii)] (viii) Load limits. No vehicle shall be operated with loads exceeding its safe load capacity. [§1910.265(c)(30)(viii)] (ix) Brakes. All vehicles shall be equipped with brakes capable of holding and controlling the vehicle and capacity load upon any incline or grade over which they may be operated. [§1910.265(c)(30)(ix)]

(x) [Reserved] [§1910.265(c)(30)(x)] (xi) Carriers. [§1910.265(c)(30)(xi)] [a] Carriers shall be so designed and constructed that the operator's field of vision shall not be unnecessarily restricted. [§1910.265(c)(30)(xi)[a]] [b] Carriers shall be provided with an access ladder or equivalent. [§1910.265(c)(30)(xi)[b]] (xii) Lumber hauling trucks. [§1910.265(c)(30)(xii)] [a] On trucks where movement of load on stopping would endanger the operator, a substantial bulkhead shall be installed behind the operator's seat. This shall extend to the top of the operator's compartment. [§1910.265(c)(30)(xii)[a]]

[b] Stakes, stake pockets, racks, tighteners, and binders shall provide adequate means to secure the load against any movement during transit. [§1910.265(c)(30)(xii)[b]]

[c] Where rollers are used, at least two shall be equipped with locks which shall be locked when supporting loads during transit. [§1910.265(c)(30)(xii)[c]] (31) Traffic control and flow. [§1910.265(c)(31)] (i) Hazardous crossings. Railroad tracks and other hazardous crossings shall be plainly posted. [§1910.265(c)(31)(i)] (ii) Restricted overhead clearance. All areas of restricted side or overhead clearance shall be plainly marked. [§1910.265(c)(31)(ii)]

(iii) Pickup and unloading points. Pickup and unloading points and paths for lumber packages on conveyors and transfers and other areas where accurate spotting is required, shall be plainly marked and wheel stops provided where necessary. [§1910.265(c)(31)(iii)] (iv) Aisles, passageways, and roadways. Aisles, passageways, and roadways shall be sufficiently wide to provide safe side clearance. One-way aisles may be used for two-way traffic if suitable turnouts are provided. [§1910.265(c)(31)(iv)] (d) Log handling, sorting, and storage. [§1910.265(d)] (1) Log unloading methods, equipment, and facilities. [§1910.265(d)(1)]

(i) Unloading methods. [§1910.265(d)(1)(i)] [a] Stakes and chocks which trip shall be constructed in such manner that the tripping mechanism that releases the stake or chocks is activated at the opposite side of the load being tripped. [§1910.265(d)(1)(i)[a]] [b] Binders on logs shall not be released prior to securing with unloading lines or other unloading device. [§1910.265(d)(1)(i)[b]]

[c] Binders shall be released only from the side on which the unloader operates, except when released by remote control devices or except when person making release is protected by racks or stanchions or other equivalent means. [§1910.265(d)(1)(i)[c]] [d] Loads on which a binder is fouled by the unloading machine shall have an extra binder or metal band of equal strength placed around the load, or the load shall be otherwise secured so the fouled binder can be safely removed. [§1910.265(d)(1)(i)[d]]

(ii) Unloading equipment and facilities. [§1910.265(d)(1)(ii)] [a] Machines used for hoisting, unloading, or lowering logs shall be equipped with brakes capable of controlling or holding the maximum load in midair. [§1910.265(d)(1)(ii)[a]]

62

[b] The lifting cylinders of all hydraulically operated log handling machines shall be equipped with a positive device for preventing the uncontrolled lowering of the load or forks in case of a failure in the hydraulic system. [§1910.265(d)(1)(ii)[b]] [c] A limit switch shall be installed on powered log handling machines to prevent the lift arms from traveling too far in the event the control switch is not released in time. [§1910.265(d)(1)(ii)[c]]

[d] When forklift-type machines are used to load trailers, a means of securing the loading attachment to the fork shall be installed and used. [§1910.265(d)(1)(ii)[d]] [e] A-frames and similar log unloading devices shall have adequate height to provide safe clearance for swinging loads and to provide for adequate crotch lines and spreader bar devices. [§1910.265(d)(1)(ii)[e]] [f] Log handling machines used to stack logs or lift loads above operator's head shall be equipped with adequate overhead protection. [§1910.265(d)(1)(ii)[f]] [g] All mobile log handling machines shall be equipped with headlights and backup lights. [§1910.265(d)(1)(ii)[g]] [h] Unloading devices shall be equipped with a horn or other plainly audible signaling device. [§1910.265(d)(1)(ii)[h]] [i] Movement of unloading equipment shall be coordinated by audible or hand signals when operator's vision is impaired or operating in the vicinity of other employees. [§1910.265(d)(1)(ii)[i]]

[j] Wood pike poles shall be made of straight-grained, select material. Metal or conductive pike poles shall not be used around exposed energized electrical conductors.

Defective, blunt, or dull pike poles shall not be used. [§1910.265(d)(1)(ii)[j]]

(2) Log unloading and storage areas. [§1910.265(d)(2)] (i) General. [§1910.265(d)(2)(i)] [a] Log dumps, booms, ponds, or storage areas used at night shall be illuminated in accordance with the requirements of American National Standard A11.1-1965 (R1970) Standard Practice for Industrial Lighting, which is incorporated by reference as specified in §1910.6. [§1910.265(d)(2)(i)[a]]

[b] Log unloading areas shall be arranged and maintained to provide a safe working area. [§1910.265(d)(2)(i)[b]] [c] Where skids are used, space adequate to clear a man's body shall be maintained between the top of the skids and the ground. [§1910.265(d)(2)(i)[c]] [d] Signs prohibiting unauthorized foot or vehicle traffic in log unloading and storage areas shall be posted. [§1910.265(d)(2)(i)[d]]

(ii) Water log dumps. [§1910.265(d)(2)(ii)] [a] Ungrounded electrically powered hoists using handheld remote control in grounded locations, such as log dumps or mill log lifts, shall be actuated by circuits operating at less than 50 volts to ground. [§1910.265(d)(2)(ii)[a]]

[b] Roadbeds at log dumps shall be of sufficient width and evenness to insure safe operation of equipment. [§1910.265(d)(2)(ii)[b]]

[c] An adequate brow log or skid timbers or the equivalent shall be provided where necessary. Railroad-type dumps, when located where logs are dumped directly into water or where entire loads are lifted from vehicle, may be exempted providing such practice does not create a hazardous exposure of personnel or equipment. [§1910.265(d)(2)(ii)[c]]

[d] Unloading lines shall be arranged so that it is not necessary for the employees to attach them from the pond or dump side of the load except when entire loads are lifted from the log-transporting vehicle. [§1910.265(d)(2)(ii)[d]]

[e] Unloading lines, crotch lines, or equally effective means shall be arranged and used in a manner to minimize the possibility of any log from swinging or rolling back. [§1910.265(d)(2)(ii)[e]]

[f] When logs are unloaded with peavys or similar manual methods, means shall be provided and used that will minimize the danger from rolling or swinging logs. [§1910.265(d)(2)(ii)[f]]

[g] Guardrails, walkways, and standard handrails shall be installed [§1910.265(d)(2)(ii)[g]] [h] Approved life rings (see: 46 CFR 160.099 and 46 CFR 160.050) with line attached and maintained to retain buoyancy shall be provided. [§1910.265(d)(2)(ii)[h]]

Telecommunications (11) Safety and health meetings. The employer shall hold safety and health meetings as necessary and at least each month for each employee. Safety and health meetings may be conducted individually, in crew meetings, in larger groups, or as part of other staff meetings. [§1910.266(i)(11)] (j) Appendices. Appendices A and B of this section are mandatory.

The information contained in appendix C of this section is informational and is not intended to create any additional obligations not otherwise imposed or to detract from existing regulations. [§1910.266(j)] Note: In the Federal Register of August 9, 1995, OSHA extended the stay of the following paragraphs of §1910.266 until September 8, 1995. The remaining requirements of §1910.266, which became effective on February 9, 1995, are unaffected by the extension of the partial stay:

1. (d)(1)(v) — insofar as it requires foot protection to be chain-saw resistant. [§1910.266(j)1.]

2. (d)(1)(vii) — insofar as it required face protection. [§1910.266(j)2.]

3. (d)(2)(iii). [§1910.266(j)3.]

4. (f)(2)(iv). [§1910.266(j)4.]

5. (f)(2)(xi). [§1910.266(j)5.]

6. (f)(3)(ii). [§1910.266(j)6.]

7. (f)(3)(vii). [§1910.266(j)7.]

8. (f)(3)(viii). [§1910.266(j)8.]

9. (f)(7)(ii) — insofar as it requires parking brakes to be able to stop a moving machine. [§1910.266(j)9.]

10. (g)(1) and (g)(2) insofar as they require inspection and maintenance of employee-owned vehicles. [§1910.266(j)10.]

11. (h)(2)(vii) — insofar as it precludes backcuts at the level of the horizontal cut of the undercut when the Humboldt cutting method is used. [§1910.266(j)11.]

Appendix A to §1910.266 — First-Aid Kits (Mandatory)

Appendix B to §1910.266 — First-aid and CPR Training (Mandatory)First-aidandCPRTraining(Mandatory) The following is deemed to be the minimal acceptable first-aid and CPR training program for employees engaged in logging activities.

First-aid and CPR training shall be conducted using the conventional methods of training such as lecture, demonstration, practical exercise and examination (both written and practical). The length of training must be sufficient to assure that trainees understand the concepts of first aid and can demonstrate their ability to perform the various procedures contained in the outline below.

At a minimum, first-aid and CPR training shall consist of the following: 1. The definition of first aid.

2. Legal issues of applying first aid (Good Samaritan Laws).

3. Basic anatomy.

4. Patient assessment and first aid for the following: a. Respiratory arrest. b. Cardiac arrest. c. Hemorrhage. d. Lacerations/abrasions. e. Amputations. f. Musculoskeletal injuries. g. Shock. h. Eye injuries. i. Burns.

j. Loss of consciousness. k. Extreme temperature exposure (hypothermia/hyperthermia) l. Paralysis m. Poisoning. n. Loss of mental functioning (psychosis/hallucinations, etc.). Artificial ventilation. o. Drug overdose.

5. CPR. 6. Application of dressings and slings.

7. Treatment of strains, sprains, and fractures.

8. Immobilization of injured persons.

9. Handling and transporting injured persons.

10. Treatment of bites, stings, or contact with poisonous plants or animals.

Appendix C to §1910.266 — Comparable ISO Standards (Non-mandatory)ComparableIS OS tandards(N on-mandato ry) The following International Labor Organization (ISO) standards are comparable to the corresponding Society of Automotive Engineers (Standards that are referenced in this standard.)

Utilization of the ISO standards in lieu of the corresponding SAE standards should result in a machine that meets the OSHA standard.

SAE standard

ISO standard

SAE J1040

ISO 3471-1

Performance Criteria for Rollover Protective Structures (ROPS) for Construction, Earthmoving, Forestry and Mining Machines.

SAE J397

ISO 3164

Deflection Limiting Volume — ROPS/FOPS Laboratory Evaluation.

SAE J231

ISO 3449

Minimum Performance Criteria for Falling Object Protective Structures (FOPS).

SAE J386

ISO 6683

Operator Restraint Systems for Off-Road Work Machines.

SAE J185

ISO 2897

Access Systems for Off-Road Machines.

Subject

[59 FR 51741, Oct. 12, 1994, as amended at 60 FR 7449, Feb. 8, 1995; 60 FR 40458, Aug. 9, 1996; 60 FR 47035, Sept. 8, 1995; 61 FR 9241, 9242, Mar. 7, 1996; 69 FR 18803, Apr. 9, 2004; 71 FR 16673, Apr. 3, 2006; 79 FR 37190, July 1, 2014]

§1910.268  TelecommunicationsT elecommunications (a)  Application. [§1910.268(a)] (1)  This section sets forth safety and health standards that apply to the work conditions, practices, means, methods, operations, installations and processes performed at telecommunications centers and at telecommunications field installations, which are located outdoors or in building spaces used for such field installations. Center work includes the installation, operation, maintenance, rearrangement, and removal of communications equipment and other associated equipment in telecommunications switching centers. Field work includes the installation, operation, maintenance, rearrangement, and removal of conductors and other equipment used for signal or communication service, and of their supporting or containing structures, overhead or underground, on public or private rights of way, including buildings or other structures. [§1910.268(a)(1)] (2) These standards do not apply: [§1910.268(a)(2)] (i) To construction work, as defined in §1910.12, nor [§1910.268(a)(2)(i)]

(ii) to installations under the exclusive control of electric utilities used for the purpose of communications or metering, or for generation, control, transformation, transmission, and distribution of electric energy, which are located in buildings used exclusively by the electric utilities for such purposes, or located outdoors on property owned or leased by the electric utilities or on public highways, streets, roads, etc., or outdoors by established rights on private property. [§1910.268(a)(2)(ii)]

(3)  Operations or conditions not specifically covered by this section are subject to all the applicable standards contained in this part 1910. See §1910.5(c). Operations which involve construction work, as defined in §1910.12 are subject to all the applicable standards contained in part 1926 of this chapter. [§1910.268(a)(3)]

(b) General. [§1910.268(b)] (1) Buildings containing telecommunications centers. [§1910.268(b)(1)]

(i) Illumination. Lighting in telecommunication centers shall be provided in an adequate amount such that continuing work operations, routine observations, and the passage of employees can be carried out in a safe and healthful manner. Certain specific tasks in centers, such as splicing cable and the maintenance and repair of equipment frame lineups,

71

R Special Industries

The following list sets forth the minimally acceptable number and type of first-aid supplies for first-aid kits required under paragraph (d)(2) of the logging standard. The contents of the first-aid kit listed should be adequate for small work sites, consisting of approximately two to three employees. When larger operations or multiple operations are being conducted at the same location, additional first-aid kits should be provided at the work site or additional quantities of supplies should be included in the first-aid kits: 1. Gauze pads (at least 4 × 4 inches).

2. Two large gauze pads (at least 8 × 10 inches).

3. Box adhesive bandages (band-aids).

4. One package gauze roller bandage at least 2 inches wide.

5. Two triangular bandages.

6. Wound cleaning agent such as sealed moistened towelettes.

7. Scissors.

8. At least one blanket.

9. Tweezers.

10. Adhesive tape.

11. Latex gloves.

12. Resuscitation equipment such as resuscitation bag, airway, or pocket mask.

13. Two elastic wraps.

14. Splint.

15. Directions for requesting emergency assistance.

§1910.268(b)

§1910.268

Subpart R – Special Industries may require a higher level of illumination. In such cases, the employer shall install permanent lighting or portable supplemental lighting to attain a higher level of illumination shall be provided as needed to permit safe performance of the required task. [§1910.268(b)(1)(i)] (ii) Working surfaces. Guard rails and toe boards may be omitted on distribution frame mezzanine platforms to permit access to equipment. This exemption applies only on the side or sides of the platform facing the frames and only on those portions of the platform adjacent to equipped frames. [§1910.268(b)(1)(ii)]

(iii) Working spaces. Maintenance aisles, or wiring aisles, between equipment frame lineups are working spaces and are not an exit route for purposes of 29 CFR 1910.34. [§1910.268(b)(1)(iii)]

(iv) Special doors. When blastproof or power actuated doors are installed in specially designed hardsite security buildings and spaces, they shall be designed and installed so that they can be used as a means of egress in emergencies. [§1910.268(b)(1)(iv)] (v) Equipment, machinery and machine guarding. When power plant machinery in telecommunications centers is operated with commutators and couplings uncovered, the adjacent housing shall be clearly marked to alert personnel to the rotating machinery. [§1910.268(b)(1)(v)] (2) Battery handling. [§1910.268(b)(2)] (i) Eye protection devices which provide side as well as frontal eye protection for employees shall be provided when measuring storage battery specific gravity or handling electrolyte, and the employer shall ensure that such devices are used by the employees. The employer shall also ensure that acid resistant gloves and aprons shall be worn for protection against spattering. Facilities for quick drenching or flushing of the eyes and body shall be provided unless the storage batteries are of the enclosed type and equipped with explosion proof vents, in which case sealed water rinse or neutralizing packs may be substituted for the quick drenching or flushing facilities. Employees assigned to work with storage batteries shall be instructed in emergency procedures such as dealing with accidental acid spills. [§1910.268(b)(2)(i)]

(ii) Electrolyte (acid or base, and distilled water) for battery cells shall be mixed in a well ventilated room. Acid or base shall be poured gradually, while stirring, into the water.

Water shall never be poured into concentrated (greater than 75 percent) acid solutions. Electrolyte shall never be placed in metal containers nor stirred with metal objects. [§1910.268(b)(2)(ii)]

(iii) When taking specific gravity readings, the open end of the hydrometer shall be covered with an acid resistant material while moving it from cell to cell to avoid splashing or throwing the electrolyte. [§1910.268(b)(2)(iii)] (3) Employers must provide employees with readily accessible, adequate, and appropriate first aid supplies. A non-mandatory example of appropriate supplies is listed in Appendix A to 29 CFR 1910.151. [§1910.268(b)(3)] (4) Hazardous materials. Highway mobile vehicles and trailers stored in garages in accordance with §1910.110 may be equipped to carry more than one LP-gas container, but the total capacity of LP-gas containers per work vehicle stored in garages shall not exceed 100 pounds of LP-gas. All container valves shall be closed when not in use. [§1910.268(b)(4)] (5) Compressed gas. When using or transporting nitrogen cylinders in a horizontal position, special compartments, racks, or adequate blocking shall be provided to prevent cylinder movement. Regulators shall be removed or guarded before a cylinder is transported. [§1910.268(b)(5)] (6) Support structures. No employee, or any material or equipment, may be supported or permitted to be supported on any portion of a pole structure, platform, ladder, walkway or other elevated structure or aerial device unless the employer ensures that the support structure is first inspected by a competent person and it is determined to be adequately strong, in good working condition and properly secured in place. [§1910.268(b)(6)]

(7) Approach distances to exposed energized overhead power lines and parts. The employer shall ensure that no employee approaches or takes any conductive object closer to any electrically energized overhead power lines and parts than prescribed in Table R-2, unless: [§1910.268(b)(7)] (i) The employee is insulated or guarded from the energized parts (insulating gloves rated for the voltage involved shall be considered adequate insulation), or [§1910.268(b)(7)(i)]

72

(ii) The energized parts are insulated or guarded from the employee and any other conductive object at a different potential, or [§1910.268(b)(7)(ii)] (iii) The power conductors and equipment are deenergized and grounded. [§1910.268(b)(7)(iii)] Table R-2 — Approach Distances to Exposed Energized Overhead Power Lines and Parts Voltage range (phase to phase, RMS) 300 V and less

Approach distance (inches) ( 1)

Over 300V, not over 750V

12

Over 750V not over 2 kV

18

Over 2 kV, not over 15 kV

24

Over 15 kV, not over 37 kV

36

Over 37 kV, not over 87.5 kV

42

Over 87.5 kV, not over 121 kV

48

Over 121 kV, not over 140 kV

54

1Avoid contact.

(8) Illumination of field work. Whenever natural light is insufficient to adequately illuminate the worksite, artificial illumination shall be provided to enable the employee to perform the work safely. [§1910.268(b)(8)]

(c)  Training. Employers shall provide training in the various precautions and safe practices described in this section and shall insure that employees do not engage in the activities to which this section applies until such employees have received proper training in the various precautions and safe practices required by this section. However, where the employer can demonstrate that an employee is already trained in the precautions and safe practices required by this section prior to his employment, training need not be provided to that employee in accordance with this section.

Where training is required, it shall consist of on-the-job training or classroom-type training or a combination of both. The employer shall certify that employees have been trained by preparing a certification record which includes the identity of the person trained, the signature of the employer or the person who conducted the training, and the date the training was completed. The certification record shall be prepared at the completion of training and shall be maintained on file for the duration of the employee's employment.

The certification record shall be made available upon request to the Assistant Secretary for Occupational Safety and Health. Such training shall, where appropriate, include the following subjects: [§1910.268(c)]

(1)  Recognition and avoidance of dangers relating to encounters with harmful substances and animal, insect, or plant life; [§1910.268(c)(1)]

(2)  Procedures to be followed in emergency situations; and, [§1910.268(c)(2)]

(3)  First aid training, including instruction in artificial respiration. [§1910.268(c)(3)]

(d) Employee protection in public work areas. [§1910.268(d)] (1) Before work is begun in the vicinity of vehicular or pedestrian traffic which may endanger employees, warning signs and/or flags or other traffic control devices shall be placed conspicuously to alert and channel approaching traffic. Where further protection is needed, barriers shall be utilized. At night, warning lights shall be prominently displayed, and excavated areas shall be enclosed with protective barricades. [§1910.268(d)(1)] (2) If work exposes energized or moving parts that are normally protected, danger signs shall be displayed and barricades erected, as necessary, to warn other personnel in the area. [§1910.268(d)(2)]

(3) The employer shall insure that an employee finding any crossed or fallen wires which create or may create a hazardous situation at the work area: [§1910.268(d)(3)] (i) Remains on guard or adopts other adequate means to warn other employees of the danger and [§1910.268(d)(3)(i)] (ii) has the proper authority notified at the earliest practical moment. [§1910.268(d)(3)(ii)]

(e) Tools and personal protective equipment — Generally. Personal protective equipment, protective devices and special tools needed for the work of employees shall be provided and the employer shall ensure that they are used by employees. Before each day's use the employer shall ensure that these personal protective devices, tools, and equipment are carefully inspected by a competent person to ascertain that they are in good condition. [§1910.268(e)]

Telecommunications (f) Rubber insulating equipment. [§1910.268(f)] (1) Rubber insulating equipment designed for the voltage levels to be encountered shall be provided and the employer shall ensure that they are used by employees as required by this section. The requirements of §1910.137, Electrical Protective Equipment, shall be followed except for Table I-6. [§1910.268(f)(1)] (2) The employer is responsible for the periodic retesting of all insulating gloves, blankets, and other rubber insulating equipment. This retesting shall be electrical, visual and mechanical.

The following maximum retesting intervals shall apply: [§1910.268(f)(2)]

§1910.268(j)

(iv) Working under motor vehicles requiring hammering; [§1910.268(i)(2)(iv)]

(v) Cleaning operations using compressed air, steam, or sand blast; [§1910.268(i)(2)(v)] (vi) Acetylene welding or similar operations where sparks are thrown off; [§1910.268(i)(2)(vi)] (vii) Using powder actuated stud drivers; [§1910.268(i)(2)(vii)] (viii) Tree pruning or cutting underbrush; [§1910.268(i)(2)(viii)] (ix) Handling battery cells and solutions, such as taking battery readings with a hydrometer and thermometer; [§1910.268(i)(2)(ix)]

(x) Removing or rearranging strand or open wire; and Gloves, blankets, and other insulating equipment

Natural rubber

Synthetic rubber

New

12

18

Re-issued

9

15

[§1910.268(i)(2)(x)]

(xi) Performing lead sleeve wiping and while soldering.

Months

[§1910.268(i)(2)(xi)]

(3) Gloves and blankets shall be marked to indicate compliance with the retest schedule, and shall be marked with the date the next test is due. Gloves found to be defective in the field or by the tests set forth in paragraph (f)(2) of this section shall be destroyed by cutting them open from the finger to the gauntlet. [§1910.268(f)(3)]

[§1910.268(g)(2)(i)]

(ii) The employer shall ensure that pole climbers are inspected by a competent person for the following conditions: Fractured or cracked gaffs or leg irons, loose or dull gaffs, broken straps or buckles. If any of these conditions exist, the defect shall be corrected before the climbers are used. [§1910.268(g)(2)(ii)]

(iii) Pole climbers shall be inspected as required in this paragraph (g)(3) before each day's use and a gaff cut-out test performed at least weekly when in use. [§1910.268(g)(2)(iii)] (iv) Pole climbers may not be worn when: [§1910.268(g)(2)(iv)] [A]  Working in trees (specifically designed tree climbers shall be used for tree climbing), [§1910.268(g)(2)(iv)[A]] [B] Working on ladders, [§1910.268(g)(2)(iv)[B]] [C] Working in an aerial lift, [§1910.268(g)(2)(iv)[C]] [D] Driving a vehicle, nor [§1910.268(g)(2)(iv)[D]] [E] Walking on rocky, hard, frozen, brushy or hilly terrain. [§1910.268(g)(2)(iv)[E]]

(h)  Ladders. Ladders, step bolts, and manhole steps shall meet the applicable requirements in subpart D of this part. [§1910.268(h)] (i) Other tools and personal protective equipment. [§1910.268(i)] (1) Head protection. Head protection meeting the requirements of ANSI Z89.2-1971, "Safety Requirements for Industrial Protective Helmets for Electrical Workers, Class B” shall be provided whenever there is exposure to possible high voltage electrical contact, and the employer shall ensure that the head protection is used by employees. ANSI Z89.2-1971 is incorporated by reference as specified in §1910.6. [§1910.268(i)(1)] (2) Eye protection. Eye protection meeting the requirements of §1910.133(a)(2) thru (a)(6) shall be provided and the employer shall ensure its use by employees where foreign objects may enter the eyes due to work operations such as but not limited to: [§1910.268(i)(2)]

(i) Drilling or chipping stone, brick or masonry, breaking concrete or pavement, etc. by hand tools (sledgehammer, etc.) or power tools such as pneumatic drills or hammers; [§1910.268(i)(2)(i)]

(ii) Working on or around high speed emery or other grinding wheels unprotected by guards; [§1910.268(i)(2)(ii)] (iii) Cutting or chipping terra cotta ducts, tile, etc.; [§1910.268(i)(2)(iii)]

[§1910.268(i)(3)]

(i) The tent covers are constructed of fire resistant materials, and [§1910.268(i)(3)(i)]

(ii) Adequate ventilation is provided to maintain safe oxygen levels and avoid harmful buildup of combustion products and combustible gases. [§1910.268(i)(3)(ii)] (4) Torches. Torches may be used on aerial splicing platforms or in buckets enclosed by tents provided the tent material is constructed of fire resistant material and the torch is turned off when not in actual use. Aerial tents shall be adequately ventilated while the torch is in operation. [§1910.268(i)(4)] (5) Portable power equipment. Nominal 120V, or less, portable generators used for providing power at work locations do not require grounding if the output circuit is completely isolated from the frame of the unit. [§1910.268(i)(5)] (6) Vehicle-mounted utility generators. Vehicle-mounted utility generators used for providing nominal 240V AC or less for powering portable tools and equipment need not be grounded to earth if all of the following conditions are met: [§1910.268(i)(6)] (i) One side of the voltage source is solidly strapped to the metallic structure of the vehicle; [§1910.268(i)(6)(i)] (ii) Grounding-type outlets are used, with a "grounding” conductor between the outlet grounding terminal and the side of the voltage source that is strapped to the vehicle; [§1910.268(i)(6)(ii)]

(iii) All metallic encased tools and equipment that are powered from this system are equipped with three-wire cords and grounding-type attachment plugs, except as designated in paragraph (i)(7) of this section. [§1910.268(i)(6)(iii)] (7) Portable lights, tools, and appliances. Portable lights, tools, and appliances having noncurrent-carrying external metal housing may be used with power equipment described in paragraph (i)(5) of this section without an equipment grounding conductor.

When operated from commercial power such metal parts of these devices shall be grounded, unless these tools or appliances are protected by a system of double insulation, or its equivalent. Where such a system is employed, the equipment shall be distinctively marked to indicate double insulation. [§1910.268(i)(7)]

(8) Soldering devices. Grounding shall be omitted when using soldering irons, guns or wire-wrap tools on telecommunications circuits. [§1910.268(i)(8)] (9) Lead work. The wiping of lead joints using melted solder, gas fueled torches, soldering irons or other appropriate heating devices, and the soldering of wires or other electrical connections do not constitute the welding, cutting and brazing described in subpart Q of this part. When operated from commercial power the metal housing of electric solder pots shall be grounded. Electric solder pots may be used with the power equipment described in paragraph (i)(5) of this section without a grounding conductor. The employer shall ensure that wiping gloves or cloths and eye protection are used in lead wiping operations. A drip pan to catch hot lead drippings shall also be provided and used. [§1910.268(i)(9)] (j) Vehicle-mounted material handling devices and other mechanical equipment. [§1910.268(j)] (1) General. [§1910.268(j)(1)] (i) The employer shall ensure that visual inspections are made of the equipment by a competent person each day the equipment is to be used to ascertain that it is in good condition. [§1910.268(j)(1)(i)]

(ii) The employer shall ensure that tests shall be made at the beginning of each shift by a competent person to insure the vehicle brakes and operating systems are in proper working condition. [§1910.268(j)(1)(ii)]

73

R Special Industries

(g)  Personal climbing equipment [§1910.268(g)] (1)  General. A positioning system or a personal fall arrest system shall be provided and the employer shall ensure their use when work is performed at positions more than 4 feet (1.2 m) above the ground, on poles, and on towers, except as provided in paragraphs (n)(7) and (8) of this section. These systems shall meet the applicable requirements in subpart I of this part.

The employer shall ensure that all climbing equipment is inspected before each day's use to determine that it is in safe working condition. [§1910.268(g)(1)] (2) Pole climbers. [§1910.268(g)(2)] (i) Pole climbers may not be used if the gaffs are less than 1 1⁄4 inches in length as measured on the underside of the gaff. The gaffs of pole climbers shall be covered with safety caps when not being used for their intended use.

(3) Tent heaters. Flame-type heaters may not be used within ground tents or on platforms within aerial tents unless:

§1910.268

Subpart R – Special Industries

(2) Scrapers, loaders, dozers, graders and tractors. [§1910.268(j)(2)] (i) All rubber- tired, self-propelled scrapers, rubber-tired front end loaders, rubber-tired dozers, agricultural and industrial tractors, crawler tractors, crawler-type loaders, and motor graders, with or without attachments, that are used in telecommunications work shall have rollover protective structures that meet the requirements of subpart W of part 1926 of this Title. [§1910.268(j)(2)(i)] (ii) Eye protection shall be provided and the employer shall ensure that it is used by employees when working in areas where flying material is generated. [§1910.268(j)(2)(ii)] (3) Vehicle-mounted elevating and rotating work platforms. These devices shall not be operated with any conductive part of the equipment closer to exposed energized power lines than the clearances set forth in Table R-2 of this section. [§1910.268(j)(3)] (4) Derrick trucks and similar equipment. [§1910.268(j)(4)] (i) This equipment shall not be operated with any conductive part of the equipment closer to exposed energized power lines than the clearances set forth in Table R-2 of this section. [§1910.268(j)(4)(i)]

(ii) When derricks are used to handle poles near energized power conductors, these operations shall comply with the requirements contained in paragraphs (b)(7) and (n)(11) of this section. [§1910.268(j)(4)(ii)] (iii) Moving parts of equipment and machinery carried on or mounted on telecommunications line trucks shall be guarded. This may be done with barricades as specified in paragraph (d)(2) of this section. [§1910.268(j)(4)(iii)] (iv) Derricks and the operation of derricks shall comply with the following requirements: [§1910.268(j)(4)(iv)] [A] Manufacturer's specifications, load ratings and instructions for derrick operation shall be strictly observed. [§1910.268(j)(4)(iv)[A]]

[B] Rated load capacities and instructions related to derrick operation shall be conspicuously posted on a permanent weather-resistant plate or decal in a location on the derrick that is plainly visible to the derrick operator. [§1910.268(j)(4)(iv)[B]] [C] Prior to derrick operation the parking brake must be set and the stabilizers extended if the vehicle is so equipped. When the vehicle is situated on a grade, at least two wheels must be chocked on the downgrade side. [§1910.268(j)(4)(iv)[C]] [D] Only persons trained in the operation of the derrick shall be permitted to operate the derrick. [§1910.268(j)(4)(iv)[D]] [E] Hand signals to derrick operators shall be those prescribed by ANSI B30.6-1969, "Safety Code for Derricks”, which is incorporated by reference as specified in §1910.6. [§1910.268(j)(4)(iv)[E]] [F] The employer shall ensure that the derrick and its associated equipment are inspected by a competent person at intervals set by the manufacturer but in no case less than once per year. Records shall be maintained including the dates of inspections, and necessary repairs made, if corrective action was required. [§1910.268(j)(4)(iv)[F]]

[G] Modifications or additions to the derrick and its associated equipment that alter its capacity or affect its safe operation shall be made only with written certification from the manufacturer, or other equivalent entity, such as a nationally recognized testing laboratory, that the modification results in the equipment being safe for its intended use.

Such changes shall require the changing and posting of revised capacity and instruction decals or plates. These new ratings or limitations shall be as provided by the manufacturer or other equivalent entity. [§1910.268(j)(4)(iv)[G]] [H] Wire rope used with derricks shall be of improved plow steel or equivalent. Wire rope safety factors shall be in accordance with American National Standards Institute B30.6-1969. [§1910.268(j)(4)(iv)[H]] [I] Wire rope shall be taken out of service, or the defective portion removed, when any of the following conditions exist: [§1910.268(j)(4)(iv)[I]] [1] The rope strength has been significantly reduced due to corrosion, pitting, or excessive heat, or [§1910.268(j)(4)(iv)[I][1]]

[2] The thickness of the outer wires of the rope has been reduced to two-thirds or less of the original thickness, or [§1910.268(j)(4)(iv)[I][2]] [3] There are more than six broken wires in any one rope lay, or [§1910.268(j)(4)(iv)[I][3]] [4] There is excessive permanent distortion caused by kinking, crushing, or severe twisting of the rope. [§1910.268(j)(4)(iv)[I][4]]

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(k) Materials handling and storage. [§1910.268(k)] (1) Poles. When working with poles in piles or stacks, work shall be performed from the ends of the poles as much as possible, and precautions shall be taken for the safety of employees at the other end of the pole. During pole hauling operations, all loads shall be secured to prevent displacement. Lights, reflectors and/or flags shall be displayed on the end and sides of the load as necessary. The requirements for installation, removal, or other handling of poles in pole lines are prescribed in paragraph (n) of this section which pertains to overhead lines. In the case of hoisting machinery equipped with a positive stop loadholding device, it shall be permissible for the operator to leave his position at the controls (while a load is suspended) for the sole purpose of assisting in positioning the load prior to landing it. Prior to unloading steel, poles, crossarms, and similar material, the load shall be thoroughly examined to ascertain that the load has not shifted, that binders or stakes have not broken, and that the load is not otherwise hazardous to employees. [§1910.268(k)(1)] (2) Cable reels. Cable reels in storage shall be checked or otherwise restrained when there is a possibility that they might accidentally roll from position. [§1910.268(k)(2)] (l) Cable fault locating and testing. [§1910.268(l)] (1) Employees involved in using high voltages to locate trouble or test cables shall be instructed in the precautions necessary for their own safety and the safety of other employees. [§1910.268(l)(1)]

(2) Before the voltage is applied, cable conductors shall be isolated to the extent practicable. Employees shall be warned, by such techniques as briefing and tagging at all affected locations, to stay clear while the voltage is applied. [§1910.268(l)(2)] (m) Grounding for employee protection — pole lines. [§1910.268(m)] (1) Power conductors. Electric power conductors and equipment shall be considered as energized unless the employee can visually determine that they are bonded to one of the grounds listed in paragraph (m)(4) of this section. [§1910.268(m)(1)] (2) Nonworking open wire. Nonworking open wire communications lines shall be bonded to one of the grounds listed in paragraph (m)(4) of this section. [§1910.268(m)(2)] (3) Vertical power conduit, power ground wires and street light fixtures. [§1910.268(m)(3)]

(i) Metal power conduit on joint use poles, exposed vertical power ground wires, and street light fixtures which are below communications attachments or less than 20 inches above these attachments, shall be considered energized and shall be tested for voltage unless the employee can visually determine that they are bonded to the communications suspension strand or cable sheath. [§1910.268(m)(3)(i)] (ii) If no hazardous voltage is shown by the voltage test, a temporary bond shall be placed between such street light fixture, exposed vertical power grounding conductor, or metallic power conduit and the communications cable strand. Temporary bonds used for this purpose shall have sufficient conductivity to carry at least 500 amperes for a period of one second without fusing. [§1910.268(m)(3)(ii)] (4) Suitable protective grounding. Acceptable grounds for protective grounding are as follows: [§1910.268(m)(4)] (i) A vertical ground wire which has been tested, found safe, and is connected to a power system multigrounded neutral or the grounded neutral of a power secondary system where there are at least three services connected; [§1910.268(m)(4)(i)]

(ii) Communications cable sheath or shield and its supporting strand where the sheath or shield is: [§1910.268(m)(4)(ii)] [A] Bonded to an underground or buried cable which is connected to a central office ground, or [§1910.268(m)(4)(ii)[A]]

[B] Bonded to an underground metallic piping system, or [§1910.268(m)(4)(ii)[B]]

[C] Bonded to a power system multigrounded neutral or grounded neutral of a power secondary system which has at least three services connected; [§1910.268(m)(4)(ii)[C]]

(iii) Guys which are bonded to the grounds specified in paragraphs (m)(4)(i) and (ii) of this section and which have continuity uninterrupted by an insulator; and [§1910.268(m)(4)(iii)] (iv) If all of the preceding grounds are not available, arrays of driven ground rods where the resultant resistance to ground will be low enough to eliminate danger to personnel or permit prompt operation of protective devices. [§1910.268(m)(4)(iv)]

(5) Attaching and removing temporary bonds. When attaching grounds (bonds), the first attachment shall be made to the

Telecommunications protective ground. When removing bonds, the connection to the line or equipment shall be removed first. Insulating gloves shall be worn during these operations. [§1910.268(m)(5)] (6) Temporary grounding of suspension strand. [§1910.268(m)(6)] (i) The suspension strand shall be grounded to the existing grounds listed in paragraph (m)(4) of this section when being placed on jointly used poles or during thunderstorm activity. [§1910.268(m)(6)(i)] (ii) Where power crossings are encountered on nonjoint lines, the strand shall be bonded to an existing ground listed in paragraph (m)(4) of this section as close as possible to the crossing. This bonding is not required where crossings are made on a common crossing pole unless there is an upward change in grade at the pole. [§1910.268(m)(6)(ii)] (iii) Where roller-type bonds are used, they shall be restrained so as to avoid stressing the electrical connections. [§1910.268(m)(6)(iii)]

(iv) Bonds between the suspension strand and the existing ground shall be at least No. 6AWG copper. [§1910.268(m)(6)(iv)] (v) Temporary bonds shall be left in place until the strand has been tensioned, dead-ended, and permanently grounded. [§1910.268(m)(6)(v)]

(vi) The requirements of paragraphs (m)(6)(i) through (m)(6)(v) of this section do not apply to the installation of insulated strand. [§1910.268(m)(6)(vi)]

(7) Antenna work-radio transmitting stations 3-30 MHZ. [§1910.268(m)(7)]

(i) Prior to grounding a radio transmitting station antenna, the employer shall insure that the rigger in charge: [§1910.268(m)(7)(i)]

[A] Prepares a danger tag signed with his signature, [§1910.268(m)(7)(i)[A]]

[§1910.268(m)(7)(iii)[A]]

[B] When necessary to further reduce excessive radio frequency pickup, ground sticks or short circuits shall be placed directly on the transmission lines near the transmitter in addition to the regular grounding switches. [§1910.268(m)(7)(iii)[B]]

[C] In other cases, the antenna lines may be disconnected from ground and the transmitter to reduce pickup at the point in the field. [§1910.268(m)(7)(iii)[C]] (iv) All radio frequency line wires shall be tested for pickup with an insulated probe before they are handled either with bare hands or with metal tools. [§1910.268(m)(7)(iv)] (v) The employer shall insure that the transmitting technician warn the riggers about adjacent lines which are, or may become energized. [§1910.268(m)(7)(v)] (vi) The employer shall insure that when antenna work has been completed, the rigger in charge of the job returns to the transmitter, notifies the transmitting technician in charge that work has been completed, and personally removes the tag from the antenna ground switch. [§1910.268(m)(7)(vi)] (n) Overhead lines. [§1910.268(n)] (1) Handling suspension strand. [§1910.268(n)(1)] (i)  The employer shall insure that when handling cable suspension strand which is being installed on poles carrying exposed energized power conductors, employees shall wear insulating gloves and shall avoid body contact with the strand until after it has been tensioned, dead-ended and permanently grounded. [§1910.268(n)(1)(i)] (ii) The strand shall be restrained against upward movement during installation: [§1910.268(n)(1)(ii)] [A] On joint-use poles, where there is an upward change in grade at the pole, and [§1910.268(n)(1)(ii)[A]] [B] On non-joint-use poles, where the line croses under energized power conductors. [§1910.268(n)(1)(ii)[B]]

(2) Need for testing wood poles. Unless temporary guys or braces are attached, the following poles shall be tested in accordance with paragraph (n)(3) of this section and determined to be safe before employees are permitted to climb them: [§1910.268(n)(2)] (i) Dead-end poles, except properly braced or guyed "Y” or "T” cable junction poles, [§1910.268(n)(2)(i)] (ii) Straight line poles which are not storm guyed and where adjacent span lengths exceed 165 feet, [§1910.268(n)(2)(ii)] (iii) Poles at which there is a downward change in grade and which are not guyed or braced corner poles or cable junction poles, [§1910.268(n)(2)(iii)] (iv) Poles which support only telephone drop wire, and [§1910.268(n)(2)(iv)]

(v) Poles which carry less than ten communication line wires.

On joint use poles, one power line wire shall be considered as two communication wires for purposes of this paragraph (n)(2)(v). [§1910.268(n)(2)(v)] (3) Methods for testing wood poles. One of the following methods or an equivalent method shall be used for testing wood poles: [§1910.268(n)(3)]

(i) Rap the pole sharply with a hammer weighing about 3 pounds, starting near the ground line and continuing upwards circumferentially around the pole to a height of approximately 6 feet. The hammer will produce a clear sound and rebound sharply when striking sound wood.

Decay pockets will be indicated by a dull sound and/or a less pronounced hammer rebound. When decay pockets are indicated, the pole shall be considered unsafe. Also, prod the pole as near the ground line as possible using a pole prod or a screwdriver with a blade at least 5 inches long. If substantial decay is encountered, the pole shall be considered unsafe. [§1910.268(n)(3)(i)] (ii) Apply a horizontal force to the pole and attempt to rock it back and forth in a direction perpendicular to the line. Caution shall be exercised to avoid causing power wires to swing together. The force may be applied either by pushing with a pike pole or pulling with a rope. If the pole cracks during the test, it shall be considered unsafe. [§1910.268(n)(3)(ii)]

(4) Unsafe poles or structures. Poles or structures determined to be unsafe by test or observation may not be climbed until made safe by guying, bracing or other adequate means. Poles determined to be unsafe to climb shall, until they are made safe, be tagged in a conspicuous place to alert and warn all employees of the unsafe condition. [§1910.268(n)(4)] (5) Test requirements for cable suspension strand. [§1910.268(n)(5)] (i) Before attaching a splicing platform to a cable suspension strand, the strand shall be tested and determined to have strength sufficient to support the weight of the platform and the employee. Where the strand crosses above power wires or railroad tracks it may not be tested but shall be inspected in accordance with paragraph (n)(6) of this section. [§1910.268(n)(5)(i)]

(ii) The following method or an equivalent method shall be used for testing the strength of the strand: A rope, at least three-eighths inch in diameter, shall be thrown over the strand. On joint lines, the rope shall be passed over the strand using tree pruner handles or a wire raising tool. If two employees are present, both shall grip the double rope and slowly transfer their entire weight to the rope and attempt to raise themselves off the ground. If only one employee is present, one end of the rope which has been passed over the strand shall be tied to the bumper of the truck, or other equally secure anchorage. The employee then shall grasp the other end of the rope and attempt to raise himself off the ground. [§1910.268(n)(5)(ii)] (6) Inspection of strand. Where strand passes over electric power wires or railroad tracks, it shall be inspected from an elevated working position at each pole supporting the span in question.

The strand may not be used to support any splicing platform, scaffold or cable car, if any of the following conditions exist: [§1910.268(n)(6)]

(i) Corrosion so that no galvanizing can be detected, [§1910.268(n)(6)(i)]

(ii) One or more wires of the strand are broken, [§1910.268(n)(6)(ii)]

(iii) Worn spots, or [§1910.268(n)(6)(iii)] (iv) Burn marks such as those caused by contact with electric power wires. [§1910.268(n)(6)(iv)] (7)  Outside work platforms. Unless adequate railings are provided, safety straps and body belts shall be used while working on elevated work platforms such as aerial splicing platforms, pole platforms, ladder platforms and terminal balconies. [§1910.268(n)(7)]

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[B] Requests the transmitting technician to shutdown the transmitter and to ground the antenna with its grounding switch, [§1910.268(m)(7)(i)[B]] [C] Is notified by the transmitting technician that the transmitter has been shutdown, and [§1910.268(m)(7)(i)[C]] [D] Tags the antenna ground switch personally in the presence of the transmitting technician after the antenna has been grounded by the transmitting technician. [§1910.268(m)(7)(i)[D]] (ii) Power shall not be applied to the antenna, nor shall the grounding switch be opened under any circumstances while the tag is affixed. [§1910.268(m)(7)(ii)] (iii) [A] Where no grounding switches are provided, grounding sticks shall be used, one on each side of line, and tags shall be placed on the grounding sticks, antenna switch, or plate power switch in a conspicuous place.

§1910.268(n)

§1910.268

Subpart R – Special Industries

(8)  Other elevated locations. Safety straps and body belts shall be worn when working at elevated positions on poles, towers or similar structures, which do not have adequately guarded work areas. [§1910.268(n)(8)] (9) Installing and removing wire and cable. Before installing or removing wire or cable, the pole or structure shall be guyed, braced, or otherwise supported, as necessary, to prevent failure of the pole or structure. [§1910.268(n)(9)] (10) Avoiding contact with energized power conductors or equipment. When cranes, derricks, or other mechanized equipment are used for setting, moving, or removing poles, all necessary precautions shall be taken to avoid contact with energized power conductors or equipment. [§1910.268(n)(10)] (11) Handling poles near energized power conductors. [§1910.268(n)(11)]

(i) Joint use poles may not be set, moved, or removed where the nominal voltage of open electrical power conductors exceeds 34.5kV phase to phase (20kV to ground). [§1910.268(n)(11)(i)]

(ii) Poles that are to be placed, moved or removed during heavy rains, sleet or wet snow in joint lines carrying more than 8.7kV phase to phase voltage (5kV to ground) shall be guarded or otherwise prevented from direct contact with overhead energized power conductors. [§1910.268(n)(11)(ii)] (iii) [A] In joint lines where the power voltage is greater than 750 volts but less than 34.5kV phase to phase (20 kV to ground), wet poles being placed, moved or removed shall be insulated with either a rubber insulating blanket, a fiberglass box guide, or equivalent protective equipment. [§1910.268(n)(11)(iii)[A]] [B] In joint lines where the power voltage is greater than 8.7 kV phase to phase (5kV to ground) but less than 34.5kV phase to phase (20 kV to ground), dry poles being placed, moved, or removed shall be insulated with either a rubber insulating blanket, a fiberglass box guide, or equivalent protective equipment. [§1910.268(n)(11)(iii)[B]]

[C] Where wet or dry poles are being removed, insulation of the pole is not required if the pole is cut off 2 feet or more below the lowest power wire and also cut off near the ground line. [§1910.268(n)(11)(iii)[C]] (iv) Insulating gloves shall be worn when handling the pole with either hands or tools, when there exists a possibility that the pole may contact a power conductor. Where the voltage to ground of the power conductor exceeds 15kV to ground, Class II gloves (as defined in ANSI J6.6-1971) shall be used. For voltages not exceeding 15kV to ground, insulating gloves shall have a breakdown voltage of at least 17kV. [§1910.268(n)(11)(iv)] (v) The guard or insulating material used to protect the pole shall meet the appropriate 3 minute proof test voltage requirements contained in the ANSI J6.4-1971. [§1910.268(n)(11)(v)]

(vi) When there exists a possibility of contact between the pole or the vehicle-mounted equipment used to handle the pole, and an energized power conductor, the following precautions shall be observed: [§1910.268(n)(11)(vi)] [A] When on the vehicle which carries the derrick, avoid all contact with the ground, with persons standing on the ground, and with all grounded objects such as guys, tree limbs, or metal sign posts. To the extent feasible, remain on the vehicle as long as the possibility of contact exists. [§1910.268(n)(11)(vi)[A]] [B] When it is necessary to leave the vehicle, step onto an insulating blanket and break all contact with the vehicle before stepping off the blanket and onto the ground. As a last resort, if a blanket is not available, the employee may jump cleanly from the vehicle. [§1910.268(n)(11)(vi)[B]] [C] When it is necessary to enter the vehicle, first step onto an insulating blanket and break all contact with the ground, grounded objects and other persons before touching the truck or derrick. [§1910.268(n)(11)(vi)[C]] (12) Working position on poles. Climbing and working are prohibited above the level of the lowest electric power conducter on the pole (exclusive of vertical runs and street light wiring), except: [§1910.268(n)(12)] (i) Where communications facilities are attached above the electric power conductors, and a rigid fixed barrier is installed between the electric power facility and the communications facility, or [§1910.268(n)(12)(i)] (ii) Where the electric power conductors are cabled secondary service drops carrying less than 300 volts to ground and

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are attached 40 inches or more below the communications conductors or cables. [§1910.268(n)(12)(ii)] (13) Metal tapes and ropes. [§1910.268(n)(13)] (i) Metal measuring tapes, metal measuring ropes, or tapes containing conductive strands may not be used when working near exposed energized parts. [§1910.268(n)(13)(i)] (ii) Where it is necessary to measure clearances from energized parts, only nonconductive devices shall be used. [§1910.268(n)(13)(ii)]

(o) Underground lines. The provisions of this paragraph apply to the guarding of manholes and street openings, and to the ventilation and testing for gas in manholes and unvented vaults, where telecommunications field work is performed on or with underground lines. [§1910.268(o)] (1) Guarding manholes and street openings. [§1910.268(o)(1)] (i) When covers of manholes or vaults are removed, the opening shall be promptly guarded by a railing, temporary cover, or other suitable temporary barrier which is appropriate to prevent an accidental fall through the opening and to protect employees working in the manhole from foreign objects entering the manhole. [§1910.268(o)(1)(i)] (ii) While work is being performed in the manhole, a person with basic first aid training shall be immediately available to render assistance if there is cause for believing that a safety hazard exists, and if the requirements contained in paragraphs (d)(1) and (o)(1)(i) of this section do not adequately protect the employee(s). Examples of manhole worksite hazards which shall be considered to constitute a safety hazard include, but are not limited to: [§1910.268(o)(1)(ii)]

[A] Manhole worksites where safety hazards are created by traffic patterns that cannot be corrected by provisions of paragraph (d)(1) of this section. [§1910.268(o)(1)(ii)[A]]

[B] Manhole worksites that are subject to unusual water hazards that cannot be abated by conventional means. [§1910.268(o)(1)(ii)[B]]

[C] Manhole worksites that are occupied jointly with power utilities as described in paragraph (o)(3) of this section. [§1910.268(o)(1)(ii)[C]]

(2) Requirements prior to entering manholes and unvented vaults. [§1910.268(o)(2)]

(i) Before an employee enters a manhole, the following steps shall be taken: [§1910.268(o)(2)(i)] [A] The internal atmosphere shall be tested for combustible gas and, except when continuous forced ventilation is provided, the atmosphere shall also be tested for oxygen deficiency. [§1910.268(o)(2)(i)[A]] [B] When unsafe conditions are detected by testing or other means, the work area shall be ventilated and otherwise made safe before entry. [§1910.268(o)(2)(i)[B]] (ii) An adequate continuous supply of air shall be provided while work is performed in manholes under any of the following conditions: [§1910.268(o)(2)(ii)] [A] Where combustible or explosive gas vapors have been initially detected and subsequently reduced to a safe level by ventilation, [§1910.268(o)(2)(ii)[A]] [B] Where organic solvents are used in the work procedure, [§1910.268(o)(2)(ii)[B]]

[C] Where open flame torches are used in the work procedure, [§1910.268(o)(2)(ii)[C]]

[D] Where the manhole is located in that portion of a public right of way open to vehicular traffic and/or exposed to a seepage of gas or gases, or [§1910.268(o)(2)(ii)[D]] [E] Where a toxic gas or oxygen deficiency is found. [§1910.268(o)(2)(ii)[E]]

(iii) [A] The requirements of paragraphs (o)(2) (i) and (ii) of this section do not apply to work in central office cable vaults that are adequately ventilated. [§1910.268(o)(2)(iii)[A]] [B] The requirements of paragraphs (o)(2) (i) and (ii) of this section apply to work in unvented vaults. [§1910.268(o)(2)(iii)[B]]

(3) Joint power and telecommunication manholes. While work is being performed in a manhole occupied jointly by an electric utility and a telecommunication utility, an employee with basic first aid training shall be available in the immediate vicinity to render emergency assistance as may be required. The employee whose presence is required in the immediate vicinity for the purposes of rendering emergency assistance is not to be precluded from occasionally entering a manhole to provide assistance other than in an emergency. The requirement of this paragraph (o)(3) does not preclude a qualified employee,

Electric power generation, transmission, and distribution (ii)  No later than April 1, 2015, for voltages over 72.5 kilovolts, the employer shall determine the maximum anticipated per-unit transient overvoltage, phase-to-ground, through an engineering analysis or assume a maximum anticipated per-unit transient overvoltage, phase-to-ground, in accordance with Table R-9. When the employer uses portable protective gaps to control the maximum transient overvoltage, the value of the maximum anticipated per-unit transient overvoltage, phase-to-ground, must provide for five standard deviations between the statistical sparkover voltage of the gap and the statistical withstand voltage corresponding to the electrical component of the minimum approach distance. The employer shall make any engineering analysis conducted to determine maximum anticipated per-unit transient overvoltage available upon request to employees and to the Assistant Secretary or designee for examination and copying. [§1910.269(l)(3)(ii)] Note to paragraph (l)(3)(ii): See Appendix B to this section for information on how to calculate the maximum anticipated per-unit transient overvoltage, phaseto-ground, when the employer uses portable protective gaps to reduce maximum transient overvoltages.

[§1910.269(l)(4)(i)[A]]

[B] When installing insulation for purposes of paragraph (l)(4)(i)(A) of this section, the employee installs the insulation from a position that does not expose his or her upper arm to contact with other energized parts. [§1910.269(l)(4)(i)[B]]

(ii) When an employee uses rubber insulating gloves or rubber insulating gloves and sleeves as insulation from energized parts (under paragraph (l)(3)(iii)(A) of this section), the employer shall ensure that the employee: [§1910.269(l)(4)(ii)] [A] Puts on the rubber insulating gloves and sleeves in a position where he or she cannot reach into the minimum approach distance, established by the employer under paragraph (l)(3)(i) of this section; and [§1910.269(l)(4)(ii)[A]] [B] Does not remove the rubber insulating gloves and sleeves until he or she is in a position where he or she cannot reach into the minimum approach distance, established by the employer under paragraph (l)(3)(i) of this section. [§1910.269(l)(4)(ii)[B]]

(5) Working position. [§1910.269(l)(5)] (i) The employer shall ensure that each employee, to the extent that other safety-related conditions at the worksite permit, works in a position from which a slip or shock will not bring the employee's body into contact with exposed, uninsulated parts energized at a potential different from the employee's. [§1910.269(l)(5)(i)]

(ii) When an employee performs work near exposed parts energized at more than 600 volts, but not more than 72.5 kilovolts, and is not wearing rubber insulating gloves, being protected by insulating equipment covering the energized parts, performing work using live-line tools, or performing live-line barehand work under paragraph (q)(3) of this section, the employee shall work from a position where he or she cannot reach into the minimum approach distance, established by the employer under paragraph (l)(3)(i) of this section. [§1910.269(l)(5)(ii)]

(6) Making connections. The employer shall ensure that employees make connections as follows: [§1910.269(l)(6)] (i) In connecting deenergized equipment or lines to an energized circuit by means of a conducting wire or device, an employee shall first attach the wire to the deenergized part; [§1910.269(l)(6)(i)]

(ii) When disconnecting equipment or lines from an energized circuit by means of a conducting wire or device, an employee shall remove the source end first; and [§1910.269(l)(6)(ii)]

(iii)  When lines or equipment are connected to or disconnected from energized circuits, an employee shall keep loose conductors away from exposed energized parts. [§1910.269(l)(6)(iii)]

(7) Conductive articles. When an employee performs work within reaching distance of exposed energized parts of equipment, the employer shall ensure that the employee removes or renders nonconductive all exposed conductive articles, such as keychains or watch chains, rings, or wrist watches or bands, unless such articles do not increase the hazards associated with contact with the energized parts. [§1910.269(l)(7)] (8)  Protection from flames and electric arcs. [§1910.269(l)(8)] (i) The employer shall assess the workplace to identify employees exposed to hazards from flames or from electric arcs. [§1910.269(l)(8)(i)]

(ii)  For each employee exposed to hazards from electric arcs, the employer shall make a reasonable estimate of the incident heat energy to which the employee would be exposed. [§1910.269(l)(8)(ii)] Note 1 to paragraph (l)(8)(ii): Appendix E to this section provides guidance on estimating available heat energy. The Occupational Safety and Health Administration will deem employers following the guidance in Appendix E to this section to be in compliance with paragraph (l)(8)(ii) of this section. An employer may choose a method of calculating incident heat energy not included in Appendix E to this section if the chosen method reasonably predicts the incident energy to which the employee would be exposed.

Note 2 to paragraph (l)(8)(ii): This paragraph does not require the employer to estimate the incident heat energy exposure for every job task performed by each employee. The employer may make broad estimates that cover multiple system areas provided the employer uses reasonable assumptions about the energy-exposure distribution throughout the system and provided the estimates represent the maximum employee exposure for those areas. For example, the employer could estimate the heat energy just outside a substation feeding a radial distribution system and use that estimate for all jobs performed on that radial system.

(iii) The employer shall ensure that each employee who is exposed to hazards from flames or electric arcs does not wear clothing that could melt onto his or her skin or that could ignite and continue to burn when exposed to flames or the heat energy estimated under paragraph (l)(8)(ii) of this section. [§1910.269(l)(8)(iii)] Note to paragraph (l)(8)(iii) of this section: This paragraph prohibits clothing made from acetate, nylon, polyester, rayon and polypropylene, either alone or in blends, unless the employer demonstrates that the fabric has been treated to withstand the conditions that may be encountered by the employee or that the employee wears the clothing in such a manner as to eliminate the hazard involved.

(iv) The employer shall ensure that the outer layer of clothing worn by an employee, except for clothing not required to be arc rated under paragraphs (l)(8)(v)(A) through (l)(8)(v)(E) of this section, is flame resistant under any of the following conditions: [§1910.269(l)(8)(iv)] [A] The employee is exposed to contact with energized circuit parts operating at more than 600 volts, [§1910.269(l)(8)(iv)[A]]

[B] An electric arc could ignite flammable material in the work area that, in turn, could ignite the employee's clothing, [§1910.269(l)(8)(iv)[B]] [C] Molten metal or electric arcs from faulted conductors in the work area could ignite the employee's clothing, or [§1910.269(l)(8)(iv)[C]] Note to paragraph (l)(8)(iv)(C): This paragraph does not apply to conductors that are capable of carrying, without failure, the maximum available fault current for the time the circuit protective devices take to interrupt the fault.

[D] The incident heat energy estimated under paragraph (l)(8)(ii) of this section exceeds 2.0 cal/cm2. [§1910.269(l)(8)(iv)[D]] (v)  The employer shall ensure that each employee exposed to hazards from electric arcs wears protective clothing and other protective equipment with an arc rating greater than or equal to the heat energy estimated under paragraph (l)(8)(ii) of this section whenever that estimate exceeds 2.0 cal/cm2.

This protective equipment shall cover the employee's entire body, except as follows: [§1910.269(l)(8)(v)] [A] Arc-rated protection is not necessary for the employee's hands when the employee is wearing rubber insulating gloves with protectors or, if the estimated incident energy is no more than 14 cal/cm2, heavy-duty leather work gloves with a weight of at least 407 gm/m2 (12 oz/yd2), [§1910.269(l)(8)(v)[A]]

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(iii) The employer shall ensure that no employee approaches or takes any conductive object closer to exposed energized parts than the employer's established minimum approach distance, unless: [§1910.269(l)(3)(iii)] [A] The employee is insulated from the energized part (rubber insulating gloves or rubber insulating gloves and sleeves worn in accordance with paragraph (l)(4) of this section constitutes insulation of the employee from the energized part upon which the employee is working provided that the employee has control of the part in a manner sufficient to prevent exposure to uninsulated portions of the employee's body), or [§1910.269(l)(3)(iii)[A]] [B] The energized part is insulated from the employee and from any other conductive object at a different potential, or [§1910.269(l)(3)(iii)[B]] [C] The employee is insulated from any other exposed conductive object in accordance with the requirements for live-line barehand work in paragraph (q)(3) of this section. [§1910.269(l)(3)(iii)[C]] (4)  Type of insulation. [§1910.269(l)(4)] (i) When an employee uses rubber insulating gloves as insulation from energized parts (under paragraph (l)(3)(iii)(A) of this section), the employer shall ensure that the employee also uses rubber insulating sleeves. However, an employee need not use rubber insulating sleeves if: [§1910.269(l)(4)(i)] [A] Exposed energized parts on which the employee is not working are insulated from the employee; and

§1910.269(l)

§1910.269

Subpart R – Special Industries [B] Arc-rated protection is not necessary for the employee's feet when the employee is wearing heavy-duty work shoes or boots, [§1910.269(l)(8)(v)[B]] [C] Arc-rated protection is not necessary for the employee's head when the employee is wearing head protection meeting §1910.135 if the estimated incident energy is less than 9 cal/cm2 for exposures involving single-phase arcs in open air or 5 cal/cm2 for other exposures, [§1910.269(l)(8)(v)[C]]

[D] The protection for the employee's head may consist of head protection meeting §1910.135 and a faceshield with a minimum arc rating of 8 cal/cm2 if the estimated incident-energy exposure is less than 13 cal/cm2 for exposures involving single-phase arcs in open air or 9 cal/cm2 for other exposures, and [§1910.269(l)(8)(v)[D]] [E] For exposures involving single-phase arcs in open air, the arc rating for the employee's head and face protection may be 4 cal/cm2 less than the estimated incident energy. [§1910.269(l)(8)(v)[E]]

Table R-3 — AC Live-Line Work Minimum Approach Distance [The minimum (continued)

approach distance (MAD; in meters) shall conform to the following equations.]

[§1910.269(l)(8)(vi)[C]]

(9) Fuse handling. When an employee must install or remove fuses with one or both terminals energized at more than 300 volts, or with exposed parts energized at more than 50 volts, the employer shall ensure that the employee uses tools or gloves rated for the voltage. When an employee installs or removes expulsion-type fuses with one or both terminals energized at more than 300 volts, the employer shall ensure that the employee wears eye protection meeting the requirements of Subpart I of this part, uses a tool rated for the voltage, and is clear of the exhaust path of the fuse barrel. [§1910.269(l)(9)] (10) Covered (noninsulated) conductors. The requirements of this section that pertain to the hazards of exposed live parts also apply when an employee performs work in proximity to covered (noninsulated) wires. [§1910.269(l)(10)] (11) Non-current-carrying metal parts. Non-current-carrying metal parts of equipment or devices, such as transformer cases and circuit-breaker housings, shall be treated as energized at the highest voltage to which these parts are exposed, unless the employer inspects the installation and determines that these parts are grounded before employees begin performing the work. [§1910.269(l)(11)] (12) Opening and closing circuits under load. [§1910.269(l)(12)] (i) The employer shall ensure that devices used by employees to open circuits under load conditions are designed to interrupt the current involved. [§1910.269(l)(12)(i)] (ii) The employer shall ensure that devices used by employees to close circuits under load conditions are designed to safely carry the current involved. [§1910.269(l)(12)(ii)] Table R-3 — AC Live-Line Work Minimum Approach Distance [The minimum approach distance (MAD; in meters) shall conform to the following equations.]

D = the value from Table R-4 corresponding to the voltage and exposure or the value of the electrical component of the minimum approach distance calculated using the method provided in Appendix B to this section

the electrical component of the minimum approach distance.

MAD = 0.3048(C + a)VL-GTA + M C = 0.01 for phase-to-ground exposures that the employer can demonstrate consist only of air across the approach distance (gap), 0.01 for phase-to-phase exposures if the employer can demonstrate that no insulated tool spans the gap and that no large conductive object is in the gap, or 0.011 otherwise VL-G = phase-to-ground rms voltage, in kV T = maximum anticipated per-unit transient overvoltage; for phase-to-ground exposures, T equals TL-G, the maximum per-unit transient overvoltage, phase-toground, determined by the employer under paragraph (l)(3)(ii) of this section; for phase-to-phase exposures, T equals 1.35TL-G + 0.45 A = altitude correction factor from Table R-5 M = 0.31 m, the inadvertent movement factor a = saturation factor, as follows: Phase-to-Ground Exposures VPeak = TL-GVL-G2

635 kV or less

635.1 to 915 kV

915.1 to 1,050 kV

More than 1,050 kV

a

0

(VPeak635)/ 140,000

(VPeak645)/ 135,000

(VPeak-675)/125,000

Phase-to-Phase Exposures3 VPeak = (1.35TL-G + 0.45)VL-G2

630 kV or less

630.1 to 848 kV

848.1 to 1,131 kV

1,131.1 to 1,485 kV

More than 1,485 kV

a

0

(VPeak630)/ 155,000

(VPeak633.6)/ 152,207

(VPeak628)/ 153,846

(VPeak350.5)/ 203,666

1Employers may use the minimum approach distances in Table R-6. If the worksite is at an

elevation of more than 900 meters (3,000 feet), see footnote 1 to Table R-6.

2Employers may use the minimum approach distances in Table R-7, except that the employer

may not use the minimum approach distances in Table R-7 for phase-to-phase exposures if an insulated tool spans the gap or if any large conductive object is in the gap. If the worksite is at an elevation of more than 900 meters (3,000 feet), see footnote 1 to Table R-7. Employers may use the minimum approach distances in Table 14 through Table 21 in Appendix B to this section, which calculated MAD for various values of T, provided the employer follows the notes to those tables.

3 Use the equations for phase-to-ground exposures (with VPeak for phase-to-phase exposures) unless the employer can demonstrate that no insulated tool spans the gap and that no large conductive object is in the gap.

4

Until March 31, 2015, employers may use the minimum approach distances in Table 6 through Table 13 in Appendix B to this section.

Table R-4 — Electrical Component of the Minimum Approach Distance at 5.1 to 72.5 kV [D; In meters] Nominal voltage (kV) phase-to-phase

Phase-to-ground exposure

Phase-to-phase exposure

D (m)

D (m)

5.1 to 15.0

0.04

0.07

15.1 to 36.0

0.16

0.28

36.1 to 46.0

0.23

0.37

46.1 to 72.5

0.39

0.59

Table R-5 — Altitude Correction Factor

For phase-to-phase system voltages of 50 V to 300 V:1 MAD = avoid contact For phase-to-phase system voltages of 301 V to 5 kV:1 MAD = M + D, where D = 0.02 m

the altitude correction factor.

For phase-to-phase system voltages of more than 72.5 kV, nominal:2 4

Note to paragraph (l)(8): See Appendix E to this section for further information on the selection of appropriate protection. (vi) Dates. [§1910.269(l)(8)(vi)]

[A] The obligation in paragraph (l)(8)(ii) of this section for the employer to make reasonable estimates of incident energy commences January 1, 2015. [§1910.269(l)(8)(vi)[A]] [B] The obligation in paragraph (l)(8)(iv)(D) of this section for the employer to ensure that the outer layer of clothing worn by an employee is flame-resistant when the estimated incident heat energy exceeds 2.0 cal/cm2 commences April 1, 2015. [§1910.269(l)(8)(vi)[B]] [C] The obligation in paragraph (l)(8)(v) of this section for the employer to ensure that each employee exposed to hazards from electric arcs wears the required arc-rated protective equipment commences April 1, 2015.

A = the applicable value from Table R-5

the electrical component of the minimum approach distance.

Altitude above sea level (m)

A

0 to 900

1.00

901 to 1,200

1.02

1,201 to 1,500

1.05

1,501 to 1,800

1.08

1,801 to 2,100

1.11

2,101 to 2,400

1.14

For phase-to-phase system voltages of 5.1 kV to 72.5 kV:1 4

2,401 to 2,700

1.17

MAD = M + AD, where

2,701 to 3,000

1.20

3,001 to 3,600

1.25

3,601 to 4,200

1.30

M = 0.31 m for voltages up to 750 V and 0.61 m otherwise

M = 0.61 m

88

the inadvertent movement factor.

the inadvertent movement factor.

Electric power generation, transmission, and distribution Table R-5 — Altitude Correction Factor

(continued)

Altitude above sea level (m)

A

4,201 to 4,800

1.35

4,801 to 5,400

1.39

5,401 to 6,000

1.44

Distance Phase-to-ground exposure

Phase-to-phase exposure

m

m

2

ft

Avoid Contact

0.050 to 0.300

ft

Avoid Contact

0.301 to 0.7502

0.33

1.09

0.33

1.09

0.751 to 5.0

0.63

2.07

0.63

2.07

5.1 to 15.0

0.65

2.14

0.68

2.24

15.1 to 36.0

0.77

2.53

0.89

2.92

36.1 to 46.0

0.84

2.76

0.98

3.22

46.1 to 72.5

1.00

3.29

1.20

3.94

at an elevation of 900 meters (3,000 feet) or less. If employees will be working at elevations greater than 900 meters (3,000 feet) above mean sea level, the employer shall determine minimum approach distances by multiplying the distances in this table by the correction factor in Table R-5 corresponding to the altitude of the work.

For single-phase systems, use voltage-to-ground.

Table R-7 — Alternative Minimum Approach Distances for Voltages of More Than 72.5 kV1 2 3

72.6 to 121.0

Phase-to-ground exposure m

ft

m

ft

1.13

3.71

1.42

4.66

121.1 to 145.0

1.30

4.27

1.64

5.38

145.1 to 169.0

1.46

4.79

1.94

6.36 10.10

169.1 to 242.0

2.01

6.59

3.08

242.1 to 362.0

3.41

11.19

5.52

18.11

362.1 to 420.0

4.25

13.94

6.81

22.34

420.1 to 550.0

5.07

16.63

8.24

27.03

550.1 to 800.0

6.88

22.57

11.38

37.34

3The clear live-line tool distance shall equal or exceed the values for the indicated voltage

ranges.

Table R-8 — DC Live-Line Minimum Approach Distance with Overvoltage Factor1 [In meters] Distance (m) maximum line-to-ground voltage (kV)

Maximum anticipated per-unit transient overvoltage

250

400

500

600

750

1.5 or less

1.12

1.60

2.06

2.62

3.61

1.6

1.17

1.69

2.24

2.86

3.98

1.7

1.23

1.82

2.42

3.12

4.37

1.8

1.28

1.95

2.62

3.39

4.79

employees will be working at elevations greater than 900 meters (3,000 feet) above mean sea level, the employer shall determine minimum approach distances by multiplying the distances in this table by the correction factor in Table R-5 corresponding to the altitude of the work.

x

Voltage range (kV)

Type of current (ac or dc)

Assumed maximum per-unit transient overvoltage 3.5 3.0

ac

2.5

(1)  Application. Paragraph (m) of this section applies to the deenergizing of transmission and distribution lines and equipment for the purpose of protecting employees. See paragraph (d) of this section for requirements on the control of hazardous energy sources used in the generation of electric energy. Conductors and parts of electric equipment that have been deenergized under procedures other than those required by paragraph (d) or (m) of this section, as applicable, shall be treated as energized. [§1910.269(m)(1)] (2) General. [§1910.269(m)(2)] (i) If a system operator is in charge of the lines or equipment and their means of disconnection, the employer shall designate one employee in the crew to be in charge of the clearance and shall comply with all of the requirements of paragraph (m)(3) of this section in the order specified. (ii) If no system operator is in charge of the lines or equipment and their means of disconnection, the employer shall designate one employee in the crew to be in charge of the clearance and to perform the functions that the system operator would otherwise perform under paragraph (m) of this section. All of the requirements of paragraph (m)(3) of this section apply, in the order specified, except as provided in paragraph (m)(2)(iii) of this section.

[B] Each crew shall independently comply with paragraph (m) of this section and, if there is no system operator in charge of the lines or equipment, shall have separate tags and coordinate deenergizing and reenergizing the lines and equipment with the other crews. [§1910.269(m)(2)(iv)[B]]

(v) The employer shall render any disconnecting means that are accessible to individuals outside the employer's control (for example, the general public) inoperable while the disconnecting means are open for the purpose of protecting employees. [§1910.269(m)(2)(v)] (3) Deenergizing lines and equipment. [§1910.269(m)(3)] (i) The employee that the employer designates pursuant to paragraph (m)(2) of this section as being in charge of the clearance shall make a request of the system operator to deenergize the particular section of line or equipment.

The designated employee becomes the employee in charge (as this term is used in paragraph (m)(3) of this section) and is responsible for the clearance. [§1910.269(m)(3)(i)]

1The distances specified in this table are for air, bare-hand, and live-line tool conditions. If

550.1 to 800.0

[§1910.269(m)]

[§1910.269(m)(2)(iv)[A]]

Employers may use the phase-to-phase minimum approach distances in this table provided that no insulated tool spans the gap and no large conductive object is in the gap.

ac

1.8

[§1910.269(m)(2)(iii)]

2

ac

dc

(iv) If two or more crews will be working on the same lines or equipment, then: [§1910.269(m)(2)(iv)] [A] The crews shall coordinate their activities under paragraph (m) of this section with a single employee in charge of the clearance for all of the crews and follow the requirements of paragraph (m) of this section as if all of the employees formed a single crew, or

at an elevation of 900 meters (3,000 feet) or less. If employees will be working at elevations greater than 900 meters (3,000 feet) above mean sea level, the employer shall determine minimum approach distances by multiplying the distances in this table by the correction factor in Table R-5 corresponding to the altitude of the work.

72.6 to 420.0

250 to 750

[§1910.269(m)(2)(ii)]

1Employers may use the minimum approach distances in this table provided the worksite is

420.1 to 550.0

Assumed maximum per-unit transient overvoltage

(iii) If only one crew will be working on the lines or equipment and if the means of disconnection is accessible and visible to, and under the sole control of, the employee in charge of the clearance, paragraphs (m)(3)(i), (m)(3)(iii), and (m)(3)(v) of this section do not apply. Additionally, the employer does not need to use the tags required by the remaining provisions of paragraph (m)(3) of this section.

Phase-to-phase exposure

Table R-9 — Assumed Maximum Per-Unit Transient Overvoltage x

Type of current (ac or dc)

(ii)  The employer shall ensure that all switches, disconnectors, jumpers, taps, and other means through which known sources of electric energy may be supplied to the particular lines and equipment to be deenergized are open. The employer shall render such means inoperable, unless its design does not so permit, and then ensure that such means are tagged to indicate that employees are at work. [§1910.269(m)(3)(ii)]

(iii) The employer shall ensure that automatically and remotely controlled switches that could cause the opened disconnecting means to close are also tagged at the points of control. The employer shall render the automatic or remote control feature inoperable, unless its design does not so permit. [§1910.269(m)(3)(iii)]

89

R Special Industries

Voltage range phase to phase (kV)

Voltage range (kV)

[§1910.269(m)(2)(i)]

1Employers may use the minimum approach distances in this table provided the worksite is

2

Table R-9 — Assumed Maximum Per-Unit Transient Overvoltage x x (continued)

(m)  Deenergizing lines and equipment for employee protection.

Table R-6 — Alternative Minimum Approach Distances for Voltages of 72.5 kV and Less1 Nominal voltage (kV) phase-to-phase

§1910.269(m)

§1910.269

Subpart R – Special Industries (iv) The employer need not use the tags mentioned in paragraphs (m)(3)(ii) and (m)(3)(iii) of this section on a network protector for work on the primary feeder for the network protector's associated network transformer when the employer can demonstrate all of the following conditions: [§1910.269(m)(3)(iv)]

[A] Every network protector is maintained so that it will immediately trip open if closed when a primary conductor is deenergized; [§1910.269(m)(3)(iv)[A]] [B] Employees cannot manually place any network protector in a closed position without the use of tools, and any manual override position is blocked, locked, or otherwise disabled; and [§1910.269(m)(3)(iv)[B]] [C] The employer has procedures for manually overriding any network protector that incorporate provisions for determining, before anyone places a network protector in a closed position, that: The line connected to the network protector is not deenergized for the protection of any employee working on the line; and (if the line connected to the network protector is not deenergized for the protection of any employee working on the line) the primary conductors for the network protector are energized. [§1910.269(m)(3)(iv)[C]]

(v) Tags shall prohibit operation of the disconnecting means and shall indicate that employees are at work. [§1910.269(m)(3)(v)]

(vi) After the applicable requirements in paragraphs (m)(3)(i) through (m)(3)(v) of this section have been followed and the system operator gives a clearance to the employee in charge, the employer shall ensure that the lines and equipment are deenergized by testing the lines and equipment to be worked with a device designed to detect voltage. [§1910.269(m)(3)(vi)] (vii) The employer shall ensure the installation of protective grounds as required by paragraph (n) of this section. [§1910.269(m)(3)(vii)]

(viii)  After the applicable requirements of paragraphs (m)(3)(i) through (m)(3)(vii) of this section have been followed, the lines and equipment involved may be considered deenergized. [§1910.269(m)(3)(viii)]

(ix)  To transfer the clearance, the employee in charge (or the employee's supervisor if the employee in charge must leave the worksite due to illness or other emergency) shall inform the system operator and employees in the crew; and the new employee in charge shall be responsible for the clearance. [§1910.269(m)(3)(ix)] (x) To release a clearance, the employee in charge shall: [§1910.269(m)(3)(x)]

[A] Notify each employee under that clearance of the pending release of the clearance; [§1910.269(m)(3)(x)[A]] [B] Ensure that all employees under that clearance are clear of the lines and equipment; [§1910.269(m)(3)(x)[B]] [C] Ensure that all protective grounds protecting employees under that clearance have been removed; and [§1910.269(m)(3)(x)[C]]

[D] Report this information to the system operator and then release the clearance. [§1910.269(m)(3)(x)[D]] (xi) Only the employee in charge who requested the clearance may release the clearance, unless the employer transfers responsibility under paragraph (m)(3)(ix) of this section. [§1910.269(m)(3)(xi)]

(xii) No one may remove tags without the release of the associated clearance as specified under paragraphs (m)(3)(x) and (m)(3)(xi) of this section. [§1910.269(m)(3)(xii)] (xiii) The employer shall ensure that no one initiates action to reenergize the lines or equipment at a point of disconnection until all protective grounds have been removed, all crews working on the lines or equipment release their clearances, all employees are clear of the lines and equipment, and all protective tags are removed from that point of disconnection. [§1910.269(m)(3)(xiii)] (n)  Grounding for the protection of employees. [§1910.269(n)] (1) Application. Paragraph (n) of this section applies to grounding of generation, transmission, and distribution lines and equipment for the purpose of protecting employees. Paragraph (n)(4) of this section also applies to protective grounding of other equipment as required elsewhere in this section. [§1910.269(n)(1)] Note to paragraph (n)(1): This paragraph covers grounding of generation, transmission, and distribution lines and equipment when this section requires protective grounding and whenever the employer chooses to ground such lines and equipment for the protection of employees.

(2)  General. For any employee to work transmission and distribution lines or equipment as deenergized, the employer shall

90

ensure that the lines or equipment are deenergized under the provisions of paragraph (m) of this section and shall ensure proper grounding of the lines or equipment as specified in paragraphs (n)(3) through (n)(8) of this section. However, if the employer can demonstrate that installation of a ground is impracticable or that the conditions resulting from the installation of a ground would present greater hazards to employees than working without grounds, the lines and equipment may be treated as deenergized provided that the employer establishes that all of the following conditions apply: [§1910.269(n)(2)] (i) The employer ensures that the lines and equipment are deenergized under the provisions of paragraph (m) of this section. [§1910.269(n)(2)(i)] (ii) There is no possibility of contact with another energized source. [§1910.269(n)(2)(ii)]

(iii) The hazard of induced voltage is not present. [§1910.269(n)(2)(iii)]

(3) Equipotential zone. Temporary protective grounds shall be placed at such locations and arranged in such a manner that the employer can demonstrate will prevent each employee from being exposed to hazardous differences in electric potential. [§1910.269(n)(3)] Note to paragraph (n)(3): Appendix C to this section contains guidelines for establishing the equipotential zone required by this paragraph. The Occupational Safety and Health Administration will deem grounding practices meeting these guidelines as complying with paragraph (n)(3) of this section.

(4) Protective grounding equipment. [§1910.269(n)(4)]

(i) Protective grounding equipment shall be capable of conducting the maximum fault current that could flow at the point of grounding for the time necessary to clear the fault. [§1910.269(n)(4)(i)]

(ii) Protective grounding equipment shall have an ampacity greater than or equal to that of No. 2 AWG copper. [§1910.269(n)(4)(ii)]

(iii) Protective grounds shall have an impedance low enough so that they do not delay the operation of protective devices in case of accidental energizing of the lines or equipment. [§1910.269(n)(4)(iii)] Note to paragraph (n)(4): American Society for Testing and Materials Standard Specifications for Temporary Protective Grounds to Be Used on De-Energized Electric Power Lines and Equipment, ASTM F855-09, contains guidelines for protective grounding equipment. The Institute of Electrical Engineers Guide for Protective Grounding of Power Lines, IEEE Std 1048-2003, contains guidelines for selecting and installing protective grounding equipment.

(5) Testing. The employer shall ensure that, unless a previously installed ground is present, employees test lines and equipment and verify the absence of nominal voltage before employees install any ground on those lines or that equipment. [§1910.269(n)(5)]

(6)  Connecting and removing grounds. [§1910.269(n)(6)] (i) The employer shall ensure that, when an employee attaches a ground to a line or to equipment, the employee attaches the ground-end connection first and then attaches the other end by means of a live-line tool. For lines or equipment operating at 600 volts or less, the employer may permit the employee to use insulating equipment other than a live-line tool if the employer ensures that the line or equipment is not energized at the time the ground is connected or if the employer can demonstrate that each employee is protected from hazards that may develop if the line or equipment is energized. [§1910.269(n)(6)(i)]

(ii) The employer shall ensure that, when an employee removes a ground, the employee removes the grounding device from the line or equipment using a live-line tool before he or she removes the ground-end connection. For lines or equipment operating at 600 volts or less, the employer may permit the employee to use insulating equipment other than a live-line tool if the employer ensures that the line or equipment is not energized at the time the ground is disconnected or if the employer can demonstrate that each employee is protected from hazards that may develop if the line or equipment is energized. [§1910.269(n)(6)(ii)]

(7)  Additional precautions. The employer shall ensure that, when an employee performs work on a cable at a location remote from the cable terminal, the cable is not grounded at the cable terminal if there is a possibility of hazardous transfer of potential should a fault occur. [§1910.269(n)(7)] (8) Removal of grounds for test. The employer may permit employees to remove grounds temporarily during tests. During the test procedure, the employer shall ensure that each employee uses insulating equipment, shall isolate each employee from any hazards involved, and shall implement any additional measures necessary to protect each exposed employee in case the previously grounded lines and equipment become energized. [§1910.269(n)(8)]

Electric power generation, transmission, and distribution or a combination of conductors insulated from one another (multiple-conductor cable).

Cable sheath. A conductive protective covering applied to cables.

Note to the definition of "cable sheath”: A cable sheath may consist of multiple layers one or more of which is conductive.

Circuit. A conductor or system of conductors through which an electric current is intended to flow.

Clearance (between objects). The clear distance between two objects measured surface to surface.

Clearance (for work). Authorization to perform specified work or permission to enter a restricted area.

Communication lines. (See Lines; (1) Communication lines.)

Conductor. A material, usually in the form of a wire, cable, or bus bar, used for carrying an electric current.

Contract employer. An employer, other than a host employer, that performs work covered by this section under contract.

Covered conductor. A conductor covered with a dielectric having no rated insulating strength or having a rated insulating strength less than the voltage of the circuit in which the conductor is used.

Current-carrying part. A conducting part intended to be connected in an electric circuit to a source of voltage. Non-currentcarrying parts are those not intended to be so connected.

Deenergized. Free from any electrical connection to a source of potential difference and from electric charge; not having a potential that is different from the potential of the earth.

Note to the definition of "deenergized”: The term applies only to current-carrying parts, which are sometimes energized (alive).

Note to the definition of "enclosed space”: The Occupational Safety and Health Administration does not consider spaces that are enclosed but not designed for employee entry under normal operating conditions to be enclosed spaces for the purposes of this section. Similarly, the Occupational Safety and Health Administration does not consider spaces that are enclosed and that are expected to contain a hazardous atmosphere to be enclosed spaces for the purposes of this section. Such spaces meet the definition of permit spaces in §1910.146, and entry into them must conform to that standard.

Energized (alive, live). Electrically connected to a source of potential difference, or electrically charged so as to have a potential significantly different from that of earth in the vicinity.

Energy isolating device. A physical device that prevents the transmission or release of energy, including, but not limited to, the following: a manually operated electric circuit breaker, a disconnect switch, a manually operated switch, a slide gate, a slip blind, a line valve, blocks, and any similar device with a visible indication of the position of the device. (Push buttons, selector switches, and other control-circuit-type devices are not energy isolating devices.)

Energy source. Any electrical, mechanical, hydraulic, pneumatic, chemical, nuclear, thermal, or other energy source that could cause injury to employees.

Entry (as used in paragraph (e) of this section). The action by which a person passes through an opening into an enclosed space. Entry includes ensuing work activities in that space and is considered to have occurred as soon as any part of the entrant's body breaks the plane of an opening into the space.

Equipment (electric). A general term including material, fittings, devices, appliances, fixtures, apparatus, and the like used as part of or in connection with an electrical installation.

Exposed, Exposed to contact (as applied to energized parts).

Not isolated or guarded.

Fall restraint system. A fall protection system that prevents the user from falling any distance.

First-aid training. Training in the initial care, including cardiopulmonary resuscitation (which includes chest compressions, rescue breathing, and, as appropriate, other heart and lung resuscitation techniques), performed by a person who is not a medical practitioner, of a sick or injured person until definitive medical treatment can be administered.

Ground. A conducting connection, whether planned or unplanned, between an electric circuit or equipment and the earth, or to some conducting body that serves in place of the earth.

Grounded. Connected to earth or to some conducting body that serves in place of the earth.

Guarded. Covered, fenced, enclosed, or otherwise protected, by means of suitable covers or casings, barrier rails or screens, mats, or platforms, designed to minimize the possibility, under normal conditions, of dangerous approach or inadvertent contact by persons or objects.

Note to the definition of "guarded”: Wires that are insulated, but not otherwise protected, are not guarded.

Hazardous atmosphere. An atmosphere that may expose employees to the risk of death, incapacitation, impairment of ability to selfrescue (that is, escape unaided from an enclosed space), injury, or acute illness from one or more of the following causes: (1) Flammable gas, vapor, or mist in excess of 10 percent of its lower flammable limit (LFL); (2) Airborne combustible dust at a concentration that meets or exceeds its LFL; Note to the definition of "hazardous atmosphere” (2): This concentration may be approximated as a condition in which the dust obscures vision at a distance of 1.52 meters (5 feet) or less.

(3) Atmospheric oxygen concentration below 19.5 percent or above 23.5 percent; (4) Atmospheric concentration of any substance for which a dose or a permissible exposure limit is published in Subpart G, Occupational Health and Environmental Control, or in Subpart Z, Toxic and Hazardous Substances, of this part and which could result in employee exposure in excess of its dose or permissible exposure limit; Note to the definition of "hazardous atmosphere” (4): An atmospheric concentration of any substance that is not capable of causing death, incapacitation, impairment of ability to self-rescue, injury, or acute illness due to its health effects is not covered by this provision.

(5) Any other atmospheric condition that is immediately dangerous to life or health.

 Note to the definition of “hazardous atmosphere” (5): For air contaminants for which the Occupational Safety and Health Administration has not determined a dose or permissible exposure limit, other sources of information, such as Safety Data Sheets (SDS) that comply with the Hazard Communication Standard, §1910.1200, published information, and internal documents can provide guidance in establishing acceptable atmospheric conditions.

High-power tests. Tests in which the employer uses fault currents, load currents, magnetizing currents, and line-dropping currents to test equipment, either at the equipment's rated voltage or at lower voltages.

High-voltage tests. Tests in which the employer uses voltages of approximately 1,000 volts as a practical minimum and in which the voltage source has sufficient energy to cause injury.

High wind. A wind of such velocity that one or more of the following hazards would be present: (1) The wind could blow an employee from an elevated location, (2) The wind could cause an employee or equipment handling material to lose control of the material, or (3) The wind would expose an employee to other hazards not controlled by the standard involved.

Note to the definition of "high wind”: The Occupational Safety and Health Administration normally considers winds exceeding 64.4 kilometers per hour (40 miles per hour), or 48.3 kilometers per hour (30 miles per hour) if the work involves material handling, as meeting this criteria, unless the employer takes precautions to protect employees from the hazardous effects of the wind.

Host employer. An employer that operates, or that controls the operating procedures for, an electric power generation, transmission, or distribution installation on which a contract employer is performing work covered by this section.

Note to the definition of "host employer”: The Occupational Safety and Health Administration will treat the electric utility or the owner of the installation as the host employer if it operates or controls operating procedures for the installation. If the electric utility or installation owner neither operates nor controls operating procedures for the installation, the Occupational Safety and Health Administration will treat the employer that the utility or owner has contracted with to operate or control the operating procedures for the installation as the host employer. In no case will there be more than one host employer.

Immediately dangerous to life or health (IDLH). Any condition that poses an immediate or delayed threat to life or that would cause irreversible adverse health effects or that would interfere with an individual's ability to escape unaided from a permit space.

Note to the definition of "immediately dangerous to life or health”: Some materials — hydrogen fluoride gas and cadmium vapor, for example — may produce immediate transient effects that, even if severe, may pass without medical attention, but are followed by sudden, possibly fatal collapse 12-72 hours after exposure. The victim "feels normal” from recovery from transient effects until collapse. Such materials in hazardous quantities are considered to be "immediately” dangerous to life or health.

Insulated. Separated from other conducting surfaces by a dielectric (including air space) offering a high resistance to the passage of current.

Note to the definition of "insulated": When any object is said to be insulated, it is understood to be insulated for the conditions to which it normally is subjected. Otherwise, it is, for the purpose of this section, uninsulated.

Insulation (cable). Material relied upon to insulate the conductor from other conductors or conducting parts or from ground.

Isolated. Not readily accessible to persons unless special means for access are used.

Line-clearance tree trimmer. An employee who, through related training or on-the-job experience or both, is familiar with the special techniques and hazards involved in line-clearance tree trimming.

99

R Special Industries

Designated employee (designated person). An employee (or person) who is assigned by the employer to perform specific duties under the terms of this section and who has sufficient knowledge of the construction and operation of the equipment, and the hazards involved, to perform his or her duties safely.

Electric line truck. A truck used to transport personnel, tools, and material for electric supply line work.

Electric supply equipment. Equipment that produces, modifies, regulates, controls, or safeguards a supply of electric energy.

Electric supply lines. (See Lines; (2) Electric supply lines.)

Electric utility. An organization responsible for the installation, operation, or maintenance of an electric supply system.

Enclosed space. A working space, such as a manhole, vault, tunnel, or shaft, that has a limited means of egress or entry, that is designed for periodic employee entry under normal operating conditions, and that, under normal conditions, does not contain a hazardous atmosphere, but may contain a hazardous atmosphere under abnormal conditions.

§1910.269(x)

Appendix A

Subpart R – Special Industries

Note 1 to the definition of "line-clearance tree trimmer”: An employee who is regularly assigned to a line-clearance tree-trimming crew and who is undergoing on-the-job training and who, in the course of such training, has demonstrated an ability to perform duties safely at his or her level of training and who is under the direct supervision of a line-clearance tree trimmer is considered to be a line-clearance tree trimmer for the performance of those duties.

Note 2 to the definition of "line-clearance tree trimmer”: A line-clearance tree trimmer is not considered to be a "qualified employee” under this section unless he or she has the training required for a qualified employee under paragraph (a)(2)(ii) of this section. However, under the electrical safety-related work practices standard in Subpart S of this part, a line-clearance tree trimmer is considered to be a "qualified employee.” Tree trimming performed by such "qualified employees” is not subject to the electrical safety-related work practice requirements contained in §§1910.331 through 1910.335 when it is directly associated with electric power generation, transmission, or distribution lines or equipment. (See §1910.331 for requirements on the applicability of the electrical safetyrelated work practice requirements contained in §§1910.331 through 1910.335 to lineclearance tree trimming performed by such "qualified employees,” and see the note following §1910.332(b)(3) for information regarding the training an employee must have to be considered a qualified employee under §§1910.331 through 1910.335.)

Line-clearance tree trimming. The pruning, trimming, repairing, maintaining, removing, or clearing of trees, or the cutting of brush, that is within the following distance of electric supply lines and equipment: (1) For voltages to ground of 50 kilovolts or less — 3.05 meters (10 feet); (2) For voltages to ground of more than 50 kilovolts — 3.05 meters (10 feet) plus 0.10 meters (4 inches) for every 10 kilovolts over 50 kilovolts.

Note to the definition of "line-clearance tree trimming”: This section applies only to lineclearance tree trimming performed for the purpose of clearing space around electric power generation, transmission, or distribution lines or equipment and on behalf of an organization that operates, or that controls the operating procedures for, those lines or equipment. See paragraph (a)(1) of this section. Tree trimming performed on behalf of a homeowner or commercial entity other than an organization that operates, or that controls the operating procedures for, electric power generation, transmission, or distribution lines or equipment is not directly associated with an electric power generation, transmission, or distribution installation and is outside the scope of this section. In addition, tree trimming that is not for the purpose of clearing space around electric power generation, transmission, or distribution lines or equipment is not directly associated with an electric power generation, transmission, or distribution installation and is outside the scope of this section. Such tree trimming may be covered by other applicable standards. See, for example, §§1910.268 and 1910.331 through 1910.335.

Lines.

(1) Communication lines. The conductors and their supporting or containing structures which are used for public or private signal or communication service, and which operate at potentials not exceeding 400 volts to ground or 750 volts between any two points of the circuit, and the transmitted power of which does not exceed 150 watts. If the lines are operating at less than 150 volts, no limit is placed on the transmitted power of the system. Under certain conditions, communication cables may include communication circuits exceeding these limitations where such circuits are also used to supply power solely to communication equipment.

Note to the definition of "communication lines”: Telephone, telegraph, railroad signal, data, clock, fire, police alarm, cable television, and other systems conforming to this definition are included. Lines used for signaling purposes, but not included under this definition, are considered as electric supply lines of the same voltage.

(2) Electric supply lines. Conductors used to transmit electric energy and their necessary supporting or containing structures. Signal lines of more than 400 volts are always supply lines within this section, and those of less than 400 volts are considered as supply lines, if so run and operated throughout.

Manhole . A subsurface enclosure that personnel may enter and that is used for installing, operating, and maintaining submersible equipment or cable.

Minimum approach distance . The closest distance an employee may approach an energized or a grounded object.

Note to the definition of "minimum approach distance”: Paragraph (l)(3)(i) of this section requires employers to establish minimum approach distances.

Personal fall arrest system . A system used to arrest an employee in a fall from a working level.

Qualified employee (qualified person) . An employee (person) knowledgeable in the construction and operation of the electric power generation, transmission, and distribution equipment involved, along with the associated hazards.

Note 1 to the definition of "qualified employee (qualified person)”: An employee must have the training required by (a)(2)(ii) of this section to be a qualified employee.

Note 2 to the definition of "qualified employee (qualified person)”: Except under (g)(2)(iv)(C)(2) and (g)(2)(iv)(C)(3) of this section, an employee who is undergoing onthe-job training and who has demonstrated, in the course of such training, an ability to perform duties safely at his or her level of training and who is under the direct supervision of a qualified person is a qualified person for the performance of those duties.

100

Statistical sparkover voltage . A transient overvoltage level that produces a 97.72-percent probability of sparkover (that is, two standard deviations above the voltage at which there is a 50-percent probability of sparkover).

Statistical withstand voltage . A transient overvoltage level that produces a 0.14-percent probability of sparkover (that is, three standard deviations below the voltage at which there is a 50-percent probability of sparkover).

Switch . A device for opening and closing or for changing the connection of a circuit. In this section, a switch is manually operable, unless otherwise stated.

System operator . A qualified person designated to operate the system or its parts.

Vault . An enclosure, above or below ground, that personnel may enter and that is used for installing, operating, or maintaining equipment or cable.

Vented vault . A vault that has provision for air changes using exhaust-flue stacks and low-level air intakes operating on pressure and temperature differentials that provide for airflow that precludes a hazardous atmosphere from developing.

Voltage . The effective (root mean square, or rms) potential difference between any two conductors or between a conductor and ground. This section expresses voltages in nominal values, unless otherwise indicated. The nominal voltage of a system or circuit is the value assigned to a system or circuit of a given voltage class for the purpose of convenient designation. The operating voltage of the system may vary above or below this value.

Work-positioning equipment. A body belt or body harness system rigged to allow an employee to be supported on an elevated vertical surface, such as a utility pole or tower leg, and work with both hands free while leaning.

Appendix A to §1910.269 — Flow ChartsFlowCharts This appendix presents information, in the form of flow charts, that illustrates the scope and application of §1910.269. This appendix addresses the interface between §1910.269 and Subpart S of this Part (Electrical), between §1910.269 and §1910.146 (Permit-required confined spaces), and between §1910.269 and §1910.147 (The control of hazardous energy (lockout/tagout)). These flow charts provide guidance for employers trying to implement the requirements of §1910.269 in combination with other General Industry Standards contained in Part 1910. Employers should always consult the relevant standards, in conjunction with this appendix, to ensure compliance with all applicable requirements.

Appendix A-1 Application of §1910.269 and Subpart S of this Part to the Design of Electrical Installations

Application of §§1910.147, 1910.269 and 1910.333 to Hazardous Energy Appendix A-2 Application of §1910.269 and Subpart S of this Part to Electrical Safety-Related Work Practices1Applicationof§1910.269andSubpartSofthisPart

Appendix A-4

Appendix A-3 Application §1910.269 and Subpart S of this Part to Tree Trimming

NO

Section 1910.269 does not apply.

Subpart S may apply.

Is the work for the purpose of clearing space around electric power generation, transmission, or distribution lines or equipment and on behalf of an NO organization that operates, or that controls the operating procedures for, those lines or equipment?

Section 1910.269 does not apply.

Subpart S may apply.

Is the tree within 3.05 meters (10 feet)I of an overhead power line?

YES

YES

Is the employee a line-clearance tree trimmer as defined in §1910.269(x)?

NO

Subpart S applies. (See §1910.333(c)(3)(i).)

YES

Section 1910.269 applies.

(See §1910.269 (a)(l)(i)(E).)

1

Table 1 — Electrical Safety Requirements in §1910.269

(d), electric-shock hazards only

Appendix A-4 Application of §§1910.147, 1910.269 and 1910.333 to Hazardous Energy Control Procedures (Lockout/Tagout)

Paragraphs that Apply Regardless of Compliance with Subpart S2 (a)(2), (a)(3) and (a)(4).

(h)(3)

(b)

(i)(2) and (i)(3)

(c)

(k)

(d), for other than electric-shock hazards.

(l)(1) through (l)(5), (l)(7), and (l)(10) through (l)(12)

(e)

(m)

(f)

(p)(4)

(g)

(s)(2)

(h)(1) and (h)(2).

(u)(1) and (u)(3) through (u)(5)

(i)(4)

(v)(3) through (v)(5)

(j)

(w)(1) and (w)(7)

(l)(6), (l)(8) and (l)(9).

R

Applicationof§§1910.147,1910.269and1910.333toHazardousEnergy

Special Industries

Compliance with Subpart S Will Comply with These Paragraphs of §1910.2691

3.05 meters (10 feet) plus 0.1 meters (4 inches) for every 10 kilovolts over 50 kilovolts.

(n) (o) (p)(1) through (p)(3). (q) (r) (s)(1) (t) (u)(2) and (u)(6) (v)(1), (v)(2), and (v)(6) through (v)(12). (w)(2) through (w)(6), (w)(8), and (w)(9).

1If the electrical installation meets the requirements of §§1910.302 through 1910.308 of this

part, then the electrical installation and any associated electrical safety-related work practices conforming to §§1910.332 through 1910.335 of this part are considered to comply with these provisions of §1910.269 of this part.

2

These provisions include electrical safety and other requirements that must be met regardless of compliance with Subpart S of this part.

101

Appendix A-5

Subpart R – Special Industries

Appendix A-5 Application of §§1910.146 and 1910.269 to Permit-Required Confined Spaces

Insulated. Separated from other conducting surfaces by a dielectric (including air space) offering a high resistance to the passage of current.

Note to the definition of "insulated": When any object is said to be insulated, it is understood to be insulated for the conditions to which it normally is subjected. Otherwise, it is, for the purpose of this section, uninsulated.

Appendix B to §1910.269 — Working on Exposed Energized PartsWorkingonExposedEnergizedParts I. Introduction Electric utilities design electric power generation, transmission, and distribution installations to meet National Electrical Safety Code (NESC), ANSI C2, requirements. Electric utilities also design transmission and distribution lines to limit line outages as required by system reliability criteria1 and to withstand the maximum overvoltages impressed on the system. Conditions such as switching surges, faults, and lightning can cause overvoltages. Electric utilities generally select insulator design and lengths and the clearances to structural parts so as to prevent outages from contaminated line insulation and during storms. Line insulator lengths and structural clearances have, over the years, come closer to the minimum approach distances used by workers. As minimum approach distances and structural clearances converge, it is increasingly important that system designers and system operating and maintenance personnel understand the concepts underlying minimum approach distances.

The information in this appendix will assist employers in complying with the minimum approach-distance requirements contained in §1910.269(l)(3) and (q)(3). Employers must use the technical criteria and methodology presented in this appendix in establishing minimum approach distances in accordance with §1910.269(l)(3)(i) and Table R-3 and Table R-8. This appendix provides essential background information and technical criteria for the calculation of the required minimum approach distances for live-line work on electric power generation, transmission, and distribution installations.

Unless an employer is using the maximum transient overvoltages specified in Table R-9 for voltages over 72.5 kilovolts, the employer must use persons knowledgeable in the techniques discussed in this appendix, and competent in the field of electric transmission and distribution system design, to determine the maximum transient overvoltage.

II. General A. Definitions. The following definitions from §1910.269(x) relate to work on or near electric power generation, transmission, and distribution lines and equipment and the electrical hazards they present.

Exposed. . . . Not isolated or guarded.

Guarded. Covered, fenced, enclosed, or otherwise protected, by means of suitable covers or casings, barrier rails or screens, mats, or platforms, designed to minimize the possibility, under normal conditions, of dangerous approach or inadvertent contact by persons or objects.

Note to the definition of "guarded”: Wires that are insulated, but not otherwise protected, are not guarded.

1. Federal, State, and local regulatory bodies and electric utilities set reliability requirements that limit the number and duration of system outages.

102

Isolated. Not readily accessible to persons unless special means for access are used.

Statistical sparkover voltage. A transient overvoltage level that produces a 97.72-percent probability of sparkover (that is, two standard deviations above the voltage at which there is a 50-percent probability of sparkover).

Statistical withstand voltage. A transient overvoltage level that produces a 0.14-percent probability of sparkover (that is, three standard deviations below the voltage at which there is a 50-percent probability of sparkover).

B. Installations energized at 50 to 300 volts. The hazards posed by installations energized at 50 to 300 volts are the same as those found in many other workplaces. That is not to say that there is no hazard, but the complexity of electrical protection required does not compare to that required for high-voltage systems. The employee must avoid contact 0with the exposed parts, and the protective equipment used (such as rubber insulating gloves) must provide insulation for the voltages involved.

C. Exposed energized parts over 300 volts AC. Paragraph (l)(3)(i) of §1910.269 requires the employer to establish minimum approach distances no less than the distances computed by Table R-3 for ac systems so that employees can work safely without risk of sparkover.2 Unless the employee is using electrical protective equipment, air is the insulating medium between the employee and energized parts. The distance between the employee and an energized part must be sufficient for the air to withstand the maximum transient overvoltage that can reach the worksite under the working conditions and practices the employee is using. This distance is the minimum air insulation distance, and it is equal to the electrical component of the minimum approach distance.

Normal system design may provide or include a means (such as lightning arrestors) to control maximum anticipated transient overvoltages, or the employer may use temporary devices (portable protective gaps) or measures (such as preventing automatic circuit breaker reclosing) to achieve the same result.

Paragraph (l)(3)(ii) of §1910.269 requires the employer to determine the maximum anticipated per-unit transient overvoltage, phase-to-ground, through an engineering analysis or assume a maximum anticipated per-unit transient overvoltage, phase-toground, in accordance with Table R-9, which specifies the following maximums for ac systems: 72.6 to 420.0 kilovolts — 3.5 per unit 420.1 to 550.0 kilovolts — 3.0 per unit 550.1 to 800.0 kilovolts — 2.5 per unit See paragraph IV.A.2, later in this appendix, for additional discussion of maximum transient overvoltages.

D. Types of exposures. Employees working on or near energized electric power generation, transmission, and distribution systems face two kinds of exposures: Phase-to-ground and phaseto-phase. The exposure is phase-to-ground: (1) With respect to an energized part, when the employee is at ground potential or (2) with respect to ground, when an employee is at the potential of the energized part during live-line barehand work. The exposure is phase-to-phase, with respect to an energized part, when an employee is at the potential of another energized part (at a different potential) during live-line barehand work.

III. Determination of Minimum Approach Distances for AC Voltages Greater Than 300 Volts A. Voltages of 301 to 5,000 volts. Test data generally forms the basis of minimum air insulation distances. The lowest voltage for which sufficient test data exists is 5,000 volts, and these data indicate that the minimum air insulation distance at that voltage is 20 millimeters (1 inch). Because the minimum air insulation distance increases with increasing voltage, and, conversely, decreases with decreasing voltage, an assumed minimum air insulation distance of 20 millimeters will protect against sparkover at voltages of 301 to 5,000 volts. Thus, 20 millimeters is the electrical component of the minimum approach distance for these voltages.

B. Voltages of 5.1 to 72.5 kilovolts. For voltages from 5.1 to 72.5 kilovolts, the Occupational Safety and Health Administration bases the methodology for calculating the electrical component of the minimum approach distance on Institute of Electrical and Electronic Engineers (IEEE) Standard 4-1995,

2. Sparkover is a disruptive electric discharge in which an electric arc forms and electric current passes through air.

Working on Exposed Energized Parts Standard Techniques for High-Voltage Testing. Table 1 lists the critical sparkover distances from that standard as listed in IEEE Std 516-2009, IEEE Guide for Maintenance Methods on Energized Power Lines.

C. Voltages of 72.6 to 800 kilovolts. For voltages of 72.6 kilovolts to 800 kilovolts, this section bases the electrical component of minimum approach distances, before the application of any altitude correction factor, on the following formula: Equation 1 — For Voltages of 72.6 kV to 800 kV

Table 1 — Sparkover Distance for Rod-to-Rod Gap 60 Hz Rod-to-Rod sparkover (kV peak)

Gap spacing from IEEE Std 4-1995 (cm)

25

2

36

3

46

4

53

5

60

6

70

8

79

10

86

12

95

14

104

16

112

18

120

20

143

25

167

30

192

35

218

40

243

45

270

50

322

60

D = 0.3048(C + a) VL-GT Where:

Table 2 — Calculating the Electrical Component of MAD 751 V to 72.5 kV Step

Maximum system phase-to-phase voltage (kV)

Table 3 — Equations for Calculating the Surge Factor, a Phase-to-ground exposures VPeak = TL-GVL-G 2 a

635 kV or less

635.1 to 915 kV

915.1 to 1,050 kV

0

(VPeak-635)/ 140,000

(VPeak-645)/ 135,000

More than 1,050 kV

VPeak = TL-GVL-G2

(VPeak-675)/ 125,000

a

Phase-to-phase exposures1 VPeak = (1.35TL-G + 0.45)VL-G2 a VPeak = (1.35TL-G + 0.45)VL-G2 a

630 kV or less

630.1 to 848 kV

848.1 to 1,131 kV

0

(VPeak-630)/ 155,000

(VPeak-633.6)/ 152,207

1,131.1 to 1,485 kV

More than 1,485 kV

(VPeak-628)/ 153,846

(VPeak-350.5)/ 203,666

1 Use the equations for phase-to-ground exposures (with VPeak for phase-to-phase exposures) unless the employer can demonstrate that no insulated tool spans the gap and that no large conductive object is in the gap.

In Equation 1, T is the maximum transient overvoltage factor in per unit. As noted earlier, §1910.269(l)(3)(ii) requires the employer to determine the maximum anticipated per-unit transient overvoltage, phase-to-ground, through an engineering analysis or assume a maximum anticipated per-unit transient overvoltage, phase-to-ground, in accordance with Table R-9.

For phase-to-ground exposures, the employer uses this value, called TL-G, as T in Equation 1. IEEE Std 516-2009 provides the following formula to calculate the phase-to-phase maximum transient overvoltage, TL-L, from TL-G:

15

36

46

72.5

1. Divide by 3

8.7

20.8

26.6

41.9

2. Multiply by 2

12.2

29.4

37.6

59.2

3. Multiply by 3.0

36.7

88.2

112.7

177.6

4. Divide by 0.85

43.2

103.7

132.6

208.9

5. Interpolate from Table 1

3+(7.2/10)*1

14+(8.7/9)*2

20+(12.6/23)*5

35+(16.9/26)*5

TL-L = 1.35TL-G + 0.45

3.72

15.93

22.74

38.25

For phase-to-phase exposures, the employer uses this value as T in Equation 1.

Electrical component of MAD (cm)

3. The withstand voltage is the voltage at which sparkover is not likely to occur across a specified distance. It is the voltage taken at the 3 point below the sparkover voltage, assuming that the sparkover curve follows a normal distribution.

4. Test data demonstrates that the saturation factor is greater than 0 at peak voltages of about 630 kilovolts. Systems operating at 345 kilovolts (or maximum system voltages of 362 kilovolts) can have peak maximum transient overvoltages exceeding 630 kilovolts. Table R-3 sets equations for calculating a based on peak voltage.

103

R Special Industries

D = Electrical component of the minimum approach distance in air in meters; C = a correction factor associated with the variation of gap sparkover with voltage; a = A factor relating to the saturation of air at system voltages of 345 kilovolts or higher;4 VL-G = Maximum system line-to-ground rms voltage in kilovolts — it should be the "actual” maximum, or the normal highest voltage for the range (for example, 10 percent above the nominal voltage); and T = Maximum transient overvoltage factor in per unit.

In Equation 1, C is 0.01: (1) For phase-to-ground exposures that the employer can demonstrate consist only of air across the approach distance (gap) and (2) for phase-to-phase exposures if the employer can demonstrate that no insulated tool spans the gap and that no large conductive object is in the gap. Otherwise, C is 0.011.

In Equation 1, the term a varies depending on whether the employee's exposure is phase-to-ground or phase-to-phase and on whether objects are in the gap. The employer must use the equations in Table 3 to calculate a. Sparkover test data with insulation spanning the gap form the basis for the equations for phase-to-ground exposures, and sparkover test data with only air in the gap form the basis for the equations for phase-tophase exposures. The phase-to-ground equations result in slightly higher values of a, and, consequently, produce larger minimum approach distances, than the phase-to-phase equations for the same value of VPeak.

Source: IEEE Std 516-2009.

To use this table to determine the electrical component of the minimum approach distance, the employer must determine the peak phase-to-ground transient overvoltage and select a gap from the table that corresponds to that voltage as a withstand voltage rather than a critical sparkover voltage. To calculate the electrical component of the minimum approach distance for voltages between 5 and 72.5 kilovolts, use the following procedure: 1. Divide the phase-to-phase voltage by the square root of 3 to convert it to a phase-to-ground voltage.

2. Multiply the phase-to-ground voltage by the square root of 2 to convert the rms value of the voltage to the peak phase-toground voltage.

3. Multiply the peak phase-to-ground voltage by the maximum per-unit transient overvoltage, which, for this voltage range, is 3.0, as discussed later in this appendix. This is the maximum phase-to-ground transient overvoltage, which corresponds to the withstand voltage for the relevant exposure.3 4. Divide the maximum phase-to-ground transient overvoltage by 0.85 to determine the corresponding critical sparkover voltage. (The critical sparkover voltage is 3 standard deviations (or 15 percent) greater than the withstand voltage.)

5. Determine the electrical component of the minimum approach distance from Table 1 through interpolation.

Table 2 illustrates how to derive the electrical component of the minimum approach distance for voltages from 5.1 to 72.5 kilovolts, before the application of any altitude correction factor, as explained later.

Appendix B

Appendix B

Subpart R – Special Industries

D. Provisions for inadvertent movement. The minimum approach distance must include an "adder” to compensate for the inadvertent movement of the worker relative to an energized part or the movement of the part relative to the worker. This "adder” must account for this possible inadvertent movement and provide the worker with a comfortable and safe zone in which to work. Employers must add the distance for inadvertent movement (called the "ergonomic component of the minimum approach distance”) to the electrical component to determine the total safe minimum approach distances used in live-line work.

The Occupational Safety and Health Administration based the ergonomic component of the minimum approach distance on response time-distance analysis. This technique uses an estimate of the total response time to a hazardous incident and converts that time to the distance traveled. For example, the driver of a car takes a given amount of time to respond to a "stimulus” and stop the vehicle. The elapsed time involved results in the car's traveling some distance before coming to a complete stop. This distance depends on the speed of the car at the time the stimulus appears and the reaction time of the driver.

In the case of live-line work, the employee must first perceive that he or she is approaching the danger zone. Then, the worker responds to the danger and must decelerate and stop all motion toward the energized part. During the time it takes to stop, the employee will travel some distance. This is the distance the employer must add to the electrical component of the minimum approach distance to obtain the total safe minimum approach distance.

At voltages from 751 volts to 72.5 kilovolts,5 the electrical component of the minimum approach distance is smaller than the ergonomic component. At 72.5 kilovolts, the electrical component is only a little more than 0.3 meters (1 foot). An ergonomic component of the minimum approach distance must provide for all the worker's unanticipated movements. At these voltages, workers generally use rubber insulating gloves; however, these gloves protect only a worker's hands and arms. Therefore, the energized object must be at a safe approach distance to protect the worker's face. In this case, 0.61 meters (2 feet) is a sufficient and practical ergonomic component of the minimum approach distance.

For voltages between 72.6 and 800 kilovolts, employees must use different work practices during energized line work. Generally, employees use live-line tools (hot sticks) to perform work on energized equipment. These tools, by design, keep the energized part at a constant distance from the employee and, thus, maintain the appropriate minimum approach distance automatically.

The location of the worker and the type of work methods the worker is using also influence the length of the ergonomic component of the minimum approach distance. In this higher voltage range, the employees use work methods that more tightly control their movements than when the workers perform work using rubber insulating gloves. The worker, therefore, is farther from the energized line or equipment and must be more precise in his or her movements just to perform the work. For these reasons, this section adopts an ergonomic component of the minimum approach distance of 0.31 m (1 foot) for voltages between 72.6 and 800 kilovolts.

Table 4 summarizes the ergonomic component of the minimum approach distance for various voltage ranges.

Table 4 — Ergonomic Component of Minimum Approach Distance Voltage range (kV) 0.301 to 0.750

Distance m

ft

0.31

1.0

0.751 to 72.5

0.61

2.0

72.6 to 800

0.31

1.0

Note: The employer must add this distance to the electrical component of the minimum approach distance to obtain the full minimum approach distance.

The ergonomic component of the minimum approach distance accounts for errors in maintaining the minimum approach distance (which might occur, for example, if an employee misjudges the length of a conductive object he or she is holding), and for errors in judging the minimum approach distance. The ergonomic component also accounts for inadvertent movements by the employee, such as slipping. In contrast, the working position 5. For voltages of 50 to 300 volts, Table R-3 specifies a minimum approach distance of "avoid contact.” The minimum approach distance for this voltage range contains neither an electrical component nor an ergonomic component.

104

selected to properly maintain the minimum approach distance must account for all of an employee's reasonably likely movements and still permit the employee to adhere to the applicable minimum approach distance. (See Figure 1.) Reasonably likely movements include an employee's adjustments to tools, equipment, and working positions and all movements needed to perform the work. For example, the employee should be able to perform all of the following actions without straying into the minimum approach distance: • Adjust his or her hardhat, • maneuver a tool onto an energized part with a reasonable amount of overreaching or underreaching, • reach for and handle tools, material, and equipment passed to him or her, and • adjust tools, and replace components on them, when necessary during the work procedure.

The training of qualified employees required under §1910.269(a)(2), and the job planning and briefing required under §1910.269(c), must address selection of a proper working position.

Figure 1 — Maintaining the Minimum Approach Distance

E. Miscellaneous correction factors. Changes in the air medium that forms the insulation influences the strength of an air gap. A brief discussion of each factor follows.

1. Dielectric strength of air. The dielectric strength of air in a uniform electric field at standard atmospheric conditions is approximately 3 kilovolts per millimeter.6 The pressure, temperature, and humidity of the air, the shape, dimensions, and separation of the electrodes, and the characteristics of the applied voltage (wave shape) affect the disruptive gradient.

2. Atmospheric effect. The empirically determined electrical strength of a given gap is normally applicable at standard atmospheric conditions (20 °C, 101.3 kilopascals, 11 grams/cubic centimeter humidity). An increase in the density (humidity) of the air inhibits sparkover for a given air gap. The combination of temperature and air pressure that results in the lowest gap sparkover voltage is high temperature and low pressure. This combination of conditions is not likely to occur. Low air pressure, generally associated with high humidity, causes increased electrical strength. An average air pressure generally correlates with low humidity. Hot and dry working conditions normally result in reduced electrical strength. The equations for minimum approach distances in Table R-3 assume standard atmospheric conditions.

3. Altitude. The reduced air pressure at high altitudes causes a reduction in the electrical strength of an air gap. An employer 6. For the purposes of estimating arc length, §1910.269 generally assumes a more conservative dielectric strength of 10 kilovolts per 25.4 millimeters, consistent with assumptions made in consensus standards such as the National Electrical Safety Code (IEEE C2-2012). The more conservative value accounts for variables such as electrode shape, wave shape, and a certain amount of overvoltage.

Working on Exposed Energized Parts Table 6 — Minimum Approach Distances Until December 31, 2014

(continued)

Phase-to-ground exposure

Phase-to-phase exposure

Voltage range phase to phase (kV)

m

ft

m

3.42

11.30

5.50

18.10

765 to 800

4.53

14.90

7.91

26.00

Note: The clear live-line tool distance must equal or exceed the values for the indicated voltage ranges.

Table 7 — Minimum Approach Distances Until March 31, 2015 — 72.6 to 121.0 kV With Overvoltage Factor T (p.u.)

2.0

Phase-to-ground exposure

Table 10 — Minimum Approach Distances Until March 31, 2015 — 169.1 to 242.0 kV With Overvoltage Factor T (p.u.)

ft

500 to 550

Phase-to-phase exposure

m

ft

m

ft

0.74

2.42

1.09

3.58

2.1

0.76

2.50

1.09

3.58

2.2

0.79

2.58

1.12

3.67

2.3

0.81

2.67

1.14

3.75

2.4

0.84

2.75

1.17

3.83

2.5

0.84

2.75

1.19

3.92

2.6

0.86

2.83

1.22

4.00

2.7

0.89

2.92

1.24

4.08

2.8

0.91

3.00

1.24

4.08

2.9

0.94

3.08

1.27

4.17

3.0

0.97

3.17

1.30

4.25

Appendix B

2.0

Phase-to-ground exposure

Phase-to-phase exposure

m

ft

m

ft

1.17

3.83

1.85

6.08

2.1

1.22

4.00

1.91

6.25

2.2

1.24

4.08

1.93

6.33

2.3

1.30

4.25

1.98

6.50

2.4

1.35

4.42

2.01

6.58

2.5

1.37

4.50

2.06

6.75

2.6

1.42

4.67

2.11

6.92

2.7

1.47

4.83

2.13

7.00

2.8

1.50

4.92

2.18

7.17

2.9

1.55

5.08

2.24

7.33

3.0

1.60

5.25

2.29

7.50

Note 1: The employer may apply the distance specified in this table only where the employer determines the maximum anticipated per-unit transient overvoltage by engineering analysis.

(Table 6 applies otherwise.)

Note 2: The distances specified in this table are the air, bare-hand, and live-line tool distances.

Table 11 — Minimum Approach Distances Until March 31, 2015 — 242.1 to 362.0 kV With Overvoltage Factor T (p.u.)

2.0

Phase-to-ground exposure

Phase-to-phase exposure

m

ft

m

ft

1.60

5.25

2.62

8.58

2.1

1.65

5.42

2.69

8.83

2.2

1.75

5.75

2.79

9.17

2.3

1.85

6.08

2.90

9.50

Table 8 — Minimum Approach Distances Until March 31, 2015 — 121.1 to 145.0 kV With Overvoltage Factor

2.4

1.93

6.33

3.02

9.92

2.5

2.03

6.67

3.15

10.33 10.75

T (p.u.)

2.0

Phase-to-ground exposure

Phase-to-phase exposure

m

ft

m

ft

0.84

2.75

1.24

4.08

2.1

0.86

2.83

1.27

4.17

2.2

0.89

2.92

1.30

4.25

2.3

0.91

3.00

1.32

4.33

2.4

0.94

3.08

1.35

4.42

2.5

0.97

3.17

1.37

4.50

2.6

0.99

3.25

1.40

4.58

2.7

1.02

3.33

1.42

4.67

2.8

1.04

3.42

1.45

4.75

2.9

1.07

3.50

1.47

4.83

3.0

1.09

3.58

1.50

4.92

2.6

2.16

7.08

3.28

2.7

2.26

7.42

3.40

11.17

2.8

2.36

7.75

3.53

11.58

2.9

2.49

8.17

3.68

12.08

3.0

2.59

8.50

3.81

12.50

Note 1: The employer may apply the distance specified in this table only where the employer determines the maximum anticipated per-unit transient overvoltage by engineering analysis.

(Table 6 applies otherwise.)

Note 2: The distances specified in this table are the air, bare-hand, and live-line tool distances.

Table 12 — Minimum Approach Distances Until March 31, 2015 — 362.1 to 552.0 kV With Overvoltage Factor T (p.u.)

1.5

Phase-to-ground exposure

Phase-to-phase exposure

m

ft

m

ft

1.83

6.00

2.24

7.33

Note 1: The employer may apply the distance specified in this table only where the employer determines the maximum anticipated per-unit transient overvoltage by engineering analysis.

(Table 6 applies otherwise.)

Note 2: The distances specified in this table are the air, bare-hand, and live-line tool distances.

1.6

1.98

6.50

2.67

8.75

1.7

2.13

7.00

3.10

10.17

1.8

2.31

7.58

3.53

11.58

Table 9 — Minimum Approach Distances Until March 31, 2015 — 145.1 to 169.0 kV With Overvoltage Factor

1.9

2.46

8.08

4.01

13.17

T (p.u.)

2.0

Phase-to-ground exposure

Phase-to-phase exposure

m

ft

m

ft

0.91

3.00

1.42

4.67

2.1

0.97

3.17

1.45

4.75

2.2

0.99

3.25

1.47

4.83

2.3

1.02

3.33

1.50

4.92

2.4

1.04

3.42

1.52

5.00

2.5

1.07

3.50

1.57

5.17

2.6

1.12

3.67

1.60

5.25

2.7

1.14

3.75

1.63

5.33

2.8

1.17

3.83

1.65

5.42

2.9

1.19

3.92

1.68

5.50

3.0

1.22

4.00

1.73

5.67

Note 1: The employer may apply the distance specified in this table only where the employer determines the maximum anticipated per-unit transient overvoltage by engineering analysis.

(Table 6 applies otherwise.)

Note 2: The distances specified in this table are the air, bare-hand, and live-line tool distances.

R Special Industries

Note 1: The employer may apply the distance specified in this table only where the employer determines the maximum anticipated per-unit transient overvoltage by engineering analysis.

(Table 6 applies otherwise.)

Note 2: The distances specified in this table are the air, bare-hand, and live-line tool distances.

2.0

2.67

8.75

4.52

14.83

2.1

2.84

9.33

4.75

15.58

2.2

3.02

9.92

4.98

16.33

2.3

3.20

10.50

5.23

17.17

2.4

3.43

11.25

5.51

18.08

Note 1: The employer may apply the distance specified in this table only where the employer determines the maximum anticipated per-unit transient overvoltage by engineering analysis.

(Table 6 applies otherwise.)

Note 2: The distances specified in this table are the air, bare-hand, and live-line tool distances.

Table 13 — Minimum Approach Distances Until March 31, 2015 — 552.1 to 800.0 kV With Overvoltage Factor T (p.u.)

Phase-to-ground exposure

Phase-to-phase exposure

m

ft

m

ft

2.95

9.67

3.68

12.08

1.6

3.25

10.67

4.42

14.50

1.7

3.56

11.67

5.23

17.17

1.8

3.86

12.67

6.07

19.92

1.5

107

Appendix B

Subpart R – Special Industries

Table 13 — Minimum Approach Distances Until March 31, 2015 — 552.1 to 800.0 kV With Overvoltage Factor (continued) T (p.u.)

Phase-to-ground exposure

Phase-to-phase exposure

m

ft

m

ft

1.9

4.19

13.75

6.99

22.92

2.0

4.55

14.92

7.92

26.00

Note 1: The employer may apply the distance specified in this table only where the employer determines the maximum anticipated per-unit transient overvoltage by engineering analysis.

(Table 6 applies otherwise.)

Note 2: The distances specified in this table are the air, bare-hand, and live-line tool distances.

B. Alternative minimum approach distances. Employers may use the minimum approach distances in Table 14 through Table 21 provided that the employer follows the notes to those tables.

Table 14 — AC Minimum Approach Distances — 72.6 to 121.0 kV T (p.u.)

Phase-to-ground exposure

Phase-to-phase exposure

Table 16 — AC Minimum Approach Distances — 145.1 to 169.0 kV T (p.u.)

1.5

Phase-to-ground exposure

Phase-to-phase exposure

m

ft

m

ft

0.81

2.7

1.05

3.4

1.6

0.84

2.8

1.09

3.6

1.7

0.87

2.9

1.13

3.7

1.8

0.90

3.0

1.17

3.8

1.9

0.94

3.1

1.21

4.0

2.0

0.97

3.2

1.25

4.1

2.1

1.00

3.3

1.29

4.2

2.2

1.03

3.4

1.33

4.4

2.3

1.07

3.5

1.37

4.5

2.4

1.10

3.6

1.41

4.6

2.5

1.13

3.7

1.45

4.8

m

ft

m

ft

1.5

0.67

2.2

0.84

2.8

2.6

1.17

3.8

1.49

4.9

1.6

0.69

2.3

0.87

2.9

2.7

1.20

3.9

1.53

5.0

1.7

0.71

2.3

0.90

3.0

2.8

1.23

4.0

1.57

5.2

1.8

0.74

2.4

0.93

3.1

2.9

1.26

4.1

1.61

5.3

1.9

0.76

2.5

0.96

3.1

3.0

1.30

4.3

1.65

5.4

2.0

0.78

2.6

0.99

3.2

3.1

1.33

4.4

1.70

5.6

2.1

0.81

2.7

1.01

3.3

3.2

1.36

4.5

1.76

5.8

2.2

0.83

2.7

1.04

3.4

3.3

1.39

4.6

1.82

6.0

2.3

0.85

2.8

1.07

3.5

3.4

1.43

4.7

1.88

6.2

2.4

0.88

2.9

1.10

3.6

3.5

1.46

4.8

1.94

6.4

2.5

0.90

3.0

1.13

3.7

2.6

0.92

3.0

1.16

3.8

2.7

0.95

3.1

1.19

3.9

2.8

0.97

3.2

1.22

4.0

2.9

0.99

3.2

1.24

4.1

Table 17 — AC Minimum Approach Distances — 169.1 to 242.0 kV T (p.u.)

Phase-to-ground exposure

Phase-to-phase exposure

m

ft

m

ft

1.5

1.02

3.3

1.37

4.5

3.0

1.02

3.3

1.27

4.2

1.6

1.06

3.5

1.43

4.7

3.1

1.04

3.4

1.30

4.3

1.7

1.11

3.6

1.48

4.9

3.2

1.06

3.5

1.33

4.4

1.8

1.16

3.8

1.54

5.1

1.9

1.21

4.0

1.60

5.2

3.3

1.09

3.6

1.36

4.5

3.4

1.11

3.6

1.39

4.6

2.0

1.25

4.1

1.66

5.4

4.7

2.1

1.30

4.3

1.73

5.7

3.5

1.13

3.7

1.42

Table 15 — AC Minimum Approach Distances — 121.1 to 145.0 kV T (p.u.)

Phase-to-ground exposure

Phase-to-phase exposure

2.2

1.35

4.4

1.81

5.9

2.3

1.39

4.6

1.90

6.2

2.4

1.44

4.7

1.99

6.5

2.5

1.49

4.9

2.08

6.8

m

ft

m

ft

1.5

0.74

2.4

0.95

3.1

2.6

1.53

5.0

2.17

7.1

1.6

0.76

2.5

0.98

3.2

2.7

1.58

5.2

2.26

7.4

1.7

0.79

2.6

1.02

3.3

2.8

1.63

5.3

2.36

7.7

1.8

0.82

2.7

1.05

3.4

2.9

1.67

5.5

2.45

8.0

1.9

0.85

2.8

1.08

3.5

3.0

1.72

5.6

2.55

8.4

2.0

0.88

2.9

1.12

3.7

3.1

1.77

5.8

2.65

8.7

2.1

0.90

3.0

1.15

3.8

3.2

1.81

5.9

2.76

9.1

2.2

0.93

3.1

1.19

3.9

3.3

1.88

6.2

2.86

9.4

2.3

0.96

3.1

1.22

4.0

3.4

1.95

6.4

2.97

9.7

2.4

0.99

3.2

1.26

4.1

3.5

2.01

6.6

3.08

10.1

2.5

1.02

3.3

1.29

4.2

2.6

1.04

3.4

1.33

4.4

2.7

1.07

3.5

1.36

4.5

2.8

1.10

3.6

1.39

4.6

2.9

1.13

3.7

1.43

4.7

3.0

1.16

3.8

1.46

4.8

3.1

1.19

3.9

1.50

4.9

3.2

1.21

4.0

1.53

5.0

3.3

1.24

4.1

1.57

5.2

3.4

1.27

4.2

1.60

5.2

3.5

1.30

4.3

1.64

5.4

108

Table 18 — AC Minimum Approach Distances — 242.1 to 362.0 kV T (p.u.)

1.5

Phase-to-ground exposure

Phase-to-phase exposure

m

ft

m

ft

1.37

4.5

1.99

6.5

1.6

1.44

4.7

2.13

7.0

1.7

1.51

5.0

2.27

7.4

1.8

1.58

5.2

2.41

7.9

1.9

1.65

5.4

2.56

8.4

2.0

1.72

5.6

2.71

8.9

2.1

1.79

5.9

2.87

9.4

Protection From Hazardous Differences in Electric Potential Table 18 — AC Minimum Approach Distances — 242.1 to 362.0 kV T (p.u.)

Phase-to-ground exposure

(continued)

Phase-to-phase exposure

Appendix C

Table 20 — AC Minimum Approach Distances — 420.1 to 550.0 kV T (p.u.)

Phase-to-ground exposure

(continued)

Phase-to-phase exposure

m

ft

m

ft

m

ft

m

ft

2.2

1.87

6.1

3.03

9.9

2.8

4.56

15.0

7.52

24.7

2.3

1.97

6.5

3.20

10.5

2.9

4.81

15.8

7.88

25.9

2.4

2.08

6.8

3.37

11.1

3.0

5.07

16.6

8.24

27.0

2.5

2.19

7.2

3.55

11.6

2.6

2.29

7.5

3.73

12.2

2.7

2.41

7.9

3.91

12.8

2.8

2.52

8.3

4.10

13.5

2.9

2.64

8.7

4.29

14.1

3.0

2.76

9.1

4.49

14.7

3.1

2.88

9.4

4.69

15.4

3.2

3.01

9.9

4.90

16.1

3.3

3.14

10.3

5.11

16.8

3.4

3.27

10.7

5.32

17.5

3.5

3.41

11.2

5.52

18.1

Table 19 — AC Minimum Approach Distances — 362.1 to 420.0 kV T (p.u.)

Phase-to-ground exposure

Phase-to-phase exposure

m

ft

m

ft

1.5

1.53

5.0

2.40

7.9

1.6

1.62

5.3

2.58

8.5

1.7

1.70

5.6

2.75

9.0

1.8

1.78

5.8

2.94

9.6

1.9

1.88

6.2

3.13

10.3

1.99

6.5

3.33

10.9

2.1

2.12

7.0

3.53

11.6

2.2

2.24

7.3

3.74

12.3

2.3

2.37

7.8

3.95

13.0

2.4

2.50

8.2

4.17

13.7

2.5

2.64

8.7

4.40

14.4

2.6

2.78

9.1

4.63

15.2

2.7

2.93

9.6

4.87

16.0

2.8

3.07

10.1

5.11

16.8

2.9

3.23

10.6

5.36

17.6

3.0

3.38

11.1

5.59

18.3

3.1

3.55

11.6

5.82

19.1

3.2

3.72

12.2

6.07

19.9

3.3

3.89

12.8

6.31

20.7

3.4

4.07

13.4

6.56

21.5

3.5

4.25

13.9

6.81

22.3

Table 20 — AC Minimum Approach Distances — 420.1 to 550.0 kV T (p.u.)

1.5

Phase-to-ground exposure

Phase-to-phase exposure

m

ft

m

ft

1.95

6.4

3.46

11.4

1.6

2.11

6.9

3.73

12.2

1.7

2.28

7.5

4.02

13.2

1.8

2.45

8.0

4.31

14.1

1.9

2.62

8.6

4.61

15.1

2.0

2.81

9.2

4.92

16.1

2.1

3.00

9.8

5.25

17.2

2.2

3.20

10.5

5.55

18.2

2.3

3.40

11.2

5.86

19.2

2.4

3.62

11.9

6.18

20.3 21.3

2.5

3.84

12.6

6.50

2.6

4.07

13.4

6.83

22.4

2.7

4.31

14.1

7.18

23.6

T (p.u.)

Phase-to-ground exposure

1.5

Phase-to-phase exposure

m

ft

m

ft

3.16

10.4

5.97

19.6

1.6

3.46

11.4

6.43

21.1

1.7

3.78

12.4

6.92

22.7

1.8

4.12

13.5

7.42

24.3

1.9

4.47

14.7

7.93

26.0

2.0

4.83

15.8

8.47

27.8

2.1

5.21

17.1

9.02

29.6

2.2

5.61

18.4

9.58

31.4

2.3

6.02

19.8

10.16

33.3

2.4

6.44

21.1

10.76

35.3

2.5

6.88

22.6

11.38

37.3

Notes to Table 14 through Table 21: 1. The employer must determine the maximum anticipated per-unit transient overvoltage, phase-to-ground, through an engineering analysis, as required by §1910.269(l)(3)(ii), or assume a maximum anticipated per-unit transient overvoltage, phase-to-ground, in accordance with Table R-9.

2. For phase-to-phase exposures, the employer must demonstrate that no insulated tool spans the gap and that no large conductive object is in the gap.

3. The worksite must be at an elevation of 900 meters (3,000 feet) or less above sea level.

Appendix C to §1910.269 — Protection From Hazardous Differences in Electric PotentialProtectio F nrom HazardoD usifferencin eE slectric Potential I. Introduction Current passing through an impedance impresses voltage across that impedance. Even conductors have some, albeit low, value of impedance. Therefore, if a "grounded”14 object, such as a crane or deenergized and grounded power line, results in a ground fault on a power line, voltage is impressed on that grounded object. The voltage impressed on the grounded object depends largely on the voltage on the line, on the impedance of the faulted conductor, and on the impedance to "true,” or "absolute,” ground represented by the object. If the impedance of the object causing the fault is relatively large, the voltage impressed on the object is essentially the phaseto-ground system voltage. However, even faults to grounded power lines or to well grounded transmission towers or substation structures (which have relatively low values of impedance to ground) can result in hazardous voltages.15 In all cases, the degree of the hazard depends on the magnitude of the current through the employee and the time of exposure. This appendix discusses methods of protecting workers against the possibility that grounded objects, such as cranes and other mechanical equipment, will contact energized power lines and that deenergized and grounded power lines will become accidentally energized.

II. Voltage-Gradient Distribution A. Voltage-gradient distribution curve. Absolute, or true, ground serves as a reference and always has a voltage of 0 volts above ground potential. Because there is an impedance between a grounding electrode and absolute ground, there will be a voltage difference between the grounding electrode and absolute ground under ground-fault conditions. Voltage dissipates from the grounding electrode (or from the grounding point) and creates a ground potential gradient. The voltage decreases rapidly with increasing distance from the grounding electrode. A voltage drop associated with this dissipation of voltage is a ground potential.

Figure 1 is a typical voltage-gradient distribution curve (assuming a uniform soil texture).

14. This appendix generally uses the term "grounded” only with respect to grounding that the employer intentionally installs, for example, the grounding an employer installs on a deenergized conductor. However, in this case, the term "grounded” means connected to earth, regardless of whether or not that connection is intentional.

15. Thus, grounding systems for transmission towers and substation structures should be designed to minimize the step and touch potentials involved.

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R Special Industries

2.0

Table 21 — AC Minimum Approach Distances — 550.1 to 800.0 kV

Appendix C

Subpart R – Special Industries

Figure 2 — Step and Touch Potentials

Figure 1 — Typical Voltage-Gradient Distribution Curve

B. Step and touch potentials. Figure 1 also shows that workers are at risk from step and touch potentials. Step potential is the voltage between the feet of a person standing near an energized grounded object (the electrode). In Figure 1, the step potential is equal to the difference in voltage between two points at different distances from the electrode (where the points represent the location of each foot in relation to the electrode). A person could be at risk of injury during a fault simply by standing near the object.

Touch potential is the voltage between the energized grounded object (again, the electrode) and the feet of a person in contact with the object. In Figure 1, the touch potential is equal to the difference in voltage between the electrode (which is at a distance of 0 meters) and a point some distance away from the electrode (where the point represents the location of the feet of the person in contact with the object). The touch potential could be nearly the full voltage across the grounded object if that object is grounded at a point remote from the place where the person is in contact with it. For example, a crane grounded to the system neutral and that contacts an energized line would expose any person in contact with the crane or its uninsulated load line to a touch potential nearly equal to the full fault voltage.

Figure 2 illustrates step and touch potentials.

110

III. Protecting Workers From Hazardous Differences in Electrical Potential A. Definitions. The following definitions apply to section III of this appendix: Bond. The electrical interconnection of conductive parts designed to maintain a common electric potential.

Bonding cable (bonding jumper). A cable connected to two conductive parts to bond the parts together.

Cluster bar. A terminal temporarily attached to a structure that provides a means for the attachment and bonding of grounding and bonding cables to the structure.

Ground. A conducting connection between an electric circuit or equipment and the earth, or to some conducting body that serves in place of the earth.

Grounding cable (grounding jumper). A cable connected between a deenergized part and ground. Note that grounding cables carry fault current and bonding cables generally do not.

A cable that bonds two conductive parts but carries substantial fault current (for example, a jumper connected between one phase and a grounded phase) is a grounding cable.

Ground mat (grounding grid). A temporarily or permanently installed metallic mat or grating that establishes an equipotential surface and provides connection points for attaching grounds.

B. Analyzing the hazard. The employer can use an engineering analysis of the power system under fault conditions to determine whether hazardous step and touch voltages will develop.

The analysis should determine the voltage on all conductive objects in the work area and the amount of time the voltage will be present. Based on the this analysis, the employer can select appropriate measures and protective equipment, including the measures and protective equipment outlined in Section III of this appendix, to protect each employee from hazardous differences in electric potential. For example, from the analysis, the employer will know the voltage remaining on conductive objects after employees install bonding and grounding equipment and will be able to select insulating equipment with an appropriate rating, as described in paragraph III.C.2 of this appendix.

C. Protecting workers on the ground. The employer may use several methods, including equipotential zones, insulating equipment, and restricted work areas, to protect employees on the ground from hazardous differences in electrical potential.

1. An equipotential zone will protect workers within it from hazardous step and touch potentials. (See Figure 3.) Equipotential zones will not, however, protect employees located either wholly or partially outside the protected area. The employer can establish an equipotential zone for workers on the ground, with respect to a grounded object, through the use of a metal mat connected to the grounded object. The employer can use a grounding grid to equalize the voltage within the grid or bond conductive objects in the immediate work area to minimize the potential between the objects and between each object and ground. (Bonding an object outside the work area can increase the touch potential to that object, however.) Section III.D of this appendix discusses equipotential zones for employees working on deenergized and grounded power lines.

Protection From Hazardous Differences in Electric Potential 2. Insulating equipment, such as rubber gloves, can protect employees handling grounded equipment and conductors from hazardous touch potentials. The insulating equipment must be rated for the highest voltage that can be impressed on the grounded objects under fault conditions (rather than for the full system voltage).

3. Restricting employees from areas where hazardous step or touch potentials could arise can protect employees not directly involved in performing the operation. The employer must ensure that employees on the ground in the vicinity of transmission structures are at a distance where step voltages would be insufficient to cause injury. Employees must not handle grounded conductors or equipment likely to become energized to hazardous voltages unless the employees are within an equipotential zone or protected by insulating equipment.

Appendix C

determine whether any differences in electric potential to which workers could be exposed are hazardous as part of the demonstration required by §1910.269(n)(3).

Institute of Electrical and Electronic Engineers (IEEE) Standard 1048-2003, IEEE Guide for Protective Grounding of Power Lines, provides the following equation for determining the threshold of ventricular fibrillation when the duration of the electric shock is limited:

16. The protective grounding required by §1910.269(n) limits to safe values the potential differences between accessible objects in each employee's work environment. Ideally, a protective grounding system would create a true equipotential zone in which every point is at the same electric potential. In practice, current passing through the grounding and bonding elements creates potential differences. If these potential differences are hazardous, the employer may not treat the zone as an equipotential zone.

17. Electric current passing through the body has varying effects depending on the amount of the current. At the let-go threshold, the current overrides a person's control over his or her muscles. At that level, an employee grasping an object will not be able to let go of the object. The let-go threshold varies from person to person; however, the recognized value for workers is 6 milliamperes.

Energized Grounded Object

Voltage Distribution Curve

Step and Touch Potential Zone

Equipotential Zone (See text.)

Figure 3 — Protection from Ground-Potential Gradients

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R Special Industries

D. Protecting employees working on deenergized and grounded power lines. This Section III.D of Appendix C establishes guidelines to help employers comply with requirements in §1910.269(n) for using protective grounding to protect employees working on deenergized power lines. Paragraph (n) of §1910.269 applies to grounding of transmission and distribution lines and equipment for the purpose of protecting workers.

Paragraph (n)(3) of §1910.269 requires temporary protective grounds to be placed at such locations and arranged in such a manner that the employer can demonstrate will prevent exposure of each employee to hazardous differences in electric potential.16 Sections III.D.1 and III.D.2 of this appendix provide guidelines that employers can use in making the demonstration required by §1910.269(n)(3). Section III.D.1 of this appendix provides guidelines on how the employer can determine whether particular grounding practices expose employees to hazardous differences in electric potential. Section III.D.2 of this appendix describes grounding methods that the employer can use in lieu of an engineering analysis to make the demonstration required by §1910.269(n)(3). The Occupational Safety and Health Administration will consider employers that comply with the criteria in this appendix as meeting §1910.269(n)(3).

Finally, Section III.D.3 of this appendix discusses other safety considerations that will help the employer comply with other requirements in §1910.269(n). Following these guidelines will protect workers from hazards that can occur when a deenergized and grounded line becomes energized.

1. Determining safe body current limits. This Section III.D.1 of Appendix C provides guidelines on how an employer can

where I is the current through the worker's body, and t is the duration of the current in seconds. This equation represents the ventricular fibrillation threshold for 95.5 percent of the adult population with a mass of 50 kilograms (110 pounds) or more. The equation is valid for current durations between 0.0083 to 3.0 seconds.

To use this equation to set safe voltage limits in an equipotential zone around the worker, the employer will need to assume a value for the resistance of the worker's body. IEEE Std 10482003 states that "total body resistance is usually taken as 1000  for determining . . . body current limits.” However, employers should be aware that the impedance of a worker's body can be substantially less than that value. For instance, IEEE Std 1048-2003 reports a minimum hand-to-hand resistance of 610 ohms and an internal body resistance of 500 ohms. The internal resistance of the body better represents the minimum resistance of a worker's body when the skin resistance drops near zero, which occurs, for example, when there are breaks in the worker's skin, for instance, from cuts or from blisters formed as a result of the current from an electric shock, or when the worker is wet at the points of contact.

Employers may use the IEEE Std 1048-2003 equation to determine safe body current limits only if the employer protects workers from hazards associated with involuntary muscle reactions from electric shock (for example, the hazard to a worker from falling as a result of an electric shock). Moreover, the equation applies only when the duration of the electric shock is limited. If the precautions the employer takes, including those required by applicable standards, do not adequately protect employees from hazards associated with involuntary reactions from electric shock, a hazard exists if the induced voltage is sufficient to pass a current of 1 milliampere through a 500-ohm resistor. (The 500-ohm resistor represents the resistance of an employee. The 1-milliampere current is the threshold of perception.) Finally, if the employer protects employees from injury due to involuntary reactions from electric shock, but the duration of the electric shock is unlimited (that is, when the fault current at the work location will be insufficient to trip the devices protecting the circuit), a hazard exists if the resultant current would be more than 6 milliamperes (the recognized let-go threshold for workers17).

2. Acceptable methods of grounding for employers that do not perform an engineering determination. The grounding methods presented in this section of this appendix ensure that differences in electric potential are as low as possible and, therefore, meet §1910.269(n)(3) without an engineering determination of the potential differences. These methods follow two principles: (i) The grounding method must ensure that the circuit opens in the fastest available clearing time, and (ii) the grounding method must ensure that the potential differences between conductive objects in the employee's work area are as low as possible.

Paragraph (n)(3) of §1910.269 does not require grounding methods to meet the criteria embodied in these principles. Instead, the paragraph requires that protective grounds be "placed at such locations and arranged in such a manner that the employer can demonstrate will prevent exposure of each employee to hazardous differences in electric potential.” However, when the employer's grounding practices do not follow these two principles, the employer will need to perform an engineering analysis to make the demonstration required by §1910.269(n)(3).

Appendix C

Subpart R – Special Industries i. Ensuring that the circuit opens in the fastest available clearing time. Generally, the higher the fault current, the shorter the clearing times for the same type of fault. Therefore, to ensure the fastest available clearing time, the grounding method must maximize the fault current with a low impedance connection to ground. The employer accomplishes this objective by grounding the circuit conductors to the best ground available at the worksite. Thus, the employer must ground to a grounded system neutral conductor, if one is present. A grounded system neutral has a direct connection to the system ground at the source, resulting in an extremely low impedance to ground. In a substation, the employer may instead ground to the substation grid, which also has an extremely low impedance to the system ground and, typically, is connected to a grounded system neutral when one is present. Remote system grounds, such as pole and tower grounds, have a higher impedance to the system ground than grounded system neutrals and substation grounding grids; however, the employer may use a remote ground when lower impedance grounds are not available. In the absence of a grounded system neutral, substation grid, and remote ground, the employer may use a temporary driven ground at the worksite.

In addition, if employees are working on a threephase system, the grounding method must short circuit all three phases. Short circuiting all phases will ensure faster clearing and lower the current through the grounding cable connecting the deenergized line to ground, thereby lowering the voltage across that cable. The short circuit need not be at the worksite; however, the employer must treat any conductor that is not grounded at the worksite as energized because the ungrounded conductors will be energized at fault voltage during a fault. ii. Ensuring that the potential differences between conductive objects in the employee's work area are as low as possible. To achieve as low a voltage as possible across any two conductive objects in the work area, the employer must bond all conductive objects in the work area. This section of this appendix discusses how to create a zone that minimizes differences in electric potential between conductive objects in the work area.

The employer must use bonding cables to bond conductive objects, except for metallic objects bonded through metal-to-metal contact. The employer must ensure that metal-to-metal contacts are tight and free of contamination, such as oxidation, that can increase the impedance across the connection. For example, a bolted connection between metal lattice tower members is acceptable if the connection is tight and free of corrosion and other contamination.

Figure 4 shows how to create an equipotential zone for metal lattice towers.

Wood poles are conductive objects. The poles can absorb moisture and conduct electricity, particularly at distribution and transmission voltages. Consequently, the employer must either: (1) Provide a conductive platform, bonded to a grounding cable, on which the worker stands or (2) use cluster bars to bond wood poles to the grounding cable. The employer must ensure that employees install the cluster bar below, and close to, the worker's feet.

The inner portion of the wood pole is more conductive than the outer shell, so it is important that the cluster bar be in conductive contact with a metal spike or nail that penetrates the wood to a depth greater than or equal to the depth the worker's climbing gaffs will penetrate the wood. For example, the employer could mount the cluster bar on a bare pole ground wire fastened to the pole with nails or staples that penetrate to the required depth. Alternatively, the employer may temporarily nail a conductive strap to the pole and connect the strap to the cluster bar. Figure 5 shows how to create an equipotential zone for wood poles.

112

Notes: 1. Employers must ground overhead ground wires that are within reach of the employee.

2. The grounding cable must be as short as practicable; therefore, the attachment points between the grounding cable and the tower may be different from that shown in the figure.

Figure 4 — Equipotential Zone for Metal Lattice Tower

Figure 5 — Equipotential Grounding for Wood Poles

For underground systems, employers commonly install grounds at the points of disconnection of the underground cables. These grounding points are typically remote from the manhole or underground vault where employees will be working on the cable. Workers in contact with a cable grounded at a remote location can experience hazardous potential differences if the cable becomes energized or if a fault occurs on a different, but nearby, energized cable. The fault current causes potential gradients in the earth, and a potential difference will exist between the earth where the worker is standing and the earth where the cable is grounded.

Consequently, to create an equipotential zone for the worker, the employer must provide a means of connecting the deenergized cable to ground at the worksite by having the worker stand on a conductive mat bonded to the deenergized cable. If the cable is cut, the employer must install a bond across the opening in the cable or install one bond on each side of the opening to ensure that the separate cable ends are at the same potential. The employer must protect the worker from any hazardous differences in potential any

Subpart V – Power Transmission and Distribution Subpart V –  Power Transmission and DistributionPow er Tr ansm i ssi on and D i st r i but i on §1926.950  General (a) Application. [§1926.950(a)] (1) Scope. [§1926.950(a)(1)] (i) This subpart, except for paragraph (a)(3) of this section, covers the construction of electric power transmission and distribution lines and equipment. As used in this subpart, the term “construction” includes the erection of new electric transmission and distribution lines and equipment, and the alteration, conversion, and improvement of existing electric transmission and distribution lines and equipment. [§1926.950(a)(1)(i)] Note to paragraph (a)(1)(i): An employer that complies with §1910.269 of this chapter will be considered in compliance with requirements in this subpart that do not reference other subparts of this part. Compliance with §1910.269 of this chapter will not excuse an employer from compliance obligations under other subparts of this part.

[§1926.950(b)(2)(i)]

(ii) The skills and techniques necessary to determine the nominal voltage of exposed live parts, [§1926.950(b)(2)(ii)] (iii) The minimum approach distances specified in this subpart corresponding to the voltages to which the qualified employee will be exposed and the skills and techniques necessary to maintain those distances, [§1926.950(b)(2)(iii)] (iv) The proper use of the special precautionary techniques, personal protective equipment, insulating and shielding materials, and insulated tools for working on or near exposed energized parts of electric equipment, and [§1926.950(b)(2)(iv)]

(v) The recognition of electrical hazards to which the employee may be exposed and the skills and techniques necessary to control or avoid these hazards. [§1926.950(b)(2)(v)] Note to paragraph (b)(2): For the purposes of this subpart, a person must have the training required by paragraph (b)(2) of this section to be considered a qualified person.

(3) Supervision and annual inspection. The employer shall determine, through regular supervision and through inspections conducted on at least an annual basis, that each employee is complying with the safety-related work practices required by this subpart. [§1926.950(b)(3)] (4) Additional training. An employee shall receive additional training (or retraining) under any of the following conditions: [§1926.950(b)(4)]

(i) If the supervision or annual inspections required by paragraph (b)(3) of this section indicate that the employee is not

complying with the safety-related work practices required by this subpart, or [§1926.950(b)(4)(i)] (ii) If new technology, new types of equipment, or changes in procedures necessitate the use of safety-related work practices that are different from those which the employee would normally use, or [§1926.950(b)(4)(ii)] (iii) If he or she must employ safety-related work practices that are not normally used during his or her regular job duties. [§1926.950(b)(4)(iii)] Note to paragraph (b)(4)(iii): The Occupational Safety and Health Administration considers tasks that are performed less often than once per year to necessitate retraining before the performance of the work practices involved.

(5) Type of training. The training required by paragraph (b) of this section shall be of the classroom or on-the-job type. [§1926.950(b)(5)]

(6) Training goals. The training shall establish employee proficiency in the work practices required by this subpart and shall introduce the procedures necessary for compliance with this subpart. [§1926.950(b)(6)] (7) Demonstration of proficiency. The employer shall ensure that each employee has demonstrated proficiency in the work practices involved before that employee is considered as having completed the training required by paragraph (b) of this section. [§1926.950(b)(7)] Note 1 to paragraph (b)(7): Though they are not required by this paragraph, employment records that indicate that an employee has successfully completed the required training are one way of keeping track of when an employee has demonstrated proficiency.

Note 2 to paragraph (b)(7): For an employee with previous training, an employer may determine that that employee has demonstrated the proficiency required by this paragraph using the following process: (1) Confirm that the employee has the training required required by paragraph (b) of this section, (2) use an examination or interview to make an initial determination that the employee understands the relevant safety-related work practices before he or she performs any work covered by this subpart, and (3) supervise the employee closely until that employee has demonstrated proficiency as required by this paragraph. (c)  Information transfer. [§1926.950(c)]

(1) Host employer responsibilities. Before work begins, the host employer shall inform contract employers of: [§1926.950(c)(1)] (i) The characteristics of the host employer's installation that are related to the safety of the work to be performed and are listed in paragraphs (d)(1) through (d)(5) of this section; [§1926.950(c)(1)(i)] Note to paragraph (c)(1)(i): This paragraph requires the host employer to obtain information listed in paragraphs (d)(1) through (d)(5) of this section if it does not have this information in existing records.

(ii) Conditions that are related to the safety of the work to be performed, that are listed in paragraphs (d)(6) through (d)(8) of this section, and that are known to the host employer; [§1926.950(c)(1)(ii)] Note to paragraph (c)(1)(ii): For the purposes of this paragraph, the host employer need only provide information to contract employers that the host employer can obtain from its existing records through the exercise of reasonable diligence. This paragraph does not require the host employer to make inspections of worksite conditions to obtain this information.

(iii) Information about the design and operation of the host employer's installation that the contract employer needs to make the assessments required by this subpart; and [§1926.950(c)(1)(iii)] Note to paragraph (c)(1)(iii): This paragraph requires the host employer to obtain information about the design and operation of its installation that contract employers need to make required assessments if it does not have this information in existing records.

(iv) Any other information about the design and operation of the host employer's installation that is known by the host employer, that the contract employer requests, and that is related to the protection of the contract employer's employees. [§1926.950(c)(1)(iv)] Note to paragraph (c)(1)(iv): For the purposes of this paragraph, the host employer need only provide information to contract employers that the host employer can obtain from its existing records through the exercise of reasonable diligence. This paragraph does not require the host employer to make inspections of worksite conditions to obtain this information.

(2) Contract employer responsibilities. [§1926.950(c)(2)]

(i) The contract employer shall ensure that each of its employees is instructed in the hazardous conditions relevant to the employee's work that the contract employer is aware of as a result of information communicated to the contract employer by the host employer under paragraph (c)(1) of this section. [§1926.950(c)(2)(i)] (ii) Before work begins, the contract employer shall advise the host employer of any unique hazardous conditions presented by the contract employer's work. [§1926.950(c)(2)(ii)] (iii) The contract employer shall advise the host employer of any unanticipated hazardous conditions found during the contract employer's work that the host employer did not mention under paragraph (c)(1) of this section. The contract employer shall provide this information to the host

125

V Power Transmission and Distribution

(ii) Notwithstanding paragraph (a)(1)(i) of this section, this subpart does not apply to electrical safety-related work practices for unqualified employees. [§1926.950(a)(1)(ii)] (2) Other Part 1926 standards. This subpart applies in addition to all other applicable standards contained in this Part 1926.

Employers covered under this subpart are not exempt from complying with other applicable provisions in Part 1926 by the operation of §1910.5(c) of this chapter. Specific references in this subpart to other sections of Part 1926 are provided for emphasis only. [§1926.950(a)(2)] (3) Applicable part 1910 requirements. [§1926.950(a)(3)] (i) Line-clearance tree trimming performed for the purpose of clearing space around electric power generation, transmission, or distribution lines or equipment and on behalf of an organization that operates, or that controls the operating procedures for, those lines or equipment shall comply with §1910.269 of this chapter. [§1926.950(a)(3)(i)] (ii) Work involving electric power generation installations shall comply with §1910.269 of this chapter. [§1926.950(a)(3)(ii)] (b) Training. [§1926.950(b)] (1) All employees. [§1926.950(b)(1)] (i) Each employee shall be trained in, and familiar with, the safety-related work practices, safety procedures, and other safety requirements in this subpart that pertain to his or her job assignments. [§1926.950(b)(1)(i)] (ii) Each employee shall also be trained in and familiar with any other safety practices, including applicable emergency procedures (such as pole-top and manhole rescue), that are not specifically addressed by this subpart but that are related to his or her work and are necessary for his or her safety. [§1926.950(b)(1)(ii)] (iii) The degree of training shall be determined by the risk to the employee for the hazard involved. [§1926.950(b)(1)(iii)] (2) Qualified employees. Each qualified employee shall also be trained and competent in: [§1926.950(b)(2)] (i) The skills and techniques necessary to distinguish exposed live parts from other parts of electric equipment,

§1926.950(c)

§1926.951

Subpart V – Power Transmission and Distribution

employer within 2 working days after discovering the hazardous condition. [§1926.950(c)(2)(iii)] (3) Joint host- and contract-employer responsibilities. The contract employer and the host employer shall coordinate their work rules and procedures so that each employee of the contract employer and the host employer is protected as required by this subpart. [§1926.950(c)(3)] (d) Existing characteristics and conditions. Existing characteristics and conditions of electric lines and equipment that are related to the safety of the work to be performed shall be determined before work on or near the lines or equipment is started. Such characteristics and conditions include, but are not limited to: [§1926.950(d)]

(1) The nominal voltages of lines and equipment, [§1926.950(d)(1)] (2) The maximum switching-transient voltages, [§1926.950(d)(2)] (3) The presence of hazardous induced voltages, [§1926.950(d)(3)] (4) The presence of protective grounds and equipment grounding conductors, [§1926.950(d)(4)] (5) The locations of circuits and equipment, including electric supply lines, communication lines, and fire-protective signaling circuits, [§1926.950(d)(5)]

(6) The condition of protective grounds and equipment grounding conductors, [§1926.950(d)(6)] (7) The condition of poles, and [§1926.950(d)(7)] (8) Environmental conditions relating to safety. [§1926.950(d)(8)] [44 FR 8577, Feb. 9, 1979; 44 FR 20940, Apr. 6, 1979, as amended at 80 FR 60040, Oct. 5, 2015]

§1926.951  Medical services and first aid (a) General. The employer shall provide medical services and first aid as required in §1926.50. [§1926.951(a)] (b)  First-aid training. In addition to the requirements of §1926.50, when employees are performing work on, or associated with, exposed lines or equipment energized at 50 volts or more, persons with first-aid training shall be available as follows: [§1926.951(b)]

(1)  Field work. For field work involving two or more employees at a work location, at least two trained persons shall be available. [§1926.951(b)(1)] (2)  Fixed work locations. For fixed work locations such as substations, the number of trained persons available shall be sufficient to ensure that each employee exposed to electric shock can be reached within 4 minutes by a trained person. However, where the existing number of employees is insufficient to meet this requirement (at a remote substation, for example), each employee at the work location shall be a trained employee. [§1926.951(b)(2)]

§1926.952  Job briefing (a) Before each job. [§1926.952(a)] (1) Information provided by the employer. In assigning an employee or a group of employees to perform a job, the employer shall provide the employee in charge of the job with all available information that relates to the determination of existing characteristics and conditions required by §1926.950(d). [§1926.952(a)(1)] (2) Briefing by the employee in charge. The employer shall ensure that the employee in charge conducts a job briefing that meets paragraphs (b), (c), and (d) of this section with the employees involved before they start each job. [§1926.952(a)(2)] (b) Subjects to be covered. The briefing shall cover at least the following subjects: Hazards associated with the job, work procedures involved, special precautions, energy-source controls, and personal protective equipment requirements. [§1926.952(b)] (c)  Number of briefings. [§1926.952(c)] (1) At least one before each day or shift. If the work or operations to be performed during the work day or shift are repetitive and similar, at least one job briefing shall be conducted before the start of the first job of each day or shift. [§1926.952(c)(1)] (2) Additional briefings. Additional job briefings shall be held if significant changes, which might affect the safety of the employees, occur during the course of the work. [§1926.952(c)(2)] (d) Extent of briefing. [§1926.952(d)] (1) Short discussion. A brief discussion is satisfactory if the work involved is routine and if the employees, by virtue of training and experience, can reasonably be expected to recognize and avoid the hazards involved in the job. [§1926.952(d)(1)] (2) Detailed discussion. A more extensive discussion shall be conducted: [§1926.952(d)(2)] (i) If the work is complicated or particularly hazardous, or [§1926.952(d)(2)(i)]

(ii) If the employee cannot be expected to recognize and avoid the hazards involved in the job. [§1926.952(d)(2)(ii)] Note to paragraph (d): The briefing must address all the subjects listed in paragraph (b) of this section.

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(e) Working alone. An employee working alone need not conduct a job briefing. However, the employer shall ensure that the tasks to be performed are planned as if a briefing were required. [§1926.952(e)]

§1926.953 Enclosed spaces (a) General. This section covers enclosed spaces that may be entered by employees. It does not apply to vented vaults if the employer makes a determination that the ventilation system is operating to protect employees before they enter the space. This section applies to routine entry into enclosed spaces. If, after the employer takes the precautions given in this section and in §1926.965, the hazards remaining in the enclosed space endanger the life of an entrant or could interfere with an entrant's escape from the space, then entry into the enclosed space must meet the permit space entry requirements of subpart AA of this part. For routine entries where the hazards remaining in the enclosed space do not endanger the life of an entrant or interfere with an entrant's escape from the space, this section applies in lieu of the permit-space entry requirements contained in §§1926.1204 through 926.1211. [§1926.953(a)] (b) Safe work practices. The employer shall ensure the use of safe work practices for entry into, and work in, enclosed spaces and for rescue of employees from such spaces. [§1926.953(b)] (c) Training. Each employee who enters an enclosed space or who serves as an attendant shall be trained in the hazards of enclosedspace entry, in enclosed-space entry procedures, and in enclosedspace rescue procedures. [§1926.953(c)] (d) Rescue equipment. Employers shall provide equipment to ensure the prompt and safe rescue of employees from the enclosed space. [§1926.953(d)] (e) Evaluating potential hazards. Before any entrance cover to an enclosed space is removed, the employer shall determine whether it is safe to do so by checking for the presence of any atmospheric pressure or temperature differences and by evaluating whether there might be a hazardous atmosphere in the space. Any conditions making it unsafe to remove the cover shall be eliminated before the cover is removed. [§1926.953(e)] Note to paragraph (e): The determination called for in this paragraph may consist of a check of the conditions that might foreseeably be in the enclosed space. For example, the cover could be checked to see if it is hot and, if it is fastened in place, could be loosened gradually to release any residual pressure. An evaluation also needs to be made of whether conditions at the site could cause a hazardous atmosphere, such as an oxygendeficient or flammable atmosphere, to develop within the space.

(f) Removing covers. When covers are removed from enclosed spaces, the opening shall be promptly guarded by a railing, temporary cover, or other barrier designed to prevent an accidental fall through the opening and to protect employees working in the space from objects entering the space. [§1926.953(f)] (g) Hazardous atmosphere. Employees may not enter any enclosed space while it contains a hazardous atmosphere, unless the entry conforms to the confined spaces in construction standard in subpart AA of this part. [§1926.953(g)] (h) Attendants. While work is being performed in the enclosed space, an attendant with first-aid training shall be immediately available outside the enclosed space to provide assistance if a hazard exists because of traffic patterns in the area of the opening used for entry. The attendant is not precluded from performing other duties outside the enclosed space if these duties do not distract the attendant from: Monitoring employees within the space or ensuring that it is safe for employees to enter and exit the space. [§1926.953(h)] Note to paragraph (h): See §1926.965 for additional requirements on attendants for work in manholes and vaults.

(i) Calibration of test instruments. Test instruments used to monitor atmospheres in enclosed spaces shall be kept in calibration and shall have a minimum accuracy of ±10 percent. [§1926.953(i)] (j) Testing for oxygen deficiency. Before an employee enters an enclosed space, the atmosphere in the enclosed space shall be tested for oxygen deficiency with a direct-reading meter or similar instrument, capable of collection and immediate analysis of data samples without the need for off-site evaluation. If continuous forced-air ventilation is provided, testing is not required provided that the procedures used ensure that employees are not exposed to the hazards posed by oxygen deficiency. [§1926.953(j)] (k) Testing for flammable gases and vapors. Before an employee enters an enclosed space, the internal atmosphere shall be tested for flammable gases and vapors with a direct-reading meter or similar instrument capable of collection and immediate analysis of data samples without the need for off-site evaluation. This test shall be performed after the oxygen testing and ventilation required by paragraph (j) of this section demonstrate that there is sufficient oxygen to ensure the accuracy of the test for flammability. [§1926.953(k)]

(l) Ventilation, and monitoring for flammable gases or vapors. If flammable gases or vapors are detected or if an oxygen deficiency is found, forced-air ventilation shall be used to maintain oxygen at a safe level and to prevent a hazardous concentration of flammable gases and vapors from accumulating. A continuous monitoring program to ensure that no increase in flammable gas

Personal protective equipment or vapor concentration above safe levels occurs may be followed in lieu of ventilation if flammable gases or vapors are initially detected at safe levels. [§1926.953(l)] Note to paragraph (l): See the definition of “hazardous atmosphere” for guidance in determining whether a specific concentration of a substance is hazardous.

(m) Specific ventilation requirements. If continuous forced-air ventilation is used, it shall begin before entry is made and shall be maintained long enough for the employer to be able to demonstrate that a safe atmosphere exists before employees are allowed to enter the work area. The forced-air ventilation shall be so directed as to ventilate the immediate area where employees are present within the enclosed space and shall continue until all employees leave the enclosed space. [§1926.953(m)] (n) Air supply. The air supply for the continuous forced-air ventilation shall be from a clean source and may not increase the hazards in the enclosed space. [§1926.953(n)] (o) Open flames. If open flames are used in enclosed spaces, a test for flammable gases and vapors shall be made immediately before the open flame device is used and at least once per hour while the device is used in the space. Testing shall be conducted more frequently if conditions present in the enclosed space indicate that once per hour is insufficient to detect hazardous accumulations of flammable gases or vapors. [§1926.953(o)] Note to paragraph (o): See the definition of “hazardous atmosphere” for guidance in determining whether a specific concentration of a substance is hazardous.

Note to §1926.953: Entries into enclosed spaces conducted in accordance with the permit space entry requirements of subpart AA of this part are considered as complying with this section.

[44 FR 8577, Feb. 9, 1979; 44 FR 20940, Apr. 6, 1979, as amended at 80 FR 25518, May 4, 2015]

§1926.954  Personal protective equipmentPer pso rn oa tl ectequii ve pm ent (a) General. Personal protective equipment shall meet the requirements of Subpart E of this part. [§1926.954(a)] Note to paragraph (a): Paragraph (d) of §1926.95 sets employer payment obligations for the personal protective equipment required by this subpart, including, but not limited to, the fall protection equipment required by paragraph (b) of this section, the electrical protective equipment required by §1926.960(c), and the flame-resistant and arc-rated clothing and other protective equipment required by §1926.960(g). (b) Fall protection. [§1926.954(b)]

(1) Personal fall arrest systems. [§1926.954(b)(1)] (i) Personal fall arrest systems shall meet the requirements of Subpart M of this part. [§1926.954(b)(1)(i)] (ii) Personal fall arrest equipment used by employees who are exposed to hazards from flames or electric arcs, as determined by the employer under §1926.960(g)(1), shall be capable of passing a drop test equivalent to that required by paragraph (b)(2)(xii) of this section after exposure to an electric arc with a heat energy of 40±5 cal/cm2. [§1926.954(b)(1)(ii)]

(2) Work-positioning equipment. Body belts and positioning straps for work-positioning equipment shall meet the following requirements: [§1926.954(b)(2)] (i) Hardware for body belts and positioning straps shall meet the following requirements: [§1926.954(b)(2)(i)] [A] Hardware shall be made of drop-forged steel, pressed steel, formed steel, or equivalent material. [§1926.954(b)(2)(i)[A]] [§1926.954(b)(2)(i)[B]]

[C] Hardware surfaces shall be smooth and free of sharp edges. [§1926.954(b)(2)(i)[C]] (ii) Buckles shall be capable of withstanding an 8.9-kilonewton (2,000-pound-force) tension test with a maximum permanent deformation no greater than 0.4 millimeters (0.0156 inches). [§1926.954(b)(2)(ii)] (iii) D rings shall be capable of withstanding a 22-kilonewton (5,000-pound-force) tensile test without cracking or breaking. [§1926.954(b)(2)(iii)] (iv) Snaphooks shall be capable of withstanding a 22-kilonewton (5,000-pound-force) tension test without failure. [§1926.954(b)(2)(iv)] Note to paragraph (b)(2)(iv): Distortion of the snaphook sufficient to release the keeper is considered to be tensile failure of a snaphook.

(v) Top grain leather or leather substitute may be used in the manufacture of body belts and positioning straps; however, leather and leather substitutes may not be used alone as a load-bearing component of the assembly. [§1926.954(b)(2)(v)] (vi) Plied fabric used in positioning straps and in load-bearing parts of body belts shall be constructed in such a way that no raw edges are exposed and the plies do not separate. [§1926.954(b)(2)(vi)]

(vii) Positioning straps shall be capable of withstanding the following tests: [§1926.954(b)(2)(vii)] [A] A dielectric test of 819.7 volts, AC, per centimeter (25,000 volts per foot) for 3 minutes without visible deterioration; [§1926.954(b)(2)(vii)[A]]

[B] A leakage test of 98.4 volts, AC, per centimeter (3,000 volts per foot) with a leakage current of no more than 1 mA; [§1926.954(b)(2)(vii)[B]] Note to paragraphs (b)(2)(vii)(A) and (b)(2)(vii)(B): Positioning straps that pass direct-current tests at equivalent voltages are considered as meeting this requirement.

[C] Tension tests of 20 kilonewtons (4,500 pounds-force) for sections free of buckle holes and of 15 kilonewtons (3,500 pounds-force) for sections with buckle holes; [§1926.954(b)(2)(vii)[C]]

[D] A buckle-tear test with a load of 4.4 kilonewtons (1,000 pounds-force); and [§1926.954(b)(2)(vii)[D]] [E] A flammability test in accordance with Table V-1. [§1926.954(b)(2)(vii)[E]]

Table V-1 — Flammability Test Test method

Criteria for passing the test

Vertically suspend a 500-mm (19.7-inch) length of strapping supporting a 100-kg (220.5-lb) weight

Any flames on the positioning strap shall self extinguish.

Use a butane or propane burner with a 76-mm (3-inch) flame

The positioning strap shall continue to support the 100-kg (220.5-lb) mass.

Direct the flame to an edge of the strapping at a distance of 25 mm (1 inch).

Remove the flame after 5 seconds.

Wait for any flames on the positioning strap to stop burning.

(viii) The cushion part of the body belt shall contain no exposed rivets on the inside and shall be at least 76 millimeters (3 inches) in width. [§1926.954(b)(2)(viii)] (ix) Tool loops shall be situated on the body of a body belt so that the 100 millimeters (4 inches) of the body belt that is in the center of the back, measuring from D ring to D ring, is free of tool loops and any other attachments. [§1926.954(b)(2)(ix)]

(x) Copper, steel, or equivalent liners shall be used around the bars of D rings to prevent wear between these members and the leather or fabric enclosing them. [§1926.954(b)(2)(x)] (xi) Snaphooks shall be of the locking type meeting the following requirements: [§1926.954(b)(2)(xi)] [A] The locking mechanism shall first be released, or a destructive force shall be placed on the keeper, before the keeper will open. [§1926.954(b)(2)(xi)[A]] [B] A force in the range of 6.7 N (1.5 lbf) to 17.8 N (4 lbf) shall be required to release the locking mechanism. [§1926.954(b)(2)(xi)[B]]

[C] With the locking mechanism released and with a force applied on the keeper against the face of the nose, the keeper may not begin to open with a force of 11.2 N (2.5 lbf) or less and shall begin to open with a maximum force of 17.8 N (4 lbf). [§1926.954(b)(2)(xi)[C]] (xii) Body belts and positioning straps shall be capable of withstanding a drop test as follows: [§1926.954(b)(2)(xii)] [A] The test mass shall be rigidly constructed of steel or equivalent material with a mass of 100 kg (220.5 lbm).

For work-positioning equipment used by employees weighing more than 140 kg (310 lbm) fully equipped, the test mass shall be increased proportionately (that is, the test mass must equal the mass of the equipped worker divided by 1.4). [§1926.954(b)(2)(xii)[A]] [B] For body belts, the body belt shall be fitted snugly around the test mass and shall be attached to the teststructure anchorage point by means of a wire rope. [§1926.954(b)(2)(xii)[B]]

[C] For positioning straps, the strap shall be adjusted to its shortest length possible to accommodate the test and connected to the test-structure anchorage point at one end and to the test mass on the other end. [§1926.954(b)(2)(xii)[C]]

[D] The test mass shall be dropped an unobstructed distance of 1 meter (39.4 inches) from a supporting structure that will sustain minimal deflection during the test. [§1926.954(b)(2)(xii)[D]]

[E] Body belts shall successfully arrest the fall of the test mass and shall be capable of supporting the mass after the test. [§1926.954(b)(2)(xii)[E]] [F] Positioning straps shall successfully arrest the fall of the test mass without breaking, and the arrest force may not exceed 17.8 kilonewtons (4,000 pounds-force).

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[B] Hardware shall have a corrosion-resistant finish.

§1926.954(b)

§1926.955

Subpart V – Power Transmission and Distribution Additionally, snaphooks on positioning straps may not distort to such an extent that the keeper would release. [§1926.954(b)(2)(xii)[F]] Note to paragraph (b)(2): When used by employees weighing no more than 140 kg (310 lbm) fully equipped, body belts and positioning straps that conform to American Society of Testing and Materials Standard Specifications for Personal Climbing Equipment, ASTM F887-12e1, are deemed to be in compliance with paragraph (b)(2) of this section.

(3) Care and use of personal fall protection equipment. [§1926.954(b)(3)]

(i) Work-positioning equipment shall be inspected before use each day to determine that the equipment is in safe working condition. Work-positioning equipment that is not in safe working condition may not be used. [§1926.954(b)(3)(i)] Note to paragraph (b)(3)(i): Appendix F to this subpart contains guidelines for inspecting work-positioning equipment.

(ii) Personal fall arrest systems shall be used in accordance with §1926.502(d). [§1926.954(b)(3)(ii)] Note to paragraph (b)(3)(ii): Fall protection equipment rigged to arrest falls is considered a fall arrest system and must meet the applicable requirements for the design and use of those systems. Fall protection equipment rigged for work positioning is considered work-positioning equipment and must meet the applicable requirements for the design and use of that equipment.

(iii) The employer shall ensure that employees use fall protection systems as follows: [§1926.954(b)(3)(iii)] [A] Each employee working from an aerial lift shall use a fall restraint system or a personal fall arrest system.

Paragraph (b)(2)(v) of §1926.453 does not apply. [§1926.954(b)(3)(iii)[A]]

[B] Except as provided in paragraph (b)(3)(iii)(C) of this section, each employee in elevated locations more than 1.2 meters (4 feet) above the ground on poles, towers, or similar structures shall use a personal fall arrest system, work-positioning equipment, or fall restraint system, as appropriate, if the employer has not provided other fall protection meeting Subpart M of this part. [§1926.954(b)(3)(iii)[B]]

[C] Until March 31, 2015, a qualified employee climbing or changing location on poles, towers, or similar structures need not use fall protection equipment, unless conditions, such as, but not limited to, ice, high winds, the design of the structure (for example, no provision for holding on with hands), or the presence of contaminants on the structure, could cause the employee to lose his or her grip or footing. On and after April 1, 2015, each qualified employee climbing or changing location on poles, towers, or similar structures must use fall protection equipment unless the employer can demonstrate that climbing or changing location with fall protection is infeasible or creates a greater hazard than climbing or changing location without it. [§1926.954(b)(3)(iii)[C]] Note 1 to paragraphs (b)(3)(iii)(B) and (b)(3)(iii)(C): These paragraphs apply to structures that support overhead electric power transmission and distribution lines and equipment. They do not apply to portions of buildings, such as loading docks, or to electric equipment, such as transformers and capacitors. Subpart M of this part contains the duty to provide fall protection associated with walking and working surfaces.

Note 2 to paragraphs (b)(3)(iii)(B) and (b)(3)(iii)(C): Until the employer ensures that employees are proficient in climbing and the use of fall protection under §1926.950(b)(7), the employees are not considered “qualified employees” for the purposes of paragraphs (b)(3)(iii)(B) and (b)(3)(iii)(C) of this section. These paragraphs require unqualified employees (including trainees) to use fall protection any time they are more than 1.2 meters (4 feet) above the ground.

(iv) On and after April 1, 2015, work-positioning systems shall be rigged so that an employee can free fall no more than 0.6 meters (2 feet). [§1926.954(b)(3)(iv)] (v) Anchorages for work-positioning equipment shall be capable of supporting at least twice the potential impact load of an employee's fall, or 13.3 kilonewtons (3,000 poundsforce), whichever is greater. [§1926.954(b)(3)(v)] Note to paragraph (b)(3)(v): Wood-pole fall-restriction devices meeting American Society of Testing and Materials Standard Specifications for Personal Climbing Equipment, ASTM F887-12e1, are deemed to meet the anchoragestrength requirement when they are used in accordance with manufacturers' instructions.

(vi) Unless the snaphook is a locking type and designed specifically for the following connections, snaphooks on work-positioning equipment may not be engaged: [§1926.954(b)(3)(vi)] [A] Directly to webbing, rope, or wire rope; [§1926.954(b)(3)(vi)[A]]

[B] To each other; [§1926.954(b)(3)(vi)[B]] [C] To a D ring to which another snaphook or other connector is attached; [§1926.954(b)(3)(vi)[C]] [D] To a horizontal lifeline; or [§1926.954(b)(3)(vi)[D]] [E] To any object that is incompatibly shaped or dimensioned in relation to the snaphook such that accidental disengagement could occur should the connected object sufficiently depress the snaphook keeper to allow release of the object. [§1926.954(b)(3)(vi)[E]]

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§1926.955  Portable ladders and platforms (a) General. Requirements for portable ladders contained in Subpart X of this part apply in addition to the requirements of this section, except as specifically noted in paragraph (b) of this section. [§1926.955(a)]

(b) Special ladders and platforms. Portable ladders used on structures or conductors in conjunction with overhead line work need not meet §1926.1053(b)(5)(i) and (b)(12). Portable ladders and platforms used on structures or conductors in conjunction with overhead line work shall meet the following requirements: [§1926.955(b)]

(1) Design load. In the configurations in which they are used, portable platforms shall be capable of supporting without failure at least 2.5 times the maximum intended load. [§1926.955(b)(1)] (2) Maximum load. Portable ladders and platforms may not be loaded in excess of the working loads for which they are designed. [§1926.955(b)(2)] (3) Securing in place. Portable ladders and platforms shall be secured to prevent them from becoming dislodged. [§1926.955(b)(3)]

(4) Intended use. Portable ladders and platforms may be used only in applications for which they are designed. [§1926.955(b)(4)] (c) Conductive ladders. Portable metal ladders and other portable conductive ladders may not be used near exposed energized lines or equipment. However, in specialized high-voltage work, conductive ladders shall be used when the employer demonstrates that nonconductive ladders would present a greater hazard to employees than conductive ladders. [§1926.955(c)]

§1926.956  Hand and portable power equipment (a) General. Paragraph (b) of this section applies to electric equipment connected by cord and plug. Paragraph (c) of this section applies to portable and vehicle-mounted generators used to supply cord- and plug-connected equipment. Paragraph (d) of this section applies to hydraulic and pneumatic tools. [§1926.956(a)] (b) Cord- and plug-connected equipment. Cord- and plug-connected equipment not covered by Subpart K of this part shall comply with one of the following instead of §1926.302(a)(1): [§1926.956(b)]

(1)  The equipment shall be equipped with a cord containing an equipment grounding conductor connected to the equipment frame and to a means for grounding the other end of the conductor (however, this option may not be used where the introduction of the ground into the work environment increases the hazard to an employee); or [§1926.956(b)(1)] (2) The equipment shall be of the double-insulated type conforming to Subpart K of this part; or [§1926.956(b)(2)] (3) The equipment shall be connected to the power supply through an isolating transformer with an ungrounded secondary of not more than 50 volts. [§1926.956(b)(3)] (c) Portable and vehicle-mounted generators. Portable and vehicle-mounted generators used to supply cord- and plug-connected equipment covered by paragraph (b) of this section shall meet the following requirements: [§1926.956(c)] (1) Equipment to be supplied. The generator may only supply equipment located on the generator or the vehicle and cordand plug-connected equipment through receptacles mounted on the generator or the vehicle. [§1926.956(c)(1)] (2) Equipment grounding. The non-current-carrying metal parts of equipment and the equipment grounding conductor terminals of the receptacles shall be bonded to the generator frame. [§1926.956(c)(2)]

(3) Bonding the frame. For vehicle-mounted generators, the frame of the generator shall be bonded to the vehicle frame. [§1926.956(c)(3)]

(4) Bonding the neutral conductor. Any neutral conductor shall be bonded to the generator frame. [§1926.956(c)(4)] (d) Hydraulic and pneumatic tools. [§1926.956(d)] (1) Hydraulic fluid in insulating tools. Paragraph (d)(1) of §1926.302 does not apply to hydraulic fluid used in insulating sections of hydraulic tools. [§1926.956(d)(1)] (2) Operating pressure. Safe operating pressures for hydraulic and pneumatic tools, hoses, valves, pipes, filters, and fittings may not be exceeded. [§1926.956(d)(2)] Note to paragraph (d)(2): If any hazardous defects are present, no operating pressure is safe, and the hydraulic or pneumatic equipment involved may not be used.

In the absence of defects, the maximum rated operating pressure is the maximum safe pressure.

(3) Work near energized parts. A hydraulic or pneumatic tool used where it may contact exposed energized parts shall be designed and maintained for such use. [§1926.956(d)(3)] (4) Protection against vacuum formation. The hydraulic system supplying a hydraulic tool used where it may contact exposed live parts shall provide protection against loss of insulating

Working on or near exposed energized parts (2) Requirements for working without electrical protective equipment. When an employee performs work near exposed parts energized at more than 600 volts, but not more than 72.5 kilovolts, and is not wearing rubber insulating gloves, being protected by insulating equipment covering the energized parts, performing work using live-line tools, or performing live-line barehand work under §1926.964(c), the employee shall work from a position where he or she cannot reach into the minimum approach distance, established by the employer under paragraph (c)(1) of this section. [§1926.960(d)(2)]

(e) Making connections. The employer shall ensure that employees make connections as follows: [§1926.960(e)] (1) Connecting. In connecting deenergized equipment or lines to an energized circuit by means of a conducting wire or device, an employee shall first attach the wire to the deenergized part; [§1926.960(e)(1)]

(2) Disconnecting. When disconnecting equipment or lines from an energized circuit by means of a conducting wire or device, an employee shall remove the source end first; and [§1926.960(e)(2)]

(3) Loose conductors. When lines or equipment are connected to or disconnected from energized circuits, an employee shall keep loose conductors away from exposed energized parts. [§1926.960(e)(3)]

(f) Conductive articles. When an employee performs work within reaching distance of exposed energized parts of equipment, the employer shall ensure that the employee removes or renders nonconductive all exposed conductive articles, such as keychains or watch chains, rings, or wrist watches or bands, unless such articles do not increase the hazards associated with contact with the energized parts. [§1926.960(f)] (g) Protection from flames and electric arcs. [§1926.960(g)] (1) Hazard assessment. The employer shall assess the workplace to identify employees exposed to hazards from flames or from electric arcs. [§1926.960(g)(1)] (2)  Estimate of available heat energy. For each employee exposed to hazards from electric arcs, the employer shall make a reasonable estimate of the incident heat energy to which the employee would be exposed. [§1926.960(g)(2)]

(3) Prohibited clothing. The employer shall ensure that each employee who is exposed to hazards from flames or electric arcs does not wear clothing that could melt onto his or her skin or that could ignite and continue to burn when exposed to flames or the heat energy estimated under paragraph (g)(2) of this section. [§1926.960(g)(3)] Note to paragraph (g)(3): This paragraph prohibits clothing made from acetate, nylon, polyester, rayon and polypropylene, either alone or in blends, unless the employer demonstrates that the fabric has been treated to withstand the conditions that may be encountered by the employee or that the employee wears the clothing in such a manner as to eliminate the hazard involved.

(4) Flame-resistant clothing. The employer shall ensure that the outer layer of clothing worn by an employee, except for clothing not required to be arc rated under paragraphs (g)(5)(i) through (g)(5)(v) of this section, is flame resistant under any of the following conditions: [§1926.960(g)(4)] (i) The employee is exposed to contact with energized circuit parts operating at more than 600 volts, [§1926.960(g)(4)(i)] (ii) An electric arc could ignite flammable material in the work area that, in turn, could ignite the employee's clothing, [§1926.960(g)(4)(ii)]

(iii) Molten metal or electric arcs from faulted conductors in the work area could ignite the employee's clothing, or [§1926.960(g)(4)(iii)] Note to paragraph (g)(4)(iii): This paragraph does not apply to conductors that are capable of carrying, without failure, the maximum available fault current for the time the circuit protective devices take to interrupt the fault.

(iv) The incident heat energy estimated under paragraph (g)(2) of this section exceeds 2.0 cal/cm2. [§1926.960(g)(4)(iv)]

(5)  Arc rating. The employer shall ensure that each employee exposed to hazards from electric arcs wears protective clothing and other protective equipment with an arc rating greater than or equal to the heat energy estimated under paragraph (g)(2) of this section whenever that estimate exceeds 2.0 cal/cm2. This protective equipment shall cover the employee's entire body, except as follows: [§1926.960(g)(5)]

(i) Arc-rated protection is not necessary for the employee's hands when the employee is wearing rubber insulating gloves with protectors or, if the estimated incident energy is no more than 14 cal/cm2, heavy-duty leather work gloves with a weight of at least 407 gm/m2 (12 oz/yd2), [§1926.960(g)(5)(i)]

(ii) Arc-rated protection is not necessary for the employee's feet when the employee is wearing heavy-duty work shoes or boots, [§1926.960(g)(5)(ii)] (iii) Arc-rated protection is not necessary for the employee's head when the employee is wearing head protection meeting §1926.100(b)(2) if the estimated incident energy is less than 9 cal/cm2 for exposures involving singlephase arcs in open air or 5 cal/cm2 for other exposures, [§1926.960(g)(5)(iii)]

(iv) The protection for the employee's head may consist of head protection meeting §1926.100(b)(2) and a faceshield with a minimum arc rating of 8 cal/cm2 if the estimated incident-energy exposure is less than 13 cal/cm2 for exposures involving single-phase arcs in open air or 9 cal/cm2 for other exposures, and [§1926.960(g)(5)(iv)] (v) For exposures involving single-phase arcs in open air, the arc rating for the employee's head and face protection may be 4 cal/cm2 less than the estimated incident energy. [§1926.960(g)(5)(v)] Note to paragraph (g): See Appendix E to this subpart for further information on the selection of appropriate protection.

(6) Dates. [§1926.960(g)(6)]

(i) The obligation in paragraph (g)(2) of this section for the employer to make reasonable estimates of incident energy commences January 1, 2015. [§1926.960(g)(6)(i)] (ii) The obligation in paragraph (g)(4)(iv) of this section for the employer to ensure that the outer layer of clothing worn by an employee is flame-resistant when the estimated incident heat energy exceeds 2.0 cal/cm2 commences April 1, 2015. [§1926.960(g)(6)(ii)] (iii) The obligation in paragraph (g)(5) of this section for the employer to ensure that each employee exposed to hazards from electric arcs wears the required arc-rated protective equipment commences April 1, 2015. [§1926.960(g)(6)(iii)]

(h) Fuse handling. When an employee must install or remove fuses with one or both terminals energized at more than 300 volts, or with exposed parts energized at more than 50 volts, the employer shall ensure that the employee uses tools or gloves rated for the voltage. When an employee installs or removes expulsion-type fuses with one or both terminals energized at more than 300 volts, the employer shall ensure that the employee wears eye protection meeting the requirements of Subpart E of this part, uses a tool rated for the voltage, and is clear of the exhaust path of the fuse barrel. [§1926.960(h)] (i) Covered (noninsulated) conductors. The requirements of this section that pertain to the hazards of exposed live parts also apply when an employee performs work in proximity to covered (noninsulated) wires. [§1926.960(i)] (j) Non-current-carrying metal parts. Non-current-carrying metal parts of equipment or devices, such as transformer cases and circuit-breaker housings, shall be treated as energized at the highest voltage to which these parts are exposed, unless the employer inspects the installation and determines that these parts are grounded before employees begin performing the work. [§1926.960(j)]

(k) Opening and closing circuits under load. [§1926.960(k)] (1) The employer shall ensure that devices used by employees to open circuits under load conditions are designed to interrupt the current involved. [§1926.960(k)(1)] (2) The employer shall ensure that devices used by employees to close circuits under load conditions are designed to safely carry the current involved. [§1926.960(k)(2)]

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Note 1 to paragraph (g)(2): Appendix E to this subpart provides guidance on estimating available heat energy. The Occupational Safety and Health Administration will deem employers following the guidance in Appendix E to this subpart to be in compliance with paragraph (g)(2) of this section. An employer may choose a method of calculating incident heat energy not included in Appendix E to this subpart if the chosen method reasonably predicts the incident energy to which the employee would be exposed.

Note 2 to paragraph (g)(2): This paragraph does not require the employer to estimate the incident heat energy exposure for every job task performed by each employee. The employer may make broad estimates that cover multiple system areas provided the employer uses reasonable assumptions about the energyexposure distribution throughout the system and provided the estimates represent the maximum employee exposure for those areas. For example, the employer could estimate the heat energy just outside a substation feeding a radial distribution system and use that estimate for all jobs performed on that radial system.

§1926.960(k)

§1926.960

Subpart V – Power Transmission and Distribution

Table V-2 — AC Live-Line Work Minimum Approach Distance The minimum approach distance (MAD; in meters) shall conform to the following equations.

For Phase-to-phase system voltages of 50 V to 300 V: 1 MAD = avoid contact

For phase-to-phase system voltages of 301 V to 5 kV: 1 MAD = M + D, where D = 0.02 m

the electrical component of the minimum approach distance

M = 0.31 m for voltages up to 750 V and 0.61 m otherwise

the inadvertent movement factor

For phase-to-phase system voltages of 5.1 kV to 72.5 kV: 1 4 MAD = M + AD, where M = 0.61 m

the inadvertent movement factor

A = the applicable value from Table V-4

the altitude correction factor

D = the value from Table V-3 corresponding to the voltage and exposure or the value of the electrical component of the minimum approach distance calculated using the method provided in Appendix B to the electrical component of the minimum approach distance this Subpart.

For phase-to-phase system voltages of more than 72.5 kV, nominal: 2 4 MAD = 0.3048(C + a)VL-GTA + M, where C = 0.01 for phase-to-ground exposures that the employer can demonstrate consist only of air across the approach distance (gap), 0.01 for phase-to-phase exposures if the employer can demonstrate that no insulated tool spans the gap and that no large conductive object is in the gap, or 0.011 otherwise.

VL-G = phase -to-ground rms voltage, in kV T = maximum anticipated per-unit transient overvoltage; for phase-to-ground exposures, T equals TL-G,the maximum per unit transient overvoltage phase-to-ground, determined by the employer under paragraph (c)(1)(ii) of this section; for phase-to-phase exposures, T equals 135 TL-G + 0.45 A = altitude correction factor from Table V-4 M = 0.31 m, the inadvertent movement factor a = saturation factor, as follows:

Phase-to-Ground Exposures VPeak = TL-G VL-G2 a

635 kV or less

635.1 to 915 kV

915.1 to 1,050 kV

More than 1,050 kV

0

(VPeak-635)/140,000

(VPeak-645)/135,000

(VPeak-675)/125,000

Phase-to-Phase Exposures 3 VPeak = (1.35TL-G +0.45)VL-G 2 a 1

630 kV or less

630.1 to 848 kV

848.1 to 1,131 kV

1,131.1 to 1,485 kV

More than 1,485 kV

0

(VPeak-630)/155,000

(VPeak-633.6)/152,207

(VPeak-628)/153,846

(VPeak-350.5)/203,666

Employers may use the minimum approach distances in Table V-5. If the worksite is at an elevation of more than 900 meters (3,000 feet), see footnote 1 to Table V-5.

2Employers may use the minimum approach distances in Table V-6, except that the employer may not use the minimum approach distances in Table V-6 for phase-to-phase exposures if an

insulated tool spans the gap or if any large conductive object is in the gap. If the worksite is at an elevation of more than 900 meters (3,000 feet), see footnote 1 to Table V-6. Employers may use the minimum approach distances in Table 7 through Table 14 in Appendix B to this Subpart, which calculated MAD for various values of T, provided the employer follows the notes to those tables.

3Use the equations for phase-to-ground exposures (with V

ductive object is in the gap.

Peak for phase-to-phase exposures) unless the employer can demonstrate that no insulated too spans the gap and that no large con-

4Until March 31, 2015, employers may use the minimum approach distances in Table 6 in Appendix B to this Subpart.

Table V-4 — Altitude Correction Factor

.

Table V-3 — Electrical Component of the Minimum Approach Distance (D; in Meters) at 5.1 to 72.5 kV Phase-to-ground exposure

Phase-to-phase exposure

D (m)

5.1 to 15.0 15.1 to 36.0

Nominal voltage (kV) phase-to-phase

(continued)

Altitude above sea level (m)

A

4,201 to 4,800

1.35

4,801 to 5,400

1.39

D (m)

5,401 to 6,000

1.44

0.04

0.07

0.16

0.28

Table V-5 — Alternative Minimum Approach Distances for Voltages of 72.5 kV and Less1

36.1 to 46.0

0.23

0.37

46.1 to 72.5

0.39

0.59

Table V-4 — Altitude Correction Factor Altitude above sea level (m) 0 to 900 901 to 1,200

Distance Nominal voltage (kV) phase-tophase

m

A 1.00

Phase-to-ground exposure

2

0.050 0.300

Phase-to-phase exposure

ft

m

Avoid contact

ft Avoid contact

1.02

0.301 to 0.7502

0.33

1.09

0.33

1.09

0.63

2.07

0.63

2.07

1,201 to 1,500

1.05

0.751 to 5.0

1,501 to 1,800

1.08

5.1 to 15.0

0.65

2.14

0.68

2.24

1,801 to 2,100

1.11

15.1 to 36.0

0.77

2.53

0.89

2.92

2,101 to 2,400

1.14

36.1 to 46.0

0.84

2.76

0.98

3.22

2,401 to 2,700

1.17

46.1 to 72.5

1.00

3.29

1.20

3.94

2,701 to 3,000

1.20

3,001 to 3,600

1.25

3,601 to 4,200

1.30

132

1Employers may use the minimum approach distances in this table provided the worksite is

at an elevation of 900 meters (3,000 feet) or less. If employees will be working at elevations greater than 900 meters (3,000 feet) above mean sea level, the employer shall determine minimum approach distances by multiplying the distances in this table by the correction factor in Table V-4 corresponding to the altitude of the work.

2For single-phase systems, use voltage-to-ground.

Deenergizing lines and equipment for employee protection Table V-6 — Alternative Minimum Approach Distances for Voltages of More Than 72.5 kV 1 2 3 Voltage range phase to phase (kV)

Phase-to-ground exposure m

ft

m

ft

72.6 to 121.0

1.13

3.71

1.42

4.66

Phase-to-phase exposure

121.1 to 145.0

1.30

4.27

1.64

5.38

145.1 to 169.0

1.46

4.79

1.94

6.36 10.10

169.1 to 242.0

2.01

6.59

3.08

242.1 to 362.0

3.41

11.19

5.52

18.11

362.1 to 420.0

4.25

13.94

6.81

22.34

420.1 to 550.0

5.07

16.63

8.24

27.03

550.1 to 800.0

6.88

22.57

11.38

37.34

1Employers may use the minimum approach distances in this table provided the worksite is

at an elevation of 900 meters (3,000 feet) or less. If employees will be working at elevations greater than 900 meters (3,000 feet) above mean sea level, the employer shall determine minimum approach distances by multiplying the distances in this table by the correction factor in Table V-4 corresponding to the altitude of the work.

2Employers may use the phase-to-phase minimum approach distances in this table provided

that no insulated tool spans the gap and no large conductive object is in the gap.

3The clear live-line tool distance shall equal or exceed the values for the indicated voltage

ranges.

Table V-7 — DC Live-Line Minimum Approach Distance (in Meters) With Overvoltage Factor 1 distance (m) maximum line-to-ground voltage (kV)

Maximum anticipated per-unit transient overvoltage

250

400

500

600

750

1.5 or less

1.12

1.60

2.06

2.62

3.61

1.6

1.17

1.69

2.24

2.86

3.98

1.7

1.23

1.82

2.42

3.12

4.37

1.8

1.28

1.95

2.62

3.39

4.79

1The distances specified in this table are for air, bare-hand, and live-line tool conditions. If

employees will be working at elevations greater than 900 meters (3,000 feet) above mean sea level, the employer shall determine minimum approach distances by multiplying the distances in this table by the correction factor in Table V-4 corresponding to the altitude of the work.

Table V-8 — Assumed Maximum Per-Unit Transient Overvoltage Type of current (ac or dc)

Assumed maximum per-unit transient overvoltage

72.6 to 420.0

ac

3.5

420.1 to 550.0

ac

3.0

550.1 to 800.0

ac

2.5

250 to 750

dc

1.8

Voltage range (kV)

§1926.961 Deenergizing lines and equipment for employee protection (a) Application. This section applies to the deenergizing of transmission and distribution lines and equipment for the purpose of protecting employees. Conductors and parts of electric equipment that have been deenergized under procedures other than those required by this section shall be treated as energized. [§1926.961(a)] (b) General. [§1926.961(b)] (1) System operator. If a system operator is in charge of the lines or equipment and their means of disconnection, the employer shall designate one employee in the crew to be in charge of the clearance and shall comply with all of the requirements of paragraph (c) of this section in the order specified. [§1926.961(b)(1)]

(2) No system operator. If no system operator is in charge of the lines or equipment and their means of disconnection, the employer shall designate one employee in the crew to be in charge of the clearance and to perform the functions that the system operator would otherwise perform under this section.

All of the requirements of paragraph (c) of this section apply, in the order specified, except as provided in paragraph (b)(3) of this section. [§1926.961(b)(2)] (3) Single crews working with the means of disconnection under the control of the employee in charge of the clearance. If only one crew will be working on the lines or equipment and if the means of disconnection is accessible and visible to, and under the sole control of, the employee in charge of the clearance, paragraphs (c)(1), (c)(3), and (c)(5) of this section do not apply.

Additionally, the employer does not need to use the tags required by the remaining provisions of paragraph (c) of this section. [§1926.961(b)(3)] (4) Multiple crews. If two or more crews will be working on the same lines or equipment, then: [§1926.961(b)(4)] (i) The crews shall coordinate their activities under this section with a single employee in charge of the clearance for all of the crews and follow the requirements of this section as if all of the employees formed a single crew, or [§1926.961(b)(4)(i)] (ii) Each crew shall independently comply with this section and, if there is no system operator in charge of the lines or equipment, shall have separate tags and coordinate deenergizing and reenergizing the lines and equipment with the other crews. [§1926.961(b)(4)(ii)] (5) Disconnecting means accessible to general public. The employer shall render any disconnecting means that are accessible to individuals outside the employer's control (for example, the general public) inoperable while the disconnecting means are open for the purpose of protecting employees. [§1926.961(b)(5)] (c) Deenergizing lines and equipment. [§1926.961(c)] (1) Request to deenergize. The employee that the employer designates pursuant to paragraph (b) of this section as being in charge of the clearance shall make a request of the system operator to deenergize the particular section of line or equipment. The designated employee becomes the employee in charge (as this term is used in paragraph (c) of this section) and is responsible for the clearance. [§1926.961(c)(1)] (2) Open disconnecting means. The employer shall ensure that all switches, disconnectors, jumpers, taps, and other means through which known sources of electric energy may be supplied to the particular lines and equipment to be deenergized are open. The employer shall render such means inoperable, unless its design does not so permit, and then ensure that such means are tagged to indicate that employees are at work. [§1926.961(c)(2)]

(3) Automatically and remotely controlled switches. The employer shall ensure that automatically and remotely controlled switches that could cause the opened disconnecting means to close are also tagged at the points of control. The employer shall render the automatic or remote control feature inoperable, unless its design does not so permit. [§1926.961(c)(3)] (4) Network protectors. The employer need not use the tags mentioned in paragraphs (c)(2) and (c)(3) of this section on a network protector for work on the primary feeder for the network protector's associated network transformer when the employer can demonstrate all of the following conditions: [§1926.961(c)(4)] (i) Every network protector is maintained so that it will immediately trip open if closed when a primary conductor is deenergized; [§1926.961(c)(4)(i)] (ii) Employees cannot manually place any network protector in a closed position without the use of tools, and any manual override position is blocked, locked, or otherwise disabled; and [§1926.961(c)(4)(ii)] (iii) The employer has procedures for manually overriding any network protector that incorporate provisions for determining, before anyone places a network protector in a closed position, that: The line connected to the network protector is not deenergized for the protection of any employee working on the line; and (if the line connected to the network protector is not deenergized for the protection of any employee working on the line) the primary conductors for the network protector are energized. [§1926.961(c)(4)(iii)] (5) Tags. Tags shall prohibit operation of the disconnecting means and shall indicate that employees are at work. [§1926.961(c)(5)] (6) Test for energized condition. After the applicable requirements in paragraphs (c)(1) through (c)(5) of this section have been followed and the system operator gives a clearance to the employee in charge, the employer shall ensure that the lines and equipment are deenergized by testing the lines and equipment to be worked with a device designed to detect voltage. [§1926.961(c)(6)]

(7) Install grounds. The employer shall ensure the installation of protective grounds as required by §1926.962. [§1926.961(c)(7)] (8) Consider lines and equipment deenergized. After the applicable requirements of paragraphs (c)(1) through (c)(7) of this section have been followed, the lines and equipment involved may be considered deenergized. [§1926.961(c)(8)] (9) Transferring clearances. To transfer the clearance, the employee in charge (or the employee's supervisor if the employee in charge must leave the worksite due to illness or other emergency) shall inform the system operator and employees in the crew; and the new employee in charge shall be responsible for the clearance. [§1926.961(c)(9)]

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V Power Transmission and Distribution

[79 FR 20696, Apr. 11, 2014, as amended at 79 FR 56962, Sept. 24, 2014; 80 FR 60040, Oct. 5, 2015]

§1926.961(c)