Solution and Answer Guide Illustrated Guide to the National Electrical Code 9th Edition by Charles R

Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 1: Introduction to the National Electrical Code®

Solution and Answer Guide

MILLER/S ANDEFUR, ILLUSTRATED GUIDE TO THE NEC®, 21E, ©2024, 9780357766712; UNIT 1: INTRODUCTION TO THE NATIONAL E LECTRICAL CODE®

TABLE OF CONTENTS Unit 1 Competency Test ............................................................................................................................. 1

UNIT 1 COMPETENCY TEST 1. The National Fire Protection Association has acted as sponsor of the National Electrical Code since__________________. a. NEC® Reference: Page 1 b. Answer: 1911 2. Informative Annex _______________ provides a list of product safety standards used for product listing where that listing is required by the NEC. a. NEC® Reference: Informative Annex A b. Answer: A 3. Which chapters in the NEC apply generally to all installations? a. NEC® Reference: 90.3 b. Answer: Chapters 1, 2, 3, and 4 4. Every three years, the National Electrical Code is revised, but the Code has only been on a three-year revision cycle since _______________. a. NEC® Reference: Page 1 b. Answer: 1975 5. The purpose of the National Electrical Code is the practical safeguarding of ___________ from hazards arising from the use of electricity. a. NEC® Reference: persons and property b. Answer: 90.2(A) 6. The original Code document was developed _______________ in as a result of the united efforts of various insurance, electrical, architectural, and allied interests. a. NEC® Reference: Page 1 b. Answer: 1897

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 1: Introduction to the National Electrical Code®

7. Informative annexes are not part of the requirements of the NEC but are included for _______________ only. a. NEC® Reference: 90.3 b. Answer: informational purposes 8. What city was home to the first central-station electric generating plant developed by Thomas A. Edison? a. NEC® Reference: Page 2 b. Answer: New York City 9. Chapter _______________ consists of tables that are applicable as referenced. a. NEC® Reference: 90.3 b. Answer: 9 10. In the NEC, UL is the abbreviation for _______________. a. NEC® Reference: Annex I, footnote under Table I.3 b. Answer: Underwriters Laboratories 11. Equipment that is listed, labeled, or both, or identified for a use shall be installed and used in accordance with any _______________ included in the listing, labeling, or identification. a. NEC® Reference: 110.3(B) b. Answer: instructions

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 2: Definitions®

Solution and Answer Guide

MILLER/S ANDEFUR, ILLUSTRATED GUIDE TO THE NEC®, 21E, ©2024, 9780357766712; UNIT 2: DEFINITIONS®

TABLE OF CONTENTS Unit 2 Competency Test ............................................................................................................................. 1

UNIT 2 COMPETENCY TEST 1. A(n) __________________ branch circuit supplies two or more receptacles or outlets for lighting and appliances. a. NEC® Reference: Article 100 (Branch-Circuit, General Purpose) b. Answer: general purpose 2. __________________ is the largest amount of current capable of being delivered at a point on the electrical system during a short-circuit condition. a. NEC® Reference: Article 100 (Fault Current, Available) b. Answer: Available fault current 3. A(n) __________________ branch circuit consists of two or more ungrounded conductors having a potential difference between them, and a grounded conductor having equal potential difference between it and each ungrounded conductor of the circuit and that is connected to the neutral or grounded conductor of the system. a. NEC® Reference: multiwire b. Answer: Article 100 (Branch-Circuit, Multiwire) 4. An intermittent operation in which load conditions are regularly recurrent is the definition of __________________. a. NEC® Reference: Article 100 (Duty, Periodic) b. Answer: periodic duty 5. The __________________ is the connection between the grounded-circuit conductor and the equipment grounding conductor at the service. a. NEC® Reference: Article 100 (Bonding Jumper, Main) b. Answer: main bonding jumper

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 2: Definitions®

6. A(n) __________________ is used to connect the system grounded conductor or the equipment to a grounding electrode or to a point on the grounding electrode system. a. NEC® Reference: Article 100 (Grounding Electrode Conductor) b. Answer: grounding electrode conductor 7. Rainproof, raintight, or watertight equipment can fulfill the requirements for __________________ where varying weather conditions other than wetness, such as snow, ice, dust, or temperature extremes, are not a factor. a. NEC® Reference: Article 100 (Weatherproof: Informational Note) b. Answer: weatherproof 8. A(n) __________________ is an intentionally constructed, low-impedance electrically conductive path designed and intended to carry current during ground-fault events from the point of a ground fault on a wiring system to the electrical supply source and that facilitates the operation of the overcurrent protective device or ground-fault detectors. a. NEC® Reference: Article 100 (Ground Fault Current Path, Effective) b. Answer: effective ground-fault current path 9. A(n) __________________ is a manual, nonautomatic, or automatic operated device used in conjunction with a transfer switch to provide a means of directly connecting load conductors to a power source and of disconnecting the transfer switch. a. NEC® Reference: Article 100 (Transfer Switch, Bypass Isolation) b. Answer: bypass isolation transfer switch 10. A surface, flush, or freestanding assemblage with a raceway, fittings, or other enclosure provided with one or more receptacles, for the purpose of supplying power to utilization equipment is called a(n). a. NEC® Reference: Article 100 (Multioutlet Assembly) b. Answer: multioutlet assembly 11. A raceway encased in 4 in. (102 mm) of concrete on the ground floor (in direct contact with the earth) shall be considered a(n) __________________ location. a. NEC® Reference: Article 100 (Location, Wet) b. Answer: wet 12. A(n) __________________ may consist of one or more sensing elements integral with the motor-compressor and an external control device. a. NEC® Reference: Article 100 (Thermal Protector: Informational Note) b. Answer: thermal protector

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 2: Definitions®

13. An enclosure designed for either surface or flush mounting and provided with a frame, mat, or trim in which a swinging door or doors are or can be hung is called a(n) __________________. a. NEC® Reference: Article 100 (Cabinet) b. Answer: cabinet 14. A(n) __________________ is a shaftway, hatchway, well hole, or other vertical opening of space in which an elevator or dumbwaiter is designed to operate. a. NEC® Reference: Article 100 (Hoistway) b. Answer: hoistway 15. A multiwire branch circuit can supply: I. 20/240 volts to only one piece of utilization equipment II. 120/240 volts where all ungrounded conductors are opened simultaneously a) I only b) II only c) both I and II d) neither I nor II a. NEC® Reference: 210.4(C) Exceptions No. 1 and 2 b. Answer: c) both I and II 16. An overcurrent protective device with a circuit opening fusible part that is heated and severed by the passage of overcurrent through it is the definition of a(n) __________________. a. NEC® Reference: Article 100 (Fuse) b. Answer: fuse 17. __________________ is a string of outdoor lights suspended between two points. a. NEC® Reference: Article 100 (Festoon Lighting) b. Answer: Festoon lighting 18. Name two items that must be present when defining an area as a bathroom. a. NEC® Reference: Article 100 (Bathroom) b. Answer: One item named must be a sink; the other item can be a toilet, a urinal, a tub, a shower, a bidet, or similar plumbing fixture.

19. A continuous load is where the __________________ current is expected to continue for three hours or more. a) 80% b) average c) maximum d) 125% a. NEC® Reference: Article 100 (Continuous Load) b. Answer: c) maximum 20. Solidly grounded is defined as connected to ground without inserting any __________________ or impedance device. a. NEC® Reference: Article 100 (Grounded, Solidly) b. Answer: resistor © 2024 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 2: Definitions®

21. A(n) __________________ is a point on the wiring system at which current is taken to supply utilization equipment. a. NEC® Reference: Article 100 (Outlet) b. Answer: outlet 22. A(n) __________________ is defined as the circuit conductors between the final overcurrent device protecting the circuit and the outlet(s). a. NEC® Reference: Article 100 (Branch-Circuit) b. Answer: branch-circuit 23. __________________ enclosures are constructed or protected so that exposure to a beating rain will not result in the entrance of water under specified test conditions. a. NEC® Reference: Article 100 (Raintight) b. Answer: Raintight 24. Continuous duty is an operation at a substantially constant load for __________________. a) 1 hour or more b) 1½ hours or more c) 3 hours or more d) an indefinitely long time a. NEC® Reference: Article 100 (Duty, Continuous) b. Answer: d) an indefinitely long time 25. Ampacity is defined as the maximum current, in amperes, that a conductor can carry continuously under the conditions of use without exceeding __________________. a. NEC® Reference: Article 100 (Ampacity) b. Answer: its temperature rating 26. When a disconnecting means must be located within sight from a motor, the disconnect must be visible and not more than __________________ ft from the motor. a. NEC® Reference: Article 100 (In Sight From [Within Sight From, Within Sight]) b. Answer: 50 27. A building containing three dwelling units is called a(n) __________________. a. NEC® Reference: Article 100 (Dwelling, Multifamily) b. Answer: multifamily dwelling 28. Ground is defined as __________________. a. NEC® Reference: Article 100 (Ground) b. Answer: the earth

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 2: Definitions®

29. At the neutral point of the system, the __________________ of the nominal voltages from all other phases within the system that utilize the neutral, with respect to the neutral point, is zero potential. a. NEC® Reference: Article 100 (Neutral Point: Informational Note) b. Answer: vectorial sum 30. Four panelboards are in an electrical room behind locked doors. Only authorized personnel have keys to this electrical room. In accordance with 240.24, overcurrent devices shall be readily accessible. Since a key must be used to gain entry into the electrical room, are the overcurrent devices in these panelboards considered readily accessible? a. NEC® Reference: Article 100 (Accessible, Readily) b. Answer: yes 31. A(n) __________________ is defined as an electrical power supply output, other than a service, having no direct connection(s) to circuit conductors of any other electrical source other than those established by grounding and bonding connections. a. NEC® Reference: Article 100 (Separately Derived System) b. Answer: separately derived system 32. A feeder is defined as all circuit conductors between the service equipment, the source of a separately derived system, or other power supply source and the final __________________ overcurrent device. a. NEC® Reference: Article 100 (Feeder) b. Answer: branch-circuit 33. A(n) __________________ is defined as utilization equipment, generally other than industrial, that is fastened in place, stationary, or portable; is normally built in a standardized size or type; and is installed or connected as a unit to perform one or more functions such as clothes washing, air-conditioning, food mixing, deep frying, and so forth. a. NEC® Reference: Article 100 (Appliance) b. Answer: appliance 34. A motor branch circuit includes the circuit conductors as well as the equipment between the motor branch-circuit short-circuit and ground-fault protective device and a(n) __________________ motor. a. NEC® Reference: Article 100 (Branch Circuit, Motor) b. Answer: individual

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 3: Boxes and Enclosures®

Solution and Answer Guide

MILLER/S ANDEFUR, ILLUSTRATED GUIDE TO THE NEC®, 21E, ©2024, 9780357766712; UNIT 3: INTRODUCTION TO THE NATIONAL E LECTRICAL CODE®

TABLE OF CONTENTS Unit 3 Competency Test ............................................................................................................................. 1

UNIT 3 COMPETENCY TEST 1. In pull boxes or junction boxes having any dimension over __________________ in., all conductors shall be cabled or racked up in an approved manner. a) 6 b) 12 c) 36 d) 72 a. NEC® Reference: 314.28(B) b. Answer: d) 72; 6 (ft) x 12 (in.) = 72 in.

2. Boxes and conduit bodies in buildings shall be installed so the contained wiring and devices are __________________. a. NEC® Reference: 314.29(A) b. Answer: accessible 3. What are the minimum dimensions for “X” and “Y” in the drawing below if the conductors within the 3-in. conduit are pulled straight through the 3-in. conduit on the opposite wall and the conductors in the 2-in. conduit are pulled through the 2-in. conduit on the adjacent wall?

All conductors are 4 AWG and larger.

a. NEC® Reference: 314.28(A) b. Answer: “X” = 24 in., and “Y” = 12 in. The “X” dimension contains both straight and angle pulls. Use the larger of the two. “X” (straight pull) = 3 x 8 = 24. “X” (angle pull) 3 x 6 + 2 = 20. The “Y” dimension has an angle pull only. “Y” = 2 x 6 = 12.

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 3: Boxes and Enclosures®

4. Outlet boxes that do not enclose devices or utilization equipment shall have a minimum internal depth of __________________ in. a. NEC® Reference: 314.24(A) b. Answer: ½ 5. A 411�16-in. square box that is 21�8 in. deep already contains two receptacles, two internal cable clamps, four 12 AWG THHN copper conductors (two black and two white), two grounding conductors, three wire nuts, two pigtails, and one equipment bonding jumper.

(A flat plaster ring was used to secure the receptacles to the box.) How many more 12 AWG THHN copper conductors can be added to this box? a. NEC® Reference: 314.16 b. Answer: 8. The total 12 AWG conductors permitted by Table 314.16(A) is 18. The flat plaster ring does not provide any additional cubic in. capacity. Two receptacles count as 4 [314.16(B)(4)], two internal cable clamps count as 1 [314.16(B)(2)], four 12 AWG THHN copper conductors count as 4 [314.16(B)(1)], and two grounding conductors count as 1 [314.16(B)(5)] 12 AWG conductors. There are 10 existing 12 AWG conductors. Three wirenuts, two pigtails, and one equipment bonding jumper do not count.

6. In damp or wet locations, surface-type enclosures (within the scope of Article 312) shall be so placed or equipped as to prevent moisture or water from entering and accumulating within the cabinet or cutout box and shall be mounted so there is at least __________________ in. airspace between the enclosure and the wall or other supporting surface. a. NEC® Reference: 312.2 b. Answer: ¼ 7. The minimum thickness in inches for a steel box measuring 6 in. × 4 in. × 3½ in. is __________________ in. a. NEC® Reference: 314.100(B) b. Answer: 0.0625 in.

8. Covers of outlet boxes and conduit bodies having holes through which flexible cord pendants may pass shall be provided with approved __________________ or shall have smooth, well-rounded surfaces on which the cord may bear. a. NEC® Reference: 314.102 b. Answer: bushings

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 3: Boxes and Enclosures®

9. A weatherproof metal junction box measuring 4 in. × 4 in. × 6 in. has been installed to support a luminaire. Two rigid metal conduits have been threaded wrenchtight into the threaded entries of the enclosure. The box has not yet been secured to the brick wall, but both conduits have been strapped to the wall 16 in. from the box. What additional support (from the following list) is required for this box?

I. Two metal screws with plastic anchors II. Two toggle bolts III. Two drive pins a) none b) I or II only c) I or III only d) I, II, or III a. NEC® Reference: 314.23(F) b. Answer: a) none 10. Where permanent barriers are installed in a junction box, each section shall be considered as a(n) __________________. a. NEC® Reference: 314.28(D) b. Answer: separate box 11. What is the maximum number of 12 AWG THW conductors permitted in a 4-in. octagon box that is 1½ in. deep? (The box contains a fixture stud and a hickey.) a. NEC® Reference: 314.16(B)(3) and Table 314.16(A) b. Answer: 4 (6 – 2 = 4) 12. A means must be provided in each metal box for the connection of a(n) __________________. a. NEC® Reference: 314.100(D) b. Answer: equipment grounding conductor 13. Installations within or behind a surface of concrete, tile, gypsum, plaster, or other noncombustible material, including boxes employing a flush-type cover or faceplate, shall be made so that the front edge of the box, plaster ring, extension ring, or listed extender will not be set back of the finished surface more than __________________ in. a. NEC® Reference: 314.20 b. Answer: ¼ 14. Nonmetallic boxes shall be suitable for the lowest __________________ conductor entering the box. a. NEC® Reference: temperature-rated b. Answer: 314.17(B)(4)

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 3: Boxes and Enclosures®

15. An electrician needs to install a surface-mounted, nonmetallic, weatherproof cabinet on the outside of a concrete block building. Since the cabinet must be mounted in a wet location, it must be mounted so there is at least __________________ in. of airspace between the cabinet and the wall. a. NEC® Reference: 312.2 Exception b. Answer: 0 16. How many 14 AWG THW conductors are permitted in a 3 in. × 2 in. × 2½ in. device box? a. NEC® Reference: Table 314.16(A) b. Answer: 6 17. Nonmetallic surface extensions must be secured in place by approved means at intervals not exceeding __________________ in. a. NEC® Reference: 382.30(A) b. Answer: 8 18. A 2½-in. rigid metal conduit enters the back of a pull box with a removable cover on the opposite side. The raceway encloses four 4/0 AWG THHN copper conductors and one 4 AWG equipment grounding conductor. The minimum depth (distance from the entry wall to the cover) for this pull box is __________________ in. a. NEC® Reference: 314.28(A)(2) Exception and Table 312.6(A) b. Answer: 4 19. Where nonmetallic boxes are used with open wiring or concealed knob-and-tube wiring, the conductors must enter the box through __________________. a. NEC® Reference: 314.17(B)(1) b. Answer: individual holes 20. Luminaires weighing no more than __________________ pounds can be supported by boxes (such as device boxes) not specifically designed to support luminaires, provided the luminaire, or its supporting yoke, is secured to the box with at least two No. 6 or larger screws. a. NEC® Reference: 314.27(A)(1) Exception b. Answer: 6 21. For straight pulls, the length of the box shall not be less than __________________ the outside diameter, over sheath, of the largest shielded conductor entering the box if the system voltage is over 1000 volts, nominal. a. NEC® Reference: 314.71(A) b. Answer: 48 times

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 3: Boxes and Enclosures®

22. Approved drainage openings not smaller than __________________ and not larger than __________________ in diameter shall be permitted to be installed in the field in boxes or conduit bodies listed for use in damp or wet locations. a. NEC® Reference: 314.15 b. Answer: 1/8 in., 1/4 in.

23. Unused openings, other than those intended for the operation of equipment, those intended for mounting purposes, or those permitted as part of the design for listed equipment, shall be closed to afford protection __________________ to the wall of the equipment. a. NEC® Reference: 110.12(A) b. Answer: substantially equivalent 24. At least __________________ in. of free conductor (measured from the point in the conduit body where it emerges from its raceway or cable sheath) shall be left at each outlet, junction, and switch point. a. NEC® Reference: 300.14 b. Answer: 6 inches 25. A switch rated for 20 amps will be installed in a device box adjacent to a switch rated for 15 amps. Two 12 AWG THHN copper conductors will be terminated onto the switch rated 20 amps and two 14 AWG THHN copper conductors will be terminated onto the switch rated 15 amps. The required volume allowance for the switch rate 20 amps is __________________ in.3 and the required volume allowance for the switch rate 15 amps __________________ is in.3 a. NEC® Reference: 314.16(B)(4) and Table 314.16(B) b. Answer: 4.5, 4

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 4: Cables

Solution and Answer Guide

MILLER/S ANDEFUR, ILLUSTRATED GUIDE TO THE NEC®, 21E, ©2024, 9780357766712; UNIT 4: CABLES

TABLE OF CONTENTS Unit 4 Competency Test ..................................................................................................................................... 1

UNIT 4 COMPETENCY TEST 1. Nonmetallic-sheathed cable must be secured within __________________ in. from a two-gang plastic device box mounted in a wall. a. NEC® Reference: 334.30 b. Answer: 12 2. Floor-mounted Type FCC cable, cable connectors, and insulating ends shall be covered with carpet squares no larger than __________________ in. square. a. NEC® Reference: 324.41 b. Answer: 39.37 3. Type AC cable shall be supported and secured by staples; cable ties listed, and identified for securement and support; straps, hangers, or similar fittings; or other approved means at intervals not exceeding __________________ ft. a. NEC® Reference: 320.30(B) and (C) b. Answer: 4½ 4. The minimum bending radius for integrated gas-spacer cable with an integral trade size 3-in. conduit is __________________ in. a. NEC® Reference: Table 326.24 b. Answer: 35 5. __________________ is a factory assembly of one or more insulated circuit conductors with or without optical-fiber members enclosed in an armor of interlocking metal tape or a smooth or corrugated metallic sheath. a. NEC® Reference: Article 100 (Cable, Metal Clad [Type MC]) b. Answer: Type MC cable

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 4: Cables

6. Where Type MI cable terminates, a seal shall be provided immediately after stripping to prevent the entrance of __________________ into the insulation. a. NEC® Reference: 332.40(B) b. Answer: moisture 7. Where nonmetallic-sheathed cable is run at angles with joists in unfinished basements, it shall be permissible to secure cables not smaller than three __________________ AWG conductors directly to the lower edges of the joists. a) 12 b) 10 c) 8 d) 6 a. NEC® Reference: 334.15(C) b. Answer: c) 8 8. __________________ is a single or multiconductor solid dielectric insulated cable rated 2001 volts up to and including 35,000 volts, nominal. a. NEC® Reference: Article 100 (Cable, Medium Voltage [Type MV]) b. Answer: Type MV 9. The overall covering of Type UF cable shall be __________________.

I. flame retardant II. suitable for direct burial in the earth III. moisture-, fungus-, and corrosion-resistant a) II only b) I and II only c) II and III only d) I, II, and III a. NEC® Reference: 340.116 b. Answer: d) I, II, and III 10. Power feed, grounding connection, and shield system connection between the FCC system and other wiring systems shall be accomplished in a(n) __________________ identified for this use. a. NEC® Reference: 324.40(D) b. Answer: transition assembly 11. Type AC cable shall be permitted to be unsupported where the cable is not more than in. __________________ in length at terminals where flexibility is necessary. a) 2 b) 6 c) 24 d) 72 a. NEC® Reference: 320.30(D)(2) b. Answer: c) 24. (2 ft = 24 in.).

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 4: Cables

12. The __________________ for the controlled lighting circuit shall be installed at the location where switches control lighting loads that are supplied by a grounded general-purpose branch circuit serving bathrooms, hallways, stairways, and habitable rooms or occupiable spaces as defined in the applicable building code. a. NEC® Reference: 404.2(C) b. Answer: grounded circuit conductor 13. The minimum bending radius for metal-clad (corrugated sheath) cable __________________ is times the external diameter of the metallic sheath. a. NEC® Reference: 330.24(B) b. Answer: seven 14. In both exposed and concealed locations, where a cable or raceway-type wiring method is installed through bored holes in joists, rafters, or wood members, holes shall be bored so that the edge of the hole is not less than __________________ in. from the edges of the wood member. NEC ® Reference Answer a. NEC® Reference: 300.4(A)(1) b. Answer: 1¼ 15. Where run across the top of floor joists or within __________________ ft of the floor or floor joists across the face of rafters or studding, in an attic that has permanent stairs, nonmetallicsheathed cable must be protected by substantial guard strips that are at least as high as the cable. a. NEC® Reference: 334.23 and 320.23(A) b. Answer: 7 ft.

16. Type FCC cable shall be clearly and durably marked on both sides at intervals of not more than 24 in. with the information required by 310.8(A) and with what additional information?

I. Material of conductors and ampacity II. Rated frequency and number of phases III. Maximum temperature rating a) I only b) I and II only c) I and III only d) I, II, and III a. NEC® Reference: 324.120(A) b. Answer: c) I and III only 17. __________________ is a factory assembly of one or more conductors insulated with a highly compressed refractory mineral insulation and enclosed in a liquidtight and gastight continuous copper or alloy steel sheath. a. NEC® Reference: Article 100 (Cable, Mineral-Insulated, Metal-Sheathed [Type MI]) b. Answer: Type MI cable

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 4: Cables

18. Armored cable installed in thermal insulation shall have conductors rated at __________________. The ampacity of the cable installed in these applications shall not exceed that of a 60°C-rated conductor. a) 60°C b) 75°C c) 90°C d) 90°F a. NEC® Reference: 320.80(A) b. Answer: c) 90°C 19. Type MC cable must be supported (and secured) at intervals not exceeding __________________ in. a) 4½ b) 6 c) 54 d) 72 a. NEC® Reference: 330.30(B) and (C) b. Answer: d) 72. 6 (ft) x 12 (in.) = 72 (in.).

20. The maximum ampacity of a 500-kcmil, integrated gas-spacer cable (Type IGS) is __________________ amperes. a. NEC® Reference: Table 326.80 b. Answer: 168 21. Type UF cable, buried under a driveway for a single-family dwelling unit, fed from a 15-ampere, GFCI-protected circuit must have a minimum cover of __________________ in. a) 6 b) 12 c) 18 d) 24 a. NEC® Reference: Table 300.5(A) b. Answer: b) 12 22. In both exposed and concealed locations where nonmetallic-sheathed cables pass through either factory- or field-punched, cut, or drilled slots or holes in metal members, the cable shall be protected by __________________ or __________________ covering all metal edges that are securely fastened in the opening prior to installation of the cable. a. NEC® Reference: 300.4(B)(1) b. Answer: listed bushings, listed grommets 23. A nonmetallic-sheathed cable, passing through a bored hole less than 1¼ in. from the edge of a wood framing member, must be protected by a steel plate (or bushing) at least __________________ in. thick. a. NEC® Reference: 300.4(A)(1) b. Answer: 1�16

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 4: Cables

24. In FCC systems, general-purpose and appliance branch circuits have a maximum current rating of __________________ amperes, while individual branch circuits have a maximum current rating of __________________ amperes. a. NEC® Reference: 324.10(B)(2) b. Answer: 20, 30 25. Type MI cable shall be supported securely at intervals not exceeding __________________ ft by straps, staples, hangers, or similar fittings designed and installed so as not to damage the cable. a. NEC® Reference: 332.30 b. Answer: 6 26. Type UF cable, buried under a one-family dwelling driveway, must have a minimum cover of __________________ in. a. NEC® Reference: Table 300.5(A) b. Answer: 18 27. The provision for a (future) grounded conductor at a switch location that controls lighting loads is to complete a __________________ for electronic lighting control devices. a. NEC® Reference: 404.2(C) Informational Note b. Answer: circuit path 28. A cable assembly can have the white insulated conductor permanently reidentified to indicate its use as an ungrounded conductor but the reidentified conductor cannot be __________________. a) one of the traveler conductors b) the supply conductor from the outlet to the switch c) the return conductor from the switch to the outlet d) any of these conductors a. NEC® Reference: 200.7(C)(1) b. Answer: c) the return conductor from the switch to the outlet 29. Electrical installations in hollow spaces, vertical shafts, and ventilation or air-handling ducts shall be made so that the possible spread of fire or products of combustion will not be __________________. a. NEC® Reference: 300.21 b. Answer: substantially increased 30. A(n) __________________ is a compartment or chamber to which one or more air ducts are connected and that forms part of the air distribution system. a. NEC® Reference: Article 100 (Plenum) b. Answer: plenum

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5

Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 5: Raceways and Conductors

Solution and Answer Guide

MILLER/S ANDEFUR, ILLUSTRATED GUIDE TO THE NEC®, 21E, ©2024, 9780357766712; UNIT 5: RACEWAYS AND CONDUCTORS

TABLE OF CONTENTS Unit 5 Competency Test ............................................................................... Error! Bookmark not defined.

UNIT 5 COMPETENCY TEST 1. Where exposed to the weather, raceways enclosing service-entrance conductors shall be: a) rainproof and arranged to drain. b) watertight and arranged to drain. c) weatherproof and arranged to drain. d) listed or approved for use in wet locations and arranged to drain. a. NEC® Reference: 230.53 b. Answer: d) listed or approved for use in wet 2. Rigid metal conduit shall have a maximum of four __________________ bends between pull points. a. NEC® Reference: 344.24(B) b. Answer: quarter, ¼, or 90° 3. The cross-sectional area of 2-in. EMT is __________________ in.2 a. NEC® Reference: Chapter 9, Table 4. b. Answer: 3.356 4. All cut ends of conduits shall be reamed or otherwise finished to remove rough edges.

Where rigid metal conduit is threaded in the field, a standard cutting die with a __________________ -in. taper per ft (1 in 16) shall be used. a. NEC® Reference: 344.28 b. Answer: ¾ 5. Multioutlet assemblies shall not: I. be installed in hoistways.

II. run within dry partitions.

III. run through dry partitions. a) I only b) III only c) I and II only a. NEC® Reference: 380.12(5) and 380.76 b. Answer: c) I and II only

d) I, II, and III

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1

Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 5: Raceways and Conductors

6. Splices and taps shall be permitted within a metal wireway provided they are accessible.

The conductors, including splices and taps, shall not fill the wireway to more than __________________ of its area at that point. a. NEC® Reference: 376.56(A) b. Answer: 75% 7. A __________________ is defined as a transverse raceway for electric conductors, providing access to predetermined cells of a cellular metal floor, thereby permitting the installation of electric conductors from a distribution center to the cells. a. NEC® Reference: Aticle 100 (Header) b. Answer: header 8. In both exposed and concealed locations, where a cable or raceway-type wiring method is installed through bored holes in joist, rafters, or wood members, holes shall be bored so that the edge of the hole is not less than __________________ in. from the edges of the wood member. a. NEC® Reference: 300.4(A)(1) b. Answer: 1¼ 9. How many 14 AWG THHN conductors, including an equipment grounding conductor, can be installed in a 3�8-in. flexible metal conduit using fittings inside of the conduit? a. NEC® Reference: Table 348.22 b. Answer: 4 10. What is the maximum distance (in ft) between supports for a straight run of 2-in. IMC made up with threaded couplings? a. NEC® Reference: 342.30(B)(2) and Table 344.30(B)(2) b. Answer: 16 11. The sum of cross-sectional areas of all contained conductors and cables at any cross section of a nonmetallic wireway shall not exceed __________________ fill. a. NEC® Reference: 378.22 b. Answer: 20% 12. Where conductors carrying alternating current are installed in ferrous metal raceways, they shall be so arranged as to avoid heating the surrounding metal by__________________. a. NEC® Reference: 300.20(A) b. Answer: induction

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2

Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 5: Raceways and Conductors

13. A __________________ is a type of surface, flush, or freestanding assemblage with a raceway and fittings or other enclosure provided with one or more receptacles, for the purpose of supplying power to utilization equipment. a. NEC® Reference: Article 100 (Multioutlet Assembly) b. Answer: multioutlet assembly 14. Where practicable, contact between dissimilar metals anywhere in the system shall be avoided to eliminate the possibility of __________________. a. NEC® Reference: 342.14 b. Answer: galvanic action 15. What is the maximum number of 4 AWG THHN conductors permitted in 1¼-in. rigid metal conduit? a. NEC® Reference: Informative Annex C, Table C9 b. Answer: 7 16. Where the same 4 AWG conductor enters and then exits a wireway through conduit or tubing, the distance between those raceway entries shall not be less than __________________ times the trade diameter of the largest raceway, when angle or U pulls are made. a. NEC® Reference: 314.28(A)(2) b. Answer: 6 17. What is the maximum allowable ampacity for a 3 AWG THHN copper conductor where the temperature termination on one end is rated 75˚C and the rating of the temperature termination on the other end is unknown? The ambient temperature will not exceed 30˚C and there will not be more than three current-carrying conductors in the raceway. a. NEC® Reference: 110.14(C) (1) and Table 310.16 b. Answer: 85 amps 18. Where an equipment bonding jumper is installed on the outside of a raceway, the length shall not exceed __________________ ft and shall be routed with the raceway or enclosure. a. NEC® Reference: 250.102(E)(2) b. Answer: 6 19. Connections from headers to cabinets and other enclosures, in cellular concrete floor raceways, shall be made by means of: I. listed metal raceways.

II. listed nonmetallic raceways.

IV. listed fittings. a) I only b) I and II only c) I and III only d) I, II, and III a. NEC® Reference: 372.18(B) b. Answer: c) I and III only © 2022 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 5: Raceways and Conductors

20. ENT shall be secured at least every __________________ ft. a. NEC® Reference: 362.30(A) b. Answer: 3 21. IMC encased in a concrete slab, on the first floor of an office building, is considered to be in a __________________ location. a. NEC® Reference: Article 100 (Location, Wet) b. Answer: wet 22. When an outlet from an underfloor raceway is discontinued, the sections of circuit conductors supplying the outlet: a) shall be permitted to be spliced. b) shall be removed from the raceway. c) shall be permitted to be reinsulated. d) shall be handled like abandoned outlets on loop wiring. a. NEC® Reference: 390.57 b. Answer: b) shall be removed from the raceway.

23. RMC, elbows, couplings, and fittings shall be permitted to be installed in concrete, in direct contact with the earth, or in areas subject to severe corrosive influences where protected by __________________ approved for the condition. a. NEC® Reference: 344.10(B)(1) b. Answer: corrosion protection 24. Where installed in raceways, conductors __________________ and larger, not specifically permitted or required elsewhere in the NEC to be solid, shall be stranded. a. NEC® Reference: 310.3(C) b. Answer: 8 AWG 25. In vertical raceways, 3/0 AWG aluminum conductors must be supported if the vertical rise is greater than __________________ ft. a. NEC® Reference: Table 300.19(A) b. Answer: 180 26. Where raceways contain __________________ or larger insulated circuit conductors, and these conductors enter a cabinet, a box, an enclosure, or a raceway, the conductors shall be protected by an identified fitting providing a smoothly rounded insulating surface, unless the conductors are separated from the fitting or raceway by identified insulating materials that are securely fastened in place. a. NEC® Reference: 300.4(G) b. Answer: 4 AWG

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4

Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 5: Raceways and Conductors

27. Nonmetallic wireways shall be supported where run horizontally at intervals not to exceed __________________ ft, and at each end or joint, unless listed for other support intervals. a. NEC® Reference: 378.30(A) b. Answer: 3 ft 28. Horizontal runs of IMC supported by openings through framing members at intervals not exceeding __________________ ft and securely fastened within __________________ ft of termination points shall be permitted. a. NEC® Reference: 342.30(B)(4) b. Answer: 10, 3 29. If a 1¼-in. EMT raceway containing three conductors is already filled to 20%, what is the raceway’s cross-sectional area? a. NEC® Reference: Chapter 9, Table 4 b. Answer: 1.496 sq in.

30. Expansion fittings and telescoping sections of metal raceways shall be made electrically continuous by __________________ or other means. a. NEC® Reference: 250.98 b. Answer: equipment bonding jumpers 31. RMC shall be securely fastened within __________________ ft of each outlet box, junction box, device box, cabinet, conduit body, or other conduit termination. a. NEC® Reference: 344.30(A)(1) b. Answer: 3 32. The maximum distance between supports for 4-in. PVC is __________________ ft. a. NEC® Reference: Table 352.30(B) b. Answer: 7 33. When calculating the maximum number of conductors or cables permitted in a conduit or tubing, all of the same size (total cross-sectional area including insulation), the nexthigher whole number shall be used to determine the maximum number of conductors permitted when the calculation results in a decimal greater than or equal to __________________. a. NEC® Reference: Chapter 9, Note 7 b. Answer: 0.8

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5

Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 5: Raceways and Conductors

34. Where insulated conductors are deflected within a metal wireway, either at the ends or where conduits, fittings, or other raceways or cables enter or leave the wireway, or where the direction of the wireway is deflected greater than __________________, dimensions corresponding to one wire per terminal in Table 312.6(A) shall apply. a. NEC® Reference: 376.23(A) b. Answer: 30° 35. Where the distance above the roof to the bottom of the raceway is less than ¾ in., a temperature adder of __________________ ˚F shall be added to the outdoor temperature to determine the applicable ambient temperature for application of the correction factors in Table 310.15(B)(1)(1) or Table 310.15(B)(1)(2). a. NEC® Reference: 310.15(B)(2) b. Answer: 60 36. Conductors in metal wireways shall be arranged so the power distribution block terminals are __________________ following installation. a. NEC® Reference: 376.56(B)(5) b. Answer: unobstructed 37. As a general rule, __________________ and larger conductors shall be permitted to be connected in parallel (electrically joined at both ends). a. NEC® Reference: 310.10(G)(1) b. Answer: 1/0 AWG

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6

Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 6: General Provisions

Solution and Answer Guide

MILLER/S ANDEFUR, ILLUSTRATED GUIDE TO THE NEC®, 21E, ©2024, 9780357766712; UNIT 6: GENERAL PROVISIONS

TABLE OF CONTENTS Unit 6 Competency Test .................................................................................................................................... 1

UNIT 6 COMPETENCY TEST 1. A duplex receptacle rated 20 amperes can be installed on a __________________ branch circuit. a) 15-ampere b) 20-ampere c) 15- or 20-ampere d) 20- or 25-ampere a. NEC® Reference: Table 210.21(B)(3) b. Answer: b) 20 ampere 2. The continuity of a grounded conductor shall not be dependent on the device in __________________. a) branch circuits not having a grounded conductor b) multiwire branch circuits c) individual branch circuits d) branch circuits a. NEC® Reference: 300.13(B) b. Answer: b) multiwire branch-circuits 3. In dwelling units, receptacle outlets located more than __________________ ft above the floor are not counted in the required number of receptacles along the wall. a. NEC® Reference: 210.52 b. Answer: 5½ 4. At least __________________ in. of free conductor, measured from the point in the box where it emerges from its raceway or cable sheath, shall be left at each outlet, junction, and switch point for splices or the connection of luminaires or devices. a. NEC® Reference: 300.14 b. Answer: 6

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1

Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 6: General Provisions

5. In nonmetallic-sheathed cable, the equipment grounding conductor for 15-, 20-, and 30-ampere branch circuits __________________. a) is required only with aluminum or copper-clad aluminum cable b) must be the same size as the insulated circuit conductors c) may be one size smaller than the insulated circuit conductors d) may be two sizes smaller than the insulated circuit conductors a. NEC® Reference: Table 250.122 b. Answer: b) must be the same size as the insulated circuit conductors 6. A 20-ampere, 125-volt receptacle installed within __________________ ft from the top inside edge of the bowl of the sink shall have ground-fault circuit-interrupter protection for personnel. a. NEC® Reference: 210.8(A)(8) b. Answer: 6 7. What is the minimum number of 120-volt, 15-ampere branch circuits required for the lighting and general use receptacle outlets in a one-family dwelling with an area of 1800 ft2? a. NEC® Reference: 220.41 b. Answer: 3; Multiply 1800 ft2 by 3 volt-ampere: 1800 × 3 = 5400 volt-amperes Find the total amperes: 5400 ÷ 120 = 45 amps Divide 45 amps by 15: 45 ÷ 15 = 3 8. Which of the following is not a standard classification for a branch circuit supplying several loads? a) 20 amperes b) 25 amperes c) 30 amperes d) 50 amperes a. NEC® Reference: 210.18 b. Answer: b) 25 amperes 9. For dwelling units, attached garages, and detached garages with electric power, at least one lighting outlet controlled by a __________________ shall be installed to provide illumination on the exterior side of outdoor entrances or exits with grade-level access. a. NEC® Reference: 210.70(A)(2)(2) b. Answer: listed wall-mounted control device

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2

Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 6: General Provisions

10. Grounding-type receptacles shall be installed only on circuits of the __________________ for which they are rated, except as provided in Tables 210.21(B)(2) and (B)(3).

I. voltage class II. wattage III. current a) I only b) I and III only c) I and II only d) I, II, and III a. NEC® Reference: 406.4(A) b. Answer: b) I and III only 11. Outlet boxes or outlet box systems used as the sole support of a ceiling-suspended (paddle) fan shall be listed, shall be marked by their manufacturer as suitable for this purpose, and shall not support ceiling-suspended (paddle) fans that weigh more than __________________ pounds. a. NEC® Reference: 314.27(C) b. Answer: 70 12. Receptacle outlets in or on floors shall not be counted as part of the required number of receptacle outlets in a dwelling unit unless they are located within __________________ in. of the wall. a. NEC® Reference: 210.52(A)(3) b. Answer: 18 13. For a one-family dwelling that is at grade level, at least one receptacle outlet readily accessible from grade and not more than __________________ ft above grade level shall be installed at the front and back of the dwelling. a. NEC® Reference: 210.52(E)(1) b. Answer: 6½ 14. A luminaire that weighs more than __________________ pounds shall be supported independently of the outlet box, unless the outlet box is listed and marked on the interior of the box to indicate the maximum weight the box shall be permitted to support. a. NEC® Reference: 314.27(A)(2) b. Answer: 50 15. A duplex receptacle rated 15 amperes can be installed on a __________________ ampere general-purpose branch circuit. a. NEC® Reference: Table 210.21(B)(3) b. Answer: 15 or 20 16. A branch circuit that supplies only one utilization equipment is known as a(n) __________________ branch circuit. a. NEC® Reference: Article 100 (Branch-Circuit, Individual) b. Answer: individual

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 6: General Provisions

17. As a general rule, the maximum spacing between receptacle outlets in a dwelling unit is __________________ ft. a. NEC® Reference: 210.52(A)(1) b. Answer: 12 18. A nongrounding-type receptacle has been replaced with a new grounding-type duplex receptacle. The 15-ampere circuit breaker feeding the circuit has been replaced with a 15ampere ground-fault circuit breaker. The new receptacle or its cover plate must be marked __________________ and be visible after installation.

I. “Two-Wire Circuit” II. “No Equipment Ground” III. “GFCI Protected” a) III only b) I and III only c) II and III only d) I, II, and III a. NEC® Reference: 406.4(D)(2)(c) b. Answer: c) II and III only 19. A branch circuit that supplies two or more receptacles or outlets for lighting and appliances is a(n) __________________ branch circuit. a. NEC® Reference: Article 100 (Branch Circuit, General-Purpose) b. Answer: general purpose 20. All switches shall be installed such that the center of the grip of the operating handle of the switch, when in its highest position, is not more than __________________ above the floor or working platform. a. NEC® Reference: 404.8(A) b. Answer: 6 ft 7 in.

21. Switch-controlled receptacles (in lieu of a lighting outlet) are permitted in all but which of the following? a) Bedroom b) Living room c) Dining room d) Hallway a. NEC® Reference: 210.70(A)(1) and (2) b. Answer: d) Hallway 22. A single receptacle rated 50 amperes can be installed on a __________________ -ampere individual branch circuit. a. NEC® Reference: Table 210.21(B)(3) b. Answer: 40 or 50

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4

Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 6: General Provisions

23. In dwelling units, arc-fault circuit-interrupter protection shall not be required for 120-volt, single-phase, 15- and 20-ampere branch circuits supplying outlets or devices installed in __________________. a) kitchens b) bathrooms c) laundry areas d) closets a. NEC® Reference: 210.12(A) b. Answer: b) bathrooms 24. The definition of a branch circuit is __________________. a) the circuit conductors between the service and the subpanel b) the circuit conductors prior to the final overcurrent device protecting the circuit c) the circuit conductors between the final overcurrent device protecting the circuit and the outlet(s) d) the circuit conductors between the final overload device protecting the circuit and the outlet(s) a. NEC® Reference: Article 100 (Branch-Circuit) b. Answer: c) the circuit conductors between the final overcurrent device protecting the circuit and the outlet(s) 25. In dwelling units, a duplex receptacle fed from a multiwire branch circuit must have__________________ as a means of disconnect.

I. two single-pole circuit breakers without identified handle ties II. one double-pole circuit breaker III. two single-pole circuit breakers with identified handle ties a) I only b) I or II only c) II only d) II or III only a. NEC® Reference: 240.15(B) and (B)(1) b. Answer: d) II or III only

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5

Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 7: Specific Provisions

Solution and Answer Guide

MILLER/S ANDEFUR, ILLUSTRATED GUIDE TO THE NEC®, 21E, ©2024, 9780357766712; UNIT 7: Specific Provisions

TABLE OF CONTENTS Unit 7 Competency Test .................................................................................................................................... 1

UNIT 7 COMPETENCY TEST 1. The maximum spacing between kitchen countertop receptacles in a dwelling unit is __________________ ft. a. NEC® Reference: 210.52(C)(1) b. Answer: 4.

2. Hanging luminaires located directly above any part of the bathtub shall be installed so that the luminaire is not less than __________________ ft above the top of the bathtub rim. a. NEC® Reference: 410.10(D) b. Answer: 8 3. A 15-ampere rated duplex receptacle may be installed on __________________ a branch circuit. a) 15-ampere b) 20-ampere c) 15- or 20-ampere d) 15-, 20-, or 25-ampere a. NEC® Reference: Table 210.21(B)(3) b. Answer: c) 15 or 20 ampere 4. The minimum size THHN copper neutral conductor permitted for an 8¾ kW, 240-volt, 3-wire household electric range is __________________. a) 12 AWG b) 10 AWG c) 8 AWG d) 6 AWG a. NEC® Reference: 210.19(C) Exception No. 2 b. Answer: b) 10 AWG 5. Luminaires shall be constructed or installed so that adjacent combustible material will not be subjected to temperatures in excess of __________________ °Fahrenheit. a. NEC® Reference: 410.11 b. Answer: 194

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1

Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 7: Specific Provisions

6. A one-family dwelling has a front entrance on the east side of the house, an attached garage with two 10-ft wide doors on the south side, and a back entrance door on the west side of the house. This one-family dwelling requires __________________ lighting outlet(s) for these outdoor entrances. a. NEC® Reference: 210.70(A)(2) b. Answer: 2.

7. Overcurrent protective devices shall not be located in the vicinity of easily ignitable material such as in __________________. a. NEC® Reference: 240.24(D) b. Answer: clothes closets 8. A single receptacle installed on an individual branch circuit shall have an ampere rating not less than __________________ % of the rating of the branch circuit. a) 125 b) 100 c) 80 d) 50 a. NEC® Reference: 210.21(B)(1) b. Answer: b) 100% 9. Appliance receptacle outlets installed for specific appliances, such as laundry equipment, shall be placed within __________________ ft of the intended location of the appliance. a. NEC® Reference: 210.50(C) b. Answer: 6 10. Tap conductors for household cooking equipment supplied from a 50-ampere branch circuit shall have an ampacity of not less than __________________ amperes. a. NEC® Reference: 210.19(C) Exception No. 1 b. Answer: 20 11. One cooktop and two ovens are connected to one branch circuit in a kitchen of a one-family dwelling. The cooktop has a nameplate rating of 4 kW at 240 volts, while each oven has a nameplate rating of 5.5 kW at 240 volts. The minimum load calculation for this branch circuit is __________________ watts. a. NEC® Reference: Table 220.55, Note 6 b. Answer: 9200; 4 + 5.5 + 5.5 = 15 kW. Increase Column A by 15% (15 – 12 = 3 x 5% = 15%) 8 x 15% = 1.2 kW 8 + 1.2 = 9.2 kW 9.2 x 1000 = 9200 watts.

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 7: Specific Provisions

12. The rating of a single cord- and plug-connected utilization equipment shall not exceed __________________ % of the branch-circuit ampere rating. a. NEC® Reference: 210.23(B)(1) b. Answer: 80 13. A recessed incandescent luminaire with a completely enclosed light source installed in the ceiling of a clothes closet must have a minimum clearance of __________________ in. between the luminaire and the nearest point of the closet storage space. a. NEC® Reference: 410.16(D)(3) b. Answer: 6 14. Where the NEC specifies that one equipment shall be “in sight of” another equipment, the specified equipment shall be visible and not more than __________________ ft distant from the other. a. NEC® Reference: Article 100 (In Sight From) b. Answer: 50 15. In a dwelling unit, a hallway measuring 21½ ft in length requires a minimum of __________________ receptacle outlet(s). a. NEC® Reference: 210.52(H) b. Answer: one 16. A permanently connected dishwasher has a nameplate rating of 780 volt-amperes. The circuit breaker is permitted to serve as the disconnecting means where it is: I. within sight from the dishwasher.

II. lockable in accordance with 110.25.

III. capable of being locked in the closed position. a) I only b) I or III only c) I or II only d) I, II, or III a. NEC® Reference: 422.31(B) b. Answer: c) I or II only 17. Interior stairway lighting outlets shall be controlled by a wall switch at each floor level, where the difference between levels is __________________ steps or more. a. NEC® Reference: 210.70(A)(2)(3) b. Answer: six 18. Supplementary overcurrent devices shall not be required to be __________________. a. NEC® Reference: 240.10 b. Answer: readily accessible

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 7: Specific Provisions

19. The maximum length cord permitted on a built-in dishwasher is __________________ ft. a. NEC® Reference: 422.16(B)(2)(2) b. Answer: 6.5.

20. For a one-family dwelling, at least one receptacle outlet shall be installed in each: I. basement.

II. attached garage.

III. detached garage. a) I only b) I and II only c) II and III only d) I, II, and III a. NEC® Reference: 210.52(G) a. Answer: b) I and II only. A re ceptacle in a detached garage is required only if the garage has electrical power.

21. A refrigerator receptacle can be fed from a: I. 15-ampere individual branch circuit.

II. 20-ampere individual branch circuit.

III. 20-ampere small appliance branch circuit. a) II only b) III only c) II or III d) I, II, or III a. NEC® Reference: 210.52(B)(1) and 210.52(B)(1) Exception No. 2 b. Answer: d) I, II, or III 22. A receptacle installed in an area designated for the installation of laundry equipment and where there are no other receptacles can be a: I. 15-ampere single receptacle.

I. 15-ampere duplex receptacle.

II. 20-ampere duplex receptacle. a) III only b) I or III c) II or III d) I, II, or III a. NEC® Reference: The laundry circuit must be a 20-ampere circuit [210.11(C)(2)]. A single receptacle cannot exceed the rating of the circuit [Article 100]. A duplex receptacle rated 15 amperes is permitted on a 20-ampere circuit [Table 210.21(B)(3)]. b. Answer: 12 23. At least one GFCI-protected receptacle shall be located within __________________ ft from the outside edge of each bathroom sink. a. NEC® Reference: 210.52(D) b. Answer: 3

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 7: Specific Provisions

24. If a receptacle outlet is not installed to serve an island or peninsular countertop in a dwelling unit, __________________. a. NEC® Reference: 210.52(C)(2) a. Answer: Provisions for a future addition of a receptacle outlet must be provided.

25. A branch circuit providing power to a bathroom receptacle may also provide power to: I. two other receptacles, two luminaires, and an exhaust fan in the same bathroom.

II. two other receptacles in the same bathroom and receptacles in two additional bathrooms.

III. one luminaire in the same bathroom and one luminaire in another bathroom. a) I only b) I or II only c) II or III only d) I, II, or III a. NEC® Reference: 210.11(C)(3) and 210.11(C)(3) Exception b. Answer: b) I or II only 26. In addition to the number of branch circuits required by other parts of Article 210, at least one 120-volt, __________________ ampere branch circuit shall be installed to supply receptacle outlets in attached garages and in detached garages with electric power. a. NEC® Reference: 210.11(C)(4) b. Answer: 20 27. Where equipment operating at 1000 volts, nominal, or less to ground and likely to require examination, adjustment, servicing, or maintenance while energized is required by installation instructions or function is located in a crawl space limited access, there shall be an accessible opening not smaller than __________________ in. x __________________ in. a. NEC® Reference: 110.26(A)(4) b. Answer: 22, 30 28. What is the minimum number of 20-ampere small-appliance branch circuits required for a kitchen with 27 linear feet of countertop and an island that measures 2 ft by 6 ft? a. NEC® Reference: 210.11(C)(1) b. Answer: 2 29. The ground-fault circuit interrupter shall be installed in a __________________ location. a. NEC® Reference: 210.8 b. Answer: readily accessible 30. A 125-volt, single-phase, 15- or 20-ampere rated receptacle outlet shall be installed at an accessible location within __________________ ft of heating, air-conditioning, and refrigeration equipment. a. NEC® Reference: 210.63 b. Answer: 25

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 8: Load Calculations

Solution and Answer Guide

MILLER/S ANDEFUR, ILLUSTRATED GUIDE TO THE NEC®, 21E, ©2024, 9780357766712; UNIT 8: Load Calculations

TABLE OF CONTENTS Unit 8 Competency Test .................................................................................................................................... 1

UNIT 8 COMPETENCY TEST 1. It shall be permissible to apply a demand factor of __________________ % to the nameplate rating load of __________________ or more appliances fastened in place rated 1⁄4 hp or greater or 500 watts or greater, other than electric cooking equipment, clothes dryers, spaceheating equipment, air-conditioning equipment, or electric vehicle supply equipment, that are served by the same feeder in a one-family dwelling. a. NEC® Reference: 220.53 b. Answer: 75, four 2. What is the lighting load (before applying demand factors) for a dwelling unit with outside dimensions of 30 ft × 48 ft on the first floor and 22 ft × 42 ft on the second floor? a. NEC® Reference: 220.5(C) and 220.41 b. Answer: 7092 volt-amperes. First, find the total floor area of the house. Multiply the dimensions of each floor and add the two: 30 x 48 = 1440 sq ft (first floor); 22 x 42 = 924 sq ft (second floor); 1440 + 924 = 2364 total sq ft. Next, multiply the total square ft by three (3) volt-amperes per square foot: 2364 x 3 = 7092 volt-amperes.

3. A homeowner wants to add twelve general-purpose receptacle outlets to the electrical drawings before the house is built. What additional load, in volt-amperes, will they add to the service-load calculation? a. NEC® Reference: 220.41 b. Answer: 0 VA 4. In each dwelling unit, the feeder load shall be calculated at __________________ voltamperes for each 2-wire small-appliance branch circuit required by 210.11(C)(1). a. NEC® Reference: 220.52(A) b. Answer: 1500

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 8: Load Calculations

5. What is the minimum calculated service load for two 31⁄2-kW wall-mounted ovens and one 5-kW counter-mounted cooking unit? All of the appliances are supplied from a single branch circuit and are located in the same room of a one-family dwelling. a) 12 kW b) 10 kW c) 8 kW d) 6 kW a. NEC® Reference: Table 220.55 b. Answer: d) 6.6 kW. The question is asking for the service load, not the branch-circuit load. 3.5 + 3.5 + 5 = 12 kW (for three units). Table 220.55, Column B for three units has a demand factor of 55%. 12 x 55% = 6.6 kW. 6. A 4.5-kVA, 240-volt electric clothes dryer contributes __________________ amperes to the neutral load, when calculating the service by the standard method. a. NEC® Reference: 220.54 and 220.61(B) b. Answer: 14.58. 5 kVA (5000 VA) is the minimum dryer load. 5000 ÷ 240 = 20.83 (amperes) 20.83 x 70% = 14.58 (neutral amperes).

7. A one-family dwelling contains the following appliances: a 1-kVA, 115-volt dishwasher; a 1⁄4-horsepower, 115-volt in-sink waste disposer; and a 1⁄3-horsepower, 115-volt trash compactor. Using the standard method, what is the calculated service load, in voltamperes, for these appliances? None of these motors will be the largest motor in this dwelling unit. a. NEC® Reference: 220.53 b. Answer: 2495 volt-amperes; dishwasher 1 x 1000 = 1000 (single-phase motor current ratings are located in Table 430.148); disposer 5.8 x 115 = 667; compactor 7.2 x 115 = 828; 1000 + 667 + 828 = 2495 volt-amperes. Note: No demand factors are allowed on three or fewer fastened-in-place appliances.

8. For one-family dwellings, the service disconnecting means must have a rating of at least __________________ amperes, 3-wire. a. NEC® Reference: 230.79(C) b. Answer: 100 9. A one-family dwelling has a 175-ampere, 240-volt service that is fed with 75°C (167°F) conductors. What is the minimum size copper grounding electrode conductor required? a. NEC® Reference: Table 250.66 b. Answer: 6 AWG. In accordance with Table 310.12(A) the minimum size service conductors for a 175-ampere service are 1/0 AWG copper. Table 250.66 requires a 6 AWG copper grounding electrode conductor for 1/0 service-entrance conductors.

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 8: Load Calculations

10. A one-family dwelling has six 3-kW electric wall heaters (with individual thermostats) and five room air conditioners. Two air conditioners are rated 10.5 amperes at 230 volts, and the other three are rated 7.2 amperes at 115 volts. A service calculation is being performed, using the optional method. How many volt-amperes should be included (after demand factors) for the heating and air conditioning? (Assume heater kW ratings equivalent to kVA.) a. NEC® Reference: 220.82(C) b. Answer: 7314 volt-amperes. Heat = 6 (units) x 3000 (watts) = 18,000; [Four (or more) separately controlled, space heaters have a demand factor of 40%. (220.30(C)(6)]; 18,000 x 40% = 7200 watts (volt-amperes). A/C = 2 (units) x 10.5 (amperes) x 230 (volts) = 4830 volt-amperes; 3 (units) x 7.2 (amperes) x 115 (volts) = 2484 volt-amperes. Airconditioning loads have a demand factor of 100% (220.30(C)(1). Total air-conditioning load 4830 + 2484 = 7314 volt-amperes. The air-conditioning load is larger than the heating load.

11. In each dwelling unit, a feeder load of at least __________________ volt-amperes must be included for each 2-wire laundry branch circuit installed as required by 210.11(C)(2). a. NEC® Reference: 220.52(B) b. Answer: 1500 12. A 12-kW, 240-volt range contributes __________________ watts to the load when calculating the service by the standard method.

Questions 13 through 21 are based on a 120/240-volt, 3-wire, single-phase one-family dwelling containing the following: Floor area . . . . . . . . . . . . . . . . . . . . . . . 2500 ft2 Electric clothes dryer . . . . . . . . . . . . . . . . . . 4 kW, 240-volt Range . . . . . . . . . . . . . . . . . . . . 12 kW, 240-volt Electric heat (two banks at 3 kW each) . . . . 6 kW, 240-volt Water heater . . . . . . . . . . . . . . . 4 kW, 240-volt Air handler (blower motor) . . . . . . . . . . . . 1⁄4 hp, 115-volt Dishwasher . . . . . . . . . . . . . . . 1.5 kW, 120-volt Air-conditioner compressor . . . . . . . . . . . . . 5 hp, 230-volt In-sink waste disposer . . . . . . . 1⁄3 hp, 115-volt Condenser fan motor . . . . . . . . . . . . . . . . . 1⁄6 hp, 115-volt Assume water heater, clothes dryer, range, and electric heat kW ratings equivalent to kVA. a. NEC® Reference: Table 220.55 b. Answer: 8000 Using Part III (the standard method) of Article 220: 13. What is the minimum ampere rating for the service? a. Answer: 145 amperes 14. What is the minimum size service? a. Answer: 150 amperes

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 8: Load Calculations

15. What is the minimum size THWN copper conductor that can be installed as the service (ungrounded) conductor? a. Answer: 1 AWG copper. In accordance with Table 310.12(A), the minimum size service conductors for a 150-ampere service are 1 AWG copper.

16. What is the minimum size grounding electrode conductor? a. Answer: 6 AWG copper Using Part IV (the optional method) of Article 220: 17. What is the minimum ampere rating for the service? a. Answer: 114 amperes 18. What is the minimum size service? a. Answer: 125 amperes 19. What is the minimum size THWN copper conductor that can be installed as the service (ungrounded) conductor? a. Answer: 2 AWG copper. In accordance with Table 310.12(A), the minimum size service] conductors for a 125-ampere service are 2 AWG copper.

20. What is the minimum size grounding electrode conductor? a. Answer: 8 AWG copper Finding the Neutral Load: 21. What is the minimum size THWN copper conductor that can be installed as the neutral conductor? a. Answer: 4 AWG copper

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 8: Load Calculations

Standard Method Load Calculation for One-Family Dwellings Unit 8 . . . Questions 13 through 16

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 8: Load Calculations

Optional Method Load Calculation for One-Family Dwellings Unit 8 . . . Questions 17 through 20

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 8: Load Calculations

Neutral Method Load Calculation for One-Family Dwellings Unit 8 . . . Questions 21

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7

Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 9: Services and Electrical Equipment

Solution and Answer Guide

MILLER/S ANDEFUR, ILLUSTRATED GUIDE TO THE NEC®, 21E, ©2024, 9780357766712; UNIT 9: SERVICES AND ELECTRICAL EQUIPMENT

TABLE OF CONTENTS Unit 9 Competency Test .................................................................................................................................. 1

UNIT 9 COMPETENCY TEST 1. The point of attachment of the service-drop conductors to a building must not be less than __________________ ft above finish grade. a. NEC® Reference: 230.26 b. Answer: 10 2. The supply-side bonding jumper shall not be smaller than the sizes shown in Table __________________ for grounding electrode conductors. a. NEC® Reference: 250.102(C)(1) b. Answer: 250.102(C)(1) 3. Service conductors run above the top level of a window shall be: a) 8 ft above a window. b) considered readily accessible c) 3 ft above a window. d) permitted to be less than 3 ft above the window. a. NEC® Reference: 230.9(A) Exception b. Answer: d) permitted to be less than 3 ft above the window 4. Every circuit breaker having an interrupting rating other than __________________ amperes shall have its interrupting rating shown on the circuit breaker. a. NEC® Reference: 240.83(C) b. Answer: 5000

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 9: Services and Electrical Equipment

5. Energized parts of service equipment that are not enclosed shall be installed on a __________________ and guarded in accordance with 110.18 and 110.27.

I. switchboard II. panelboard III. control board a) II only b) I or II only c) II or III only d) I, II, or III a. NEC® Reference: 230.62(B) b. Answer: d) I, II, or III 6. In addition to the requirement of 408.30, a panelboard shall be protected by an overcurrent protective device having a rating not greater than __________________. a. NEC® Reference: 408.36 b. Answer: that of the panelboard 7. Service-entrance cables shall be supported by straps or other approved means within __________________ of every service head, gooseneck, or connection to a raceway or enclosure. a) 1 ft b) 6 ft c) 12 ft d) 30 ft a. NEC® Reference: 230.51(A) b. Answer: 1 ft 8. Bonding jumpers meeting the other requirements of Article 250 shall be used around impaired connections, such as reducing washers or oversized __________________ knockouts. a. NEC® Reference: 250.92(B) b. Answer: concentric or eccentric 9. Residential 240-volt service-drop conductors must have a vertical clearance above a driveway of at least __________________ ft. a. NEC® Reference: 230.24(B)(2) b. Answer: 12 10. A ground ring used as a grounding electrode and encircling the building, in direct contact with the earth, must consist of at least __________________ ft of bare copper conductor not smaller than 2 AWG. a. NEC® Reference: 250.52(A)(4) b. Answer: 20

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 9: Services and Electrical Equipment

11. Plug fuses of 15-ampere and lower rating shall be identified by a(n) __________________ configuration of the window, cap, or other prominent part to distinguish them from fuses of higher ampere ratings. a. NEC® Reference: 240.50(C) b. Answer: hexagonal 12. Where more than one rod, pipe, or plate grounding electrodes are used, each electrode of one grounding system (including that used for strike termination devices) shall not be less than __________________ ft from any other electrode of another grounding system. a. NEC® Reference: 250.53(B) b. Answer: 6 13. Every circuit and circuit modification in a panelboard shall be legibly identified as to its __________________ purpose or use. a. NEC® Reference: 408.4(A) b. Answer: clear, evident, and specific 14. Service heads on raceways or service-entrance cables and __________________ in serviceentrance cables shall be located above the point of attachment of the service-drop or overhead service conductors to the building or other structure. a. NEC® Reference: 230.54(C) b. Answer: goosenecks 15. The width of the working space in front of electric equipment operating at 1000 volts, nominal, or less to ground shall be the width of the equipment or __________________ in., whichever is greater. a. NEC® Reference: 110.26(A)(2) b. Answer: 30 16. Which of the following is not a true statement concerning an equipment grounding conductor? a) Under certain conditions, equipment grounding conductors shall be required to be larger than circuit conductors supplying the equipment. b) One equipment grounding conductor may serve multiple circuits. c) Under certain conditions, equipment grounding conductors may be run in parallel. d) The size of equipment grounding conductors shall be increased where ungrounded conductors are increased in size. a. NEC® Reference: 250.122 b. Answer: a) Under certain conditions, equipment grounding conductors shall be required to be larger than circuit conductors supplying the equipment.

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 9: Services and Electrical Equipment

17. The minimum height of working space for equipment operating at 1000 volts, nominal, or less to ground and likely to require examination, adjustment, servicing, or maintenance while energized shall be __________________ ft or the height of the equipment, whichever is greater. a. NEC® Reference: 110.26(A)(3) b. Answer: 6½ 18. Service-drop conductors shall have a vertical clearance of not less than _________________ ft above the roof surface. a. NEC® Reference: 230.24(A) b. Answer: 8½ 19. In damp or wet locations, surface-type cabinets, cutout boxes, and meter socket enclosures shall be so placed or equipped as to prevent moisture or water from entering and accumulating within them, and mounted so there is at least __________________ in. airspace between the enclosure and the wall or other supporting surface. a. NEC® Reference: 312.2 b. Answer: ¼ 20. Other equipment or support structures, such as concrete pads, associated with the electrical installation located above or below the electrical installation shall be permitted to extend not more than __________________ beyond the front of the electrical equipment. a) 0 in. b) 6 in. c) 12 in. d) 24 in. a. NEC® Reference: 110.26(A)(3) b. Answer: b) 6 in.

21. What size copper equipment bonding jumper is required for a 200-ampere panelboard located on the load side of the overcurrent device? (The conductors feeding the panelboard are 3/0 AWG copper conductors.) a. NEC® Reference: 250.102(D) and Table 250.122 b. Answer: 6 AWG 22. Plug fuses of the Edison-base type shall be classified at not over 125 volts and __________________ amperes and below. a. NEC® Reference: 240.51(A) b. Answer: 30

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 9: Services and Electrical Equipment

23. A __________________ is a conductor used to connect the system grounded conductor or the equipment to a grounding electrode or to a point on the grounding electrode system. a. NEC® Reference: Article 100 (Grounding Electrode Conductor) b. Answer: grounding electrode conductor 24. If a single rod, pipe, or plate grounding electrode has a resistance to earth of __________________ or less, a supplemental grounding electrode shall not be required. a. NEC® Reference: 250.53(A)(2) Exception b. Answer: 25 ohms 25. A disconnecting means serving a hermetic refrigerant motor compressor shall be selected on the basis of the nameplate rated-load current or branch-circuit selection current, whichever is greater, and locked-rotor current, respectively, of the motor compressor. The ampere rating shall be at least __________________ of the nameplate rated-load current or branch-circuit selection current, whichever is greater. a. NEC® Reference: 440.12(A) and (A)(1) b. Answer: 115% 26. Circuit breakers rated __________________ or less and 1000 volts or less shall have the ampere rating molded, stamped, etched, or similarly marked into their handles or escutcheon areas. a. NEC® Reference: 240.83(B) b. Answer: 100 amperes 27. A dwelling has a 175-ampere service that is fed with THW copper conductors. The service is supplied by a single-phase, 120/240-volt system. What is the minimum size copper grounding electrode conductor? a. NEC® Reference: Table 250.66 b. Answer: 6 AWG. In accordance with Table 310.12(A), the minimum size service conductors are 1/0 AWG copper. The grounding electrode conductor, sized from Table 250.66 for 1/0 copper service-entrance conductors, is 6 AWG copper.

28. The __________________ is the connection between the grounded circuit conductor and the equipment grounding conductor, or the supply-side bonding jumper, or both, at the service. a. NEC® Reference: Article 100 (Bonding Jumper, Main) b. Answer: main bonding jumper

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 9: Services and Electrical Equipment

29. Which of the following is not a standard ampere rating for fuses? a) 25 amperes b) 50 amperes c) 75 amperes d) 601 amperes a. NEC® Reference: 240.6(A) and Table 240.6(A) b. Answer: c) 75 amperes 30. If multiple rod, pipe, or plate electrodes are installed to meet the installation requirements of the grounding electrode system, they shall not be less than __________________ ft apart. a. NEC® Reference: 250.53(A)(3) b. Answer: 6 31. Where the ungrounded supply conductors are larger than 1100 kcmil copper, the main bonding jumper shall have an area not less than __________________ % of the area of the largest ungrounded supply conductor. a. NEC® Reference: 250.28(D)(1) and Table 250.102(C)(1) b. Answer: 12½ 32. Service conductors are the conductors from the service point to the __________________. a. NEC® Reference: Article 100 (Service Conductors) b. Answer: service disconnecting means 33. The minimum depth of working space for a 120/240-volt panelboard, with exposed live parts on one side and grounded parts on the other, shall be at least __________________ ft. a. NEC® Reference: Table 110.26(A) b. Answer: 3 34. Each plate electrode shall expose not less than __________________ ft2 of surface to exterior soil and shall be installed not less than __________________ ft below the surface of the earth. a. NEC® Reference: 250.52(A)(7) and 250.53(A)(5) b. Answer: 2, 2½ 35. Where installed on the outside of a raceway, the length of the equipment bonding jumper shall not exceed __________________ ft and shall be routed with the raceway. a. NEC® Reference: 250.102(E)(2) b. Answer: 6 36. An intersystem bonding termination shall consist of a set of terminals with the capacity for connection of not less than intersystem bonding conductors. a. NEC® Reference: 250.94(A)(2) b. Answer: 3

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 9: Services and Electrical Equipment

37. Where approved, rigid metal conduit shall not be required to be securely fastened within __________________ ft of the service head for above-the-roof termination of a mast. a. NEC® Reference: 344.30(A)(3) b. Answer: 3 38. A service disconnect installed for a one-family dwelling unit as the service disconnect and also as the emergency disconnect shall be marked __________________. a. NEC® Reference: 230.85 b. Answer: Emergency Disconnect, Service Disconnect 39. A grounded conductor must not be connected to of equipment or to equipment grounding conductor(s) or be reconnected to ground on the load side of the service disconnecting means except as otherwise allowed in Article 250. a. NEC® Reference: 250.24(B ) b. Answer: normally non-current-carrying metal parts 40. The grounding and bonding of electrical systems, circuit conductors, surge arresters, surgeprotective devices, and conductive normally non-current-carrying materials (and equipment) must be installed and arranged in a manner that prevents __________________. a. NEC® Reference: 250.6(A) b. Answer: objectionable current 250.6(A) 41. A __________________ is defined as that which is built or constructed, other than equipment. a. NEC® Reference: Article 100 (Structure) b. Answer: structure

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7

Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 10: Comprehensive Provisions

Solution and Answer Guide

MILLER/S ANDEFUR, ILLUSTRATED GUIDE TO THE NEC®, 21E, ©2024, 9780357766712; UNIT 10: COMPREHENSIVE PROVISIONS

TABLE OF CONTENTS Unit 10 Competency Test ................................................................................................................................ 1

UNIT 10 COMPETENCY TEST 1. __________________ is a general term including material, fittings, devices, appliances, luminaires, apparatus, machinery, and the like used as a part of, or in connection with, an electrical installation. a. NEC® Reference: Article 100 (Equipment) b. Answer: Equipment 2. Where a building is supplied by more than one service, or combination of branch circuits, feeders and services, a permanent __________________ or __________________ shall be installed at each service disconnect location denoting all other services, feeders, and branch circuits supplying that building and the area served by each. a. NEC® Reference: 230.2(E) b. Answer: plaque, directory 3. Receptacle outlets installed to serve an island or peninsular countertop in a dwelling unit shall be installed on or above the countertop but not more than __________________ above the countertop. a. NEC® Reference: 210.52(C)(2) and(3) b. Answer: 20 in 4. A(n) __________________ is a device, or group of devices, or other means by which the conductors of a circuit can be disconnected from their source of supply. a. NEC® Reference: Article 100 (Disconnecting Means) b. Answer: disconnecting means

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 10: Comprehensive Provisions

5. A(n) __________________ is a device intended to provide protection from the effects of arc faults by recognizing characteristics unique to arcing and by functioning to de-energize the circuit when an arc fault is detected. a. NEC® Reference: Article 100 [Arc-Fault Circuit Interrupter (AFCI)] b. Answer: arc-fault circuit interrupter 6. Service-drop conductors shall have a vertical clearance of not less than ________________ ft above the roof surface. a. NEC® Reference: 230.24(A) b. Answer: 8 ½ 7. What size copper equipment grounding conductor is required for a circuit having a 40-ampere overcurrent device? a. NEC® Reference: Table 250.122 b. Answer: 10 AWG 8. A 125-ampere feeder will be installed to supply one unit of a multifamily dwelling. The feeder conductors for this panelboard are supplying the entire load associated with this individual dwelling unit. What minimum size copper feeder conductors are required? a. NEC® Reference: 310.12(B) and Table 310.12(A) b. Answer: 2 AWG 9. __________________ in each dwelling unit shall supply only loads within that dwelling unit or loads associated only with that dwelling unit. a. NEC® Reference: 210.25(A) b. Answer: Branch circuits 10. Metal components that are installed in a run of underground installation of nonmetallic raceway(s) and are isolated from possible contact by a minimum cover of __________________ in. to all parts of the metal components shall not be required to be connected to the grounded conductor, supplyside bonding jumper, or grounding electrode conductor. a. NEC® Reference: 250.80 Exception b. Answer: 18 11. Service conductors shall be considered outside of a building or other structure where installed under not less than __________________ in. of concrete beneath a building or other structure. a. NEC® Reference: 230.6 b. Answer: 2

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 10: Comprehensive Provisions

12. What is minimum service demand load (in kW) for an apartment complex containing ten each of the following: 15-kW ranges, 13-kW ranges, 11-kW ranges, and 9-kW ranges? (The service is 120/240 single-phase.) a. NEC® Reference: 220.55 and Table 220.55 b. Answer: 57.75 kW. Note: Use 12 kW for any range rated less than 12 kW. 150 (15 × 10) + 130 (13 × 10) + 120 (12 x 10) + 120 (12 × 10) = 520 (total kW) 520 ÷ 40 = 13 (average kW). Table 220.19, Column C for 40 units is 55 kW (15 + 40) 55 × 5% (Note 2) = 2.75 55 + 2.75 = 57.75 kW. 13. In __________________, remote, central, or automatic control of lighting shall be permitted. a. NEC® Reference: 210.70(A)(2) Exception b. Answer: hallways, stairways, and outdoor entrances 14. Service conductors installed as open conductors shall have a clearance of not less than __________________ ft from fire escapes. a. NEC® Reference: 230.9(A) b. Answer: 3 15. A grounded circuit conductor shall be permitted to be connected to non-currentcarrying metal parts of equipment on the __________________ side of the ac service disconnecting means. a. NEC® Reference: 250.142(A) b. Answer: supply 16. Each unit of a 30-unit apartment building has a 4.5-kW clothes dryer. What is the minimum calculated service load (in kW) for these clothes dryers? (The service is 120/240 single-phase.) a. NEC® Reference: 220.54 and Table 220.54 b. Answer: 47.25 kW. Note: The minimum clothes dryer demand load, in dwelling unit(s), is 5000 watts (5 kW). 5 x 30 x 31.5% = 47.25 kW. 17. Generally, the maximum spacing allowed between receptacle outlets in a multifamily dwelling is __________________ ft. a. NEC® Reference: 210.52(A)(1) b. Answer: 12 18. Overcurrent protective devices shall not be located in the vicinity of __________________, such as in clothes closets. a. NEC® Reference: 240.24(D) b. Answer: easily ignitable material

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 10: Comprehensive Provisions

19. Cabinets and cutout boxes shall have __________________ to accommodate all conductors installed in them without crowding. a. NEC® Reference: 312.7 b. Answer: approved space 20. Where conductors carrying alternating current are installed in ferrous metal enclosures or metal raceways, they shall be arranged so as to avoid heating the surrounding metal by __________________. a. NEC® Reference: 300.20(A) b. Answer: induction 21. __________________ is the highest current at rated voltage that a device is identified to interrupt under standard test conditions. a. NEC® Reference: Article 100 (Interrupting Rating) b. Answer: Interrupting rating 22. Balconies, decks, and porches that are within __________________ in. horizontally of a dwelling unit shall have at least one receptacle outlet accessible from the balcony, deck, or porch. a. NEC® Reference: 210.52(E)(3) b. Answer: 4 23. Enclosures for overcurrent devices shall be mounted in a __________________ position. a. NEC® Reference: 240.33 b. Answer: vertical 24. A metal pole supporting a luminaire, 18 ft above grade, must have a handhole of at least __________________ in. a. NEC® Reference: 410.30(B)(1) b. Answer: 2 x 4 25. Where a building or structure is supplied by more than one service, or any combination of branch circuits, feeders, and services, a __________________ shall be installed at each service disconnect location denoting all other services, feeders, and branch circuits supplying that building or structure and the area served by each. a. NEC® Reference: 230.2(E) b. Answer: permanent plaque or directory

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 10: Comprehensive Provisions

26. __________________ is a combination consisting of a compressor and motor, both of which are enclosed in the same housing, with no external shaft or shaft seals, with the motor operating in the refrigerant. a. NEC® Reference: Article 100 (Hermetic refrigerant motor-compressor) b. Answer: Hermetic refrigerant motor-compressor 27. For permanently connected appliances rated over __________________ volt-amperes, the branch-circuit switch or circuit breaker shall be permitted to serve as the disconnecting means where the switch or circuit breaker is within sight from the appliance or be capable of being locked in the open position in compliance with 110.25. a. NEC® Reference: 422.31(B) b. Answer: 300 28. In a multiple-occupancy building, __________________ must have access to the occupant’s service disconnecting means, unless electric service and electrical maintenance are provided by continuous building management. a. NEC® Reference: 230.72(C) b. Answer: each occupant 29. __________________ is the necessary equipment, usually consisting of a circuit breaker(s) or switch(es) and fuse(s) and their accessories, connected to the serving utility and intended to constitute the main control and disconnect of the serving utility. a. NEC® Reference: Article 100 (Service Equipment) b. Answer: Service equipment 30. No parts of cord-connected luminaires, chain-, cable-, or cord-suspended luminaires, lighting track, pendants, or ceiling-suspended (paddle) fans shall be located within a zone measured __________________ ft horizontally and __________________ ft vertically from the top of the bathtub rim or shower stall threshold. a. NEC® Reference: 410.10(D)(1) b. Answer: 3, 8 31. What is the ac resistance of 500 ft of 1000 kcmil aluminum wire in a steel conduit containing three single conductors? a. NEC® Reference: Chapter 9, Table 9 b. Answer: 0.0125 ohms; 0.025 ÷ 1,000 = 0.000025 × 500 = 0.0125 or 0.025 ÷ 2 = 0.0125

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 10: Comprehensive Provisions

32. At 75°C (167°F), what size copper conductors are required (without exceeding NEC recommendations) to feed a 1⁄4-horsepower, 115-volt, single-phase motor located 230 ft from the source? a. NEC® Reference: 210.19 Informational Note and Table 430.248 b. Answer: 10 AWG copper; cmil = 2 × K × L × I VD = 2 × 12.9 × 230 × 5.8 = 9,976 3.45 = 10 AWG copper 33. Interior metal water piping that is electrically continuous with a metal underground water pipe electrode and is located not more than __________________ ft from the point of entrance to the building, as measured along the water piping, shall be permitted to extend the connection to a grounding electrode. a. NEC® Reference: 250.68(C)(1) b. Answer: 5 34. What is the minimum calculated neutral load (in kW) for twelve 8 kW ranges installed in apartment units? a. NEC® Reference: 220.55, Table 220.55, and 220.61(B) b. Answer: 18.9 kW; Column B = 12 × 8 × 32% = 30.72 Column C = 27.

Use the lesser of Column B or Column C. The neutral load is 70% of the maximum unbalanced load. 27 × 70% = 18.9 220.61(B).

35. What is the percentage of voltage dropped on a circuit using two 10 AWG THW copper, stranded, branch-circuit conductors, 120-ft long, supplying a 21-ampere, 240-volt load? a. NEC® Reference: Chapter 9, Table 8 b. Answer: 2.6%. The answer can be derived from either the Ohm’s Law formula or the voltage drop formula. Both are shown below.

VD = 0.00124 × 120 × 2 × 21 = 6.2496 volts 6.2496 ÷ 240 = 0.026 = 2.6% VD = 2 × K × L × I cmil VD = 2 × 12.8712 × 120 × 21 10,380 = 6.2496 ÷ 240 = 0.026 = 2.6%

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 10: Comprehensive Provisions

36. At least one 125-volt, single-phase, 15- or 20-ampere-rated receptacle outlet shall be installed in an accessible location within __________________ ft of the indoor electrical service equipment in a multifamily dwelling. a. NEC® Reference: 210.63 and 210.63(B)(1) b. Answer: 25 37. In a multifamily dwelling, what is the maximum number of service disconnecting means (for each service) that can be installed at any one location, if separate enclosures with a main service disconnecting means in each enclosure are used? a. NEC® Reference: 230.71(B) b. Answer: 6 38. __________________ is the term for underground conductors between the utility electric supply system and the service point. a. NEC® Reference: Article 100 (Service Lateral) b. Answer: Service lateral

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 11: Load Calculations

Solution and Answer Guide

MILLER/SANDEFUR, ILLUSTRATED GUIDE TO THE NEC®, 21E, ©2024, 9780357766712; UNIT 11: LOAD CALCULATIONS

TABLE OF CONTENTS Unit 11 Competency Test ................................................................................................................................... 1

UNIT 11 COMPETENCY TEST 1. A 125-ampere feeder is supplying a 240-volt panelboard in a multifamily dwelling. The conductors will be XHHW aluminum conductors and all terminations will be rated 75°C (167°F).

What is the minimum size aluminum equipment grounding conductor required? a. NEC® Reference: Table 250.122 b. Answer: 4 AWG aluminum 2. What is the minimum calculated service load (in kW) for 25- to 4.5-kW electric clothes dryers installed in a multifamily dwelling unit? (The service is 120/240-volt, single-phase.) a. NEC® Reference: 220.54 and Table 220.54 b. Answer: 42.5 kW. Note: The minimum minimum load for an electric clothes dryer in a dwelling units, is 5000 watts (5 kW). 5 x 25 x 34% = 42.5 kW. 3. A four-unit apartment building contains the following electric ranges: a 15 kW, a 14 kW, a 10 kW, and a 9 kW. What is the minimum calculated service load for these ranges? a. NEC® Reference: 220.55 and Table 220.55 b. Answer: 17.85 kW. Note: Use 12 kW for any range rated less than 12 kW. 15 + 14 + 12 + 12 = 53 (total kW). 53 ÷ 4 = 13.25 = 13 (average kW). Table 220.55, Column C for 4 units is 17 kW. 17 x 5% (Note 2) = 0.85 17 + 0.85 = 17.85 kW. 4. An eighteen-unit multifamily dwelling contains the following appliances in each unit: a 1-kVA, 115-volt dishwasher; a 1⁄3-horsepower, 115-volt in-sink waste disposer; and a 4500-watt, 230-volt water heater. Using the standard method, what is the minimum calculated neutral load, in volt-amperes, for these appliances? a. NEC® Reference: 220.53 b. Answer: 24,678 volt-amperes. Dishwasher = 1000 VA. Disposer = 7.2 x 115 = 828 VA. Water heater = 0 VA (no neutral load). 1000 + 828 = 1828 VA (each unit). 1828 x 18 x 75% = 24,678 volt-amperes.

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 11: Load Calculations

5. A multifamily dwelling’s service-entrance conductors consist of four paralleled sets of 3/0 AWG THHN copper conductors. What minimum size copper grounding electrode conductor is required? a. NEC® Reference: Table 250.66 b. Answer: 2/0 AWG; 3/0 AWG = 167,800 cmil (Chapter 9, Table 8); 167,800 ÷ 1000 = 167.8 x 4 = 671.2 kcmil (equivalent area). Over 600 through 1100 kcmil copper = 2/0 copper.

6. A 5.4-kVA, 240-volt electric clothes dryer will contribute __________________ amperes to the neutral load, when calculating the service by the standard method. a. NEC® Reference: 220.54 and 220.61(B) a. Answer: 15.75 amperes; 5400 ÷ 240 = 22.5; 22.5 x 70% = 15.75.

7. What is the minimum calculated service load for twenty 6.5-kW electric ranges in a multifamily dwelling? a. NEC® Reference: 220.55 and Table 220.55 b. Answer: 35 kW; Column C (20 units) = 35 kW; Column B = 20 x 6.5 x 28% = 36.4 kW. 8. A service load calculation will need to be performed on a multifamily dwelling. Twelve dwelling units will be supplied by this service. What required load in volt amperes (before applying lighting load demand factors in Table 220.45) shall be added into the load calculation for laundry branch circuits? This multifamily building will have laundry facilities on the premises that will be available for all building occupants to use. a. NEC® Reference: 210.52(F) Exception No. 1 b. Answer: Zero 9. Two paralleled sets of 500-kcmil copper service-entrance conductors supply a multifamily dwelling service disconnecting means. What is the minimum size aluminum grounding electrode conductor required? a. NEC® Reference: Table 250.66 b. Answer: 4/0 AWG aluminum; 500 + 500 = 1000 kcmil (equivalent area). Over 600 through 1100 kcmil copper = 4/0 aluminum.

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 11: Load Calculations

10. A fifty-unit apartment building has a 4.5-kW electric clothes dryer in each apartment. By using the optional method, what is the minimum calculated service load for these appliances?

Questions 11 through 18 are based on a 120/240-volt, 3-wire, single-phase, eight-unit multifamily dwelling. The eight identical units contain the following: Electric heat ............................... 4.2 kW, 240 volt Floor area ...................... 1200 ft2 Range ............................ 83⁄4 kW, 240 volt Air handler (blower motor) ....... 1⁄4 hp, 115 volt Water heater ................. 4 kW, 240 volt Air-conditioner compressor ...... 14 amps, 230 volt Dishwasher ................... 1 kW, 120 volt Condenser fan motor ................ 1⁄6 hp, 115 volt Electric clothes dryer .... 5 kW, 240 volt Assume water heater, clothes dryer, range, and electric heat kW ratings equivalent to kVA. a. NEC® Reference: Table 220.84(B) b. Answer: 58.5 kW; 4.5 (kW) x 50 (units) = 225 (kW); 225 (total kW) x 26% (Table 220.84(B) demand factor) = 58.5 kW. Using Article 220, Parts II and III (the standard method): 11. What is the service demand load for the clothes dryers? a. Answer: 24,000 VA; 5000 (VA) x 8 (units) x 60% = 24,000 VA. 12. What is the service demand load for the cooking appliances? a. Answer: 23,000 VA; Column C (8 units) = 23 kW; Column B = 8 x 8.75 x 36% = 25.2 kW; 23 x 1000 = 23,000 VA. 13. Of the heating or air-conditioning (and associated motors), which is omitted? a. Answer: the heat; 5.8 x 115 = 667 VA (blower); 14 x 230 x 125% = 4025 VA (compressor); 4.4 x 115 = 506 VA (condenser); 4200 + 667 = 4867 x 8 = 38,936 VA (heat); 667 + 4025 + 506 = 5198 x 8 = 41,584 VA (air-condition Include the air-conditioning load, omit the heating load.

14. What is the minimum rating (in amperes) for the service overcurrent device? a. Answer: 600 amperes 15. A parallel run (two sets) of service-entrance conductors will be installed in two raceways. What is the minimum size THWN copper ungrounded conductors that can be used? a. Answer: 350 kcmil copper. Note: Each ungrounded conductor must have a rating of at least 298.5 amperes (597 ÷ 2 = 298.5). 300 kcmil copper has a rating of only 285 amperes. Therefore, 350 kcmil, with a rating of 310 amperes, is the minimum size for a parallel set of conductors.

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 11: Load Calculations

16. What is the minimum rating (in amperes) for the neutral conductors? a. Answer: 305 amperes 17. What is the minimum size THWN copper neutral (grounded) conductors that can be installed? a. Answer: 2/0 copper; 305 ÷ 2 = 152.5 amperes per neutral conductor.

18. What is the minimum size copper grounding electrode conductor?

Questions 19 through 22 are based on a 120/240-volt, 3-wire, single-phase, six-unit multifamily dwelling. The six identical units contain the following: Floor area ................ 1350 ft2 Electric clothes dryer ....................... 4 kW, 240 volt Range ................... 10.6 kW, 240 volt Electric heat (two banks at 3 kW each) .. 6 kW, 240 volt Water heater .............. 4.2 kW, 240 volt Air handler (blower motor) .......... 1⁄3 hp, 115 volt Dishwasher ................. 1.2 kW, 120 volt Air-conditioner compressor .......... 3 hp, 230 volt In-sink waste disposer .. 1⁄3 hp, 115 volt Condenser fan motor .............. 1⁄6 hp, 115 volt Assume water heater, clothes dryer, range, and electric heat kW ratings equivalent to kVA. a. Answer: 2/0 copper Using Article 220, Part IV (the optional method): 19. What is the minimum rating (in amperes) for the service overcurrent device? a. Answer: 400 amperes 20. What is the minimum size THWN copper ungrounded conductors that can be installed? (Do not parallel the conductors.) a. Answer: 600 kcmil copper. Select a copper conductor from Table 310.16 that has an ampacity rating of at least 398 amps. The minimum size service conductors are 600 kcmil copper.

21. What is the minimum size THWN copper neutral (grounded) conductor that can be installed? a. Answer: 300 kcmil copper 22. What is the minimum acceptable size copper grounding electrode conductor? a. Answer: 1/0 copper

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4

Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 12: General Provisions

Solution and Answer Guide

MILLER/SANDEFUR, ILLUSTRATED GUIDE TO THE NEC®, 21E, ©2024, 9780357766712; UNIT 12: GENERAL PROVISIONS

TABLE OF CONTENTS Unit 12 Competency Test ................................................................................................................................... 1

UNIT 12 COMPETENCY TEST 1. In calculating the load of lighting units that employ an autotransformer, the load shall be based on __________________. a. NEC® Reference: 220.11(B) b. Answer: the total ampere ratings of such units.

2. __________________ luminaires used in a show window can be externally wired. a. NEC® Reference: 410.14 b. Answer: Chain-supported 3. Luminaires shall be wired with conductors having insulation suitable for the __________________ to which the conductors will be subjected. a. NEC® Reference: 410.52 b. Answer: environmental conditions, current, voltage, and temperature 4. Systems of illumination utilizing fluorescent lamps, high-intensity discharge (HID) lamps, or neon tubing are defined as __________________. a. NEC® Reference: Article 100 (Electric-Discharge Lighting) b. Answer: electric-discharge lighting 5. The term __________________ is defined as a complete lighting unit consisting of a light source such as a lamp or lamps, together with the parts designed to position the light source and connect it to the power supply. a. NEC® Reference: Article 100 (Luminaire) b. Answer: luminaire

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 12: General Provisions

6. The total rating of utilization equipment fastened in place, other than luminaires, shall not exceed __________________ % of the branch-circuit ampere rating where lighting units, cordand plug-connected utilization equipment not fastened in place, or both, are also supplied. a. NEC® Reference: 210.23(B)(2) b. Answer: 50 7. A metal pole supporting a luminaire must have a handhole not less than __________________ in. with a cover suitable for use in wet locations to provide access to the supply terminations within the pole or pole base. a. NEC® Reference: 410.30(B)(1) b. Answer: 2 x 4 8. Branch circuits that supply neon tubing installations shall not be rated in excess of __________________ amperes. a. NEC® Reference: 600.5(C)(1) b. Answer: 30 9. In accordance with the National Electrical Code, what is the minimum number of receptacles required in a bathroom located in an office occupancy? This bathroom will have two sinks.

There will be a mirror on the wall behind the sinks and the owner does not want the mirror cut. a. NEC® Reference: 210.52(D) and 210.60(A) b. Answer: 0 10. Lampholders of the screw shell type shall be installed for use as lampholders only. Where supplied by a circuit having a __________________ conductor, the __________________ conductor shall be connected to the screw shell. a. NEC® Reference: 410.90 b. Answer: grounded, grounded 11. When calculating track lighting loads for a commercial service, an additional load of __________________ volt-amperes shall be included for every __________________ ft of lighting track or fraction thereof. a. NEC® Reference: 220.46(B) b. Answer: 150, 2

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 12: General Provisions

12. The terminal of an electric-discharge lamp shall be considered as energized where any lamp terminal is connected to a circuit of over __________________. a. NEC® Reference: 410.130(B) b. Answer: 300 volts 13. __________________ luminaires surface mounted over concealed outlet, or pull or junction boxes and designed not to be supported solely by the outlet box shall be provided with suitable openings in back of the luminaire to provide access to the wiring in the boxes. a. NEC® Reference: 410.24(B) b. Answer: Electric-discharge and LED 14. When calculating show-window lighting loads for a commercial service, a load of not less than __________________ shall be included for each linear foot of show window, measured horizontally along its base. a. NEC® Reference: 220.46(A) b. Answer: 200 volt-amperes 15. Twenty-four ft (six 4-ft sections) of track lighting must be installed in a continuous row in a retail store. What is the minimum number of supports required? a. NEC® Reference: 410.154 a. Answer: 7. Two supports in the first 4-foot section and one support in each additional 4-foot section 16. No handhole shall be required in a pole supporting a luminaire that is __________________ ft or less in height abovegrade where the supply wiring method continues without splice or pull point, and where the interior of the pole and any splices are accessible by removing the luminaire. a. NEC® Reference: 410.30(B)(1) Exception No. 1 b. Answer: 8 17. A hermetic refrigerant motor compressor’s branch-circuit short-circuit and groundfault protective device shall be capable of carrying __________________ of the motor’s starting current. a) 100% b) 125% c) 150% d) 175% a. NEC® Reference: 440.22(A) b. Answer: a) 100%. Note: The listed reference states that the device must be capable of carrying the starting current of the motor. The key to this question is starting current, not rated-load current.

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 12: General Provisions

18. Heavy-duty lighting track is lighting track identified for use exceeding __________________. a. NEC® Reference: 410.153 b. Answer: 20 amperes 19. At least __________________ receptacle outlet(s) shall be readily accessible in hotel and motel guest rooms. a. NEC® Reference: 210.60(B) b. Answer: two 20. Flexible cords shall be secured to the undersides of showcases so that a separation between cases not in excess of __________________ in. nor more than __________________ in. between the first case and the supply receptacle will be ensured. a. NEC® Reference: 410.59(C) b. Answer: 2, 12 21. Branch circuits that supply signs and outline lighting systems, other than neon, shall be rated not over __________________. a. NEC® Reference: 600.5(C)(2) b. Answer: 20 amperes 22. No handhole shall be required in a metal pole supporting a luminaire that is __________________ ft or less in height abovegrade that is provided with a hinged base. a. NEC® Reference: 410.30(B)(1) Exception No. 2 b. Answer: 20 23. A single piece of equipment consisting of a multiple receptacle comprising four or more receptacles shall be computed at not less than __________________ per receptacle. a. NEC® Reference: 220.14(I) b. Answer: 90 volt-amperes 24. Luminaires shall not be used as a raceway for circuit conductors unless they are __________________ and marked for use as a raceway. a. NEC® Reference: 410.64(A) b. Answer: listed 25. At least one 125-volt, single-phase, 15- or 20-ampere-rated receptacle outlet shall be installed within 18 in. of the top of each show window. No point along the top of the window shall be farther than __________________ from a receptacle outlet. a. NEC® Reference: 210.62 b. Answer: 6 ft

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 12: General Provisions

26. On hermetic refrigerant motor compressors, the value of branch-circuit selection current will always be __________________ the marked rated-load current.

I. less than II. equal to III. greater than a) I only b) I or II c) II or III d) III only a. NEC® Reference: Article 100 (Branch-Circuit Selection Current) b. Answer: c) II or III 27. Electric-discharge luminaires provided with mogul-base, screw shell lampholders shall be permitted to be connected to branch circuits of __________________ amperes or less by cords complying with 240.5. a. NEC® Reference: 410.62(C)(2) b. Answer: 50 28. The load for the required sign branch circuit for a commercial occupancy shall be calculated at a minimum of __________________. a. NEC® Reference: 220.14(F) b. Answer: 1200 volt-amperes 29. What is the minimum calculated branch-circuit lighting load (in volt-amperes) for a retail store with a floor area of 2,105 ft2? The lighting in this store will be energized for more than 3 hours every day. a. NEC® Reference: Table 220.42(A) b. Answer: 4,000 volt-amperes The unit load per square foot for a retail occupancy is 1.9.

2,105 × 1.9 = 3,999.5 = 4,000 Do not multiply this number by 125 percent.

30. Lighting track shall be securely mounted so that each fastening will be suitable for supporting the maximum weight of luminaires that can be installed. Unless identified for supports at greater intervals, a single section __________________ ft or shorter in length shall have __________________ supports. a. NEC® Reference: 410.154 b. Answer: 4, 2 31. Switches, flashers, and similar devices controlling transformers and electronic power supplies for electric signs shall be rated for controlling inductive loads or have a current rating not less than __________________ of the current rating of the transformer or the electronic power supply. a) 80% b) 100% c) 125% d) 200% a. NEC® Reference: 600.6(B) b. Answer: d) 200%

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 12: General Provisions

32. Conductors of ac and dc circuits rated 1000 volts ac, 1500 volts dc, nominal or less shall be permitted to occupy the same enclosure if: a) all conductors within the enclosure have an insulation rating equal to at least 1000 volts. b) all conductors operating at different voltage levels within the enclosure are separated by a permanent barrier. c) all conductors have an insulation rating equal to at least the maximum circuit voltage applied to any conductor within the enclosure. d) each conductor has an insulation rating equal to at least the maximum circuit voltage applied to each individual conductor within the enclosure. a. NEC® Reference: 300.3(C)(1) b. Answer: c) all conductors have an insulation rating equal to at least the maximum circuit voltage applied to any conductor within the enclosure.

33. Feeder and branch-circuit conductors within __________________ in. of a ballast, LED driver, power supply, or transformer shall have an insulation temperature rating not lower than 90°C (194°F), unless supplying a luminaire marked as suitable for a different insulation temperature. a. NEC® Reference: 410.68 b. Answer: 3 34. The screw shell of all lampholders supplied by a grounded circuit shall be connected to the __________________ conductor. a. NEC® Reference: 410.90 b. Answer: grounded 35. Where connected to a branch circuit having a rating in excess of __________________, lampholders shall be of the heavy-duty type. a. NEC® Reference: 210.21(A) b. Answer: 20 amperes 36. A recessed luminaire that is not identified for contact with insulation shall have all recessed parts spaced at least __________________ in. from combustible materials. a. NEC® Reference: ½ b. Answer: 410.116(A)(1) 37. At least one 125-volt, single-phase, 15- or 20-ampere-rated receptacle outlet shall be installed in an accessible location within __________________ ft of the indoor electrical service equipment in a commercial building. a. NEC® Reference: 210.63 and 210.63(B)(1) b. Answer: 25

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 12: General Provisions

38. Receptacles of 15 and 20 amperes, 125 and 250 volts installed in a wet location shall have an enclosure that is weatherproof whether or not the attachment plug cap is inserted. An outlet box hood installed for this purpose shall be __________________ and shall be identified as __________________. a. NEC® Reference: 406.9(B)(1) b. Answer: listed, extra-duty 39. What is the maximum number of duplex receptacles rated 15-amperes that can be installed on a 20-ampere circuit? a. NEC® Reference: 220.14(I) b. Answer: 13 Receptacles are calculated at 180 volt-amperes per yoke. The rating of each receptacle is 1.5 amperes (180 ÷ 120 = 1.5). Thirteen receptacles are permitted on a 20-ampere overcurrent protective device (20 ÷ 1.5 = 13.3 = 13).

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 13: Nondwelling Load Calculations

Solution and Answer Guide

MILLER/SANDEFUR, ILLUSTRATED GUIDE TO THE NEC®, 21E, ©2024, 9780357766712; UNIT 13: NONDWELLING LOAD CALCULATIONS

TABLE OF CONTENTS Unit 13 Competency Test ................................................................................................................................... 1

UNIT 13 COMPETENCY TEST 1. What is the demand load contribution for a commercial laundry with ten 5-kVA clothes dryers and ten 1.5-kVA washing machines? a. NEC® Reference: 220.14(A) b. Answer: 65 kVA. Use the total kVA load; no derating factors apply to commercial laundries. 10 x 5 = 50 10 x 1.5 = 15 50 + 15 = 65 kVA 2. What is the volt-ampere unit load per square foot for the lighting of a beauty salon? a. NEC® Reference: Table 220.42(A) Barber shops and beauty parlors are considered retail occupancies. b. Answer: 1.9 3. Outlets for heavy-duty lampholders shall be calculated at a minimum of __________________ volt-amperes. a. NEC® Reference: 220.14(E) b. Answer: 600 4. What is the minimum general lighting load for an 11,750-ft2 nightclub with an actual connected lighting load of 14,060 volt-amperes? a. NEC® Reference: Table 220.42(A) Clubs are considered restaurant occupancies. b. Answer: 17,625 volt-amperes. Table 220.42(A) requires 1.5 volt-amperes per square ft (1.5 x 11,750 = 17,625 VA).

5. A restaurant contains the following commercial kitchen equipment: two 12-kW ovens, one 10-kW grill, two 8-kW deep fryers, one 1.2-kW disposer, one 1.5-kW dishwasher, one 10-kW booster heater, and one 4.5-kW water heater. What is the minimum calculated feeder load (in kW) for this equipment? a. NEC® Reference: 220.56 and Table 220.56 b. Answer: 43.68 kW; 12 + 12 + 10 + 8 + 8 + 1.2 + 1.5 + 10 + 4.5 = 67.2 x 65% = 43.68

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 13: Nondwelling Load Calculations

6. For track lighting in a church, a load of not less than __________________ shall be included for every __________________ ft of lighting track or fraction thereof. a. NEC® Reference: 220.46(B) b. Answer: 150 volt-amperes, 2 7. What is the minimum calculated branch-circuit load for 52 duplex receptacle outlets installed in a 9600-ft2 office building? a. NEC® Reference: 220.14(I) and (J) b. Answer: 9600 volt-amperes; 52 x 180 = 9360 VA. Use the larger of calculated load or 1 volt-ampere per square foot.

8. Where it is unlikely that two or more __________________ loads will be in use simultaneously, it shall be permissible to use only the largest load(s) that will be used at one time in calculating the total load of a feeder or service. a. NEC® Reference: 220.60 b. Answer: noncoincident 9. What is the minimum calculated service load for 250 receptacle outlets installed in an office building? a. NEC® Reference: 220.14(I) and Table 220.47 b. Answer: 27,500 volt-amperes; 250 x 180 = 45,000 VA. The first 10,000 volt-amperes is rated 100%, the remainder is multiplied by 50%. 45,000 – 10,000 = 35,000 x 50% = 17,500 + 10,000 = 27,500 10. What is the minimum calculated branch-circuit lighting load for an 8000-ft2 auditorium? a. NEC® Reference: Table 220.42(A) Auditoriums are considered gymnasium-type occupancies. b. Answer: 13,600 volt-amperes. The unit load for a gymnasium-type occupancy is 1.7 volt-amperes per ft2. 8000 x 1.7 = 13,600 11. A manufacturing plant has 320 ft of multioutlet assemblies, of which 60 ft will contain equipment subject to simultaneous use. What is the minimum calculated service load for these multioutlet assemblies? a. NEC® Reference: 220.14(H) and 220.47 b. Answer: 15,080 volt-amperes. 320 – 60 = 260 ÷ 5 = 52 x 180 = 9360 volt-amperes for non-imultaneous use multioutlet assemblies. 60 x 180 = 10,800 volt-amperes for simultaneous use multioutlet assemblies. 9360 + 10,800 = 20,160 volt-amperes (before demand factors). Apply Table 220.47 demand factors to the total multioutlet assembly load. 20,160 – 10,000 = 10,160 x 50% = 5080 + 10,000 = 15,080 volt-amperes.

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 13: Nondwelling Load Calculations

12. A school home economics classroom has twelve 8-kW household ranges. This kitchen equipment is supplied by a 240-volt, single-phase panelboard. What minimum size THW copper conductors are required for this feeder? a. NEC® Reference: Table 220.55, Note 7 and Table 310.16 b. Answer: 2 AWG. Column C = 27 kW; Column B = 30.72 kW (12 x 8 x 32%). Use the smaller rating, 27 kW. 27 x 1000 = 27,000 ÷ 240 = 115 A. Table 310.16 requires 2 AWG THW copper conductors.

13. A motel has 50 guest rooms, each room measuring 18 ft x 30 ft. Each room contains eight duplex receptacles, of which one is GFCI protected. What is the minimum calculated service load for the lighting and receptacle outlets for the guests rooms in this motel? a. NEC® Reference: Table 220.42(A) and Table 220.45 b. Answer: 24,950 volt-amperes. Each room has 540 sq ft (18 x 30). The total area for all 50 rooms is 27,000 sq ft (50 x 540). The guest room general lighting load, computed by Table 220.42(A), is 45,900 volt-amperes (27,000 x 1.7). This load can be derated using Table 220.45. The first 20,000 VA is derated to 12,000 VA (20,000 x 60%). The remainder is derated to 12,950 VA (25,900 x 50%). The total calculated load for the guest rooms in this motel is 24,950 VA (12,000 + 12,950). Note: The room receptacles are included in the general lighting load (220.44).

14. What is minimum calculated branch-circuit load for the show-window lighting for a retail store that has 40 linear feet of show windows? a. NEC® Reference: 220.14(G) b. Answer: 8000 volt-amperes (200 × 40 = 8000) 15. An outlet supplying recessed luminaire(s) shall be calculated based on __________________. a. NEC® Reference: 220.14(D) b. Answer: the maximum volt-ampere rating of the equipment and lamps for which the luminaire(s) is rated 16. For circuits supplying loads consisting of motor-operated utilization equipment that is fastened in place and that has a motor larger than 1⁄8 hp in combination with other loads, the total calculated load shall be based on __________________. a. NEC® Reference: 220.18(A) b. Answer: 125% of the largest motor plus the sum of the other loads 17. In a commercial storage garage, duplex receptacle outlets shall be computed at not less than __________________. a. NEC® Reference: 220.14(I) b. Answer: 180 volt-amperes

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 13: Nondwelling Load Calculations

18. A restaurant contains the following commercial kitchen equipment: one 12-kW range, one 2.8-kW mixer, one 4.2-kW deep fryer, two 0.8-kW soup wells, and one 6-kW water heater. What is the feeder demand load (in kW) for this equipment? a. NEC® Reference: 220.56 b. Answer: 18 kW; 12 + 2.8 + 4.2 + 0.8 + 0.8 + 6 = 26.6 x 65% = 17.29 kW. Note: The feeder demand load can never be smaller than the rating of the two largest pieces of equipment. The two largest pieces (range and water heater) have a total rating of 18 kW. 19. A hospital has 150 patient’s rooms, each room measuring 15 ft x 25 ft. What is the general lighting load (after demand factors) for these rooms? Lighting outlets in these rooms may be energized for more than three hours at a time. a. NEC® Reference: Table 220.42(A) b. Answer: 90,000 volt-amperes; 150 x 15 x 25 = 56,250 (total sq ft). The hospital general lighting load, computed by Table 220.42(A), is 90,000 VA (56,250 x 1.6). This load cannot be derated using Table 220.45. Table 220.42(A) already includes the additional 25% for continuous loads.

20. For circuits supplying lighting units that have ballasts, transformers, autotransformers, or LED drivers, the calculated load shall be based on __________________. a. NEC® Reference: 220.11(B) b. Answer: the total ampere ratings of such units Questions 21 through 30 are based on an office containing the following: Office’s total sq-ft area. . . . . . . . . . . . . . 19,000 ft2 Receptacle outlets. . . . . . . . . . . . . . . . . 200 Multioutlet assemblies... . . . . . . . . . . . 80 ft Multioutlet assemblies... . . . . . . . . . . . 25 ft (simultaneously used) Sign . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 amperes, 120 volt Track lighting. . . . . . . . . . . . . . . . . . . . . . 48 ft Water heater. . . . . . . . . . . . . . . . . . . . . 5 kW, 208 volt Four electric heating units. . . . . . . . . . 10 kW, 208 volt (each) Four air handlers (blower motors). . . . 4 amperes, 208 volt, 3-phase (each) Four air-conditioner compressors... . . . 19.6 amperes, 208 volt, 3-phase (each) Four condenser fan motors . . . . . . . . . . . 3 amperes, 208 volt, 3-phase (each) Assume water heater and electric heat kW ratings equivalent to kVA. The electric supply is a 208-volt, 3-phase, 4-wire service.

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 13: Nondwelling Load Calculations

21. What is the total receptacle (including multioutlet assembly) volt-ampere service load after demand factors are applied? a. NEC® Reference: 220.14(H), 220.14(I) and Table 220.47 b. Answer: 26,690 volt-amperes; 200 x 180 = 36,000 VA (receptacles) 80 ÷ 5 = 16 x 180 = 2880 VA (multioutlet assemblies) 25 x 180 = 4500 VA (simultaneously used multioutlet assemblies); 36,000 + 2880 + 4500 = 43,380 VA (before applying the demond factors of 220.47); 43,380 – 10,000 = 33,380 x 50% = 16,690 + 10,000 = 26,690 VA. 22. What is the minimum calculated branch-circuit lighting load for this 19,000-ft2 office? a. NEC® Reference: Table 220.42 b. Answer: 24,700 volt-amperes; 1.3 x 19,000 = 24,700 VA 23. What is the minimum calculated service load for the track lighting if the lighting will be noncontinuous? a. NEC® Reference: 220.46(B) b. Answer: 3600 volt-amperes; 48 ÷ 2 = 24 x 150 = 3,600 VA 24. What is the minimum calculated branch-circuit load for the sign? (For this question, do not apply the continuous load demand factor.) a. NEC® Reference: 220.14(F) b. Answer: 1800 volt-amperes; 15 x 120 = 1800 VA 25. Which load(s), if any, can be omitted from the service calculation? a. NEC® Reference: 220.60 b. Answer: The four air-conditioner compressor motors and the four condenser fan motors. See question number 26.

26. What is the minimum calculated service load for the heating and air-conditioning equipment? a. NEC® Reference: 220.60 b. Answer: 45,764 volt-amperes. Electric heat: 10,000. Blower motor: 4 × 208 × 1.732 = 1441 VA. Each heating unit = 11,441. Total heating = 45,764 VA. Compressor: 19.6 × 208 × 1.732 × 125% = 8826 VA. Condenser: 3 × 208 × 1.732 = 1081 VA. Air handler: 4 × 208 × 1.732 = 1441 VA. Each air conditioning unit = 11,384 VA. Total air conditioning = 43,392 VA. 27. What is the minimum size service overcurrent protective device required for this office? a. Answer: 350 amperes

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 13: Nondwelling Load Calculations

28. A parallel run (two sets) of service-entrance conductors will be installed in two raceways. What is the minimum size THWN copper ungrounded conductors that can be used? a. Answer: 2/0 AWG. The minimum required ampacity is 304 amperes. A parallel run of 1/0 AWG conductors only has a combined rating of 300 amperes. Therefore, the next larger conductor is required.

29. What is the minimum size THWN copper neutral (grounded) conductors that can be installed? a. Answer: 1/0 copper; Since the conductors are paralleled, each neutral requires 81 amperes (162 ÷ 2). Size 4 AWG copper conductors would carry the current, but the smallest conductor permitted to be connected in parallel is 1/0 AWG. See 250.24(D)(2) and 310.10(G)(1) 30. What is the minimum size copper grounding electrode conductor? a. Answer: 2 AWG. The combined area for the paralleled service-entrance conductors is 266.2 kcmil (133.1 + 133.1).

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 14: Services, Feeders, and Equipment

Solution and Answer Guide

MILLER/SANDEFUR, ILLUSTRATED GUIDE TO THE NEC®, 21E, ©2024, 9780357766712; UNIT 14: SERVICES, FEEDERS, AND EQUIPMENT

TABLE OF CONTENTS Unit 14 Competency Test ........................................................................................................................... 1

UNIT 14 COMPETENCY TEST 1. A separately derived system’s grounding electrode conductor connection can be made at any point from the source to the __________________ system disconnecting means or overcurrent device.

1. NEC® Reference: 250.30(A)(1) and (5) 2. Answer: first 2. For the purposes of Article 408, a 3-pole circuit breaker shall be considered __________________ overcurrent device(s).

1. NEC® Reference: 408.54 2. Answer: three 3. Internal parts of electrical equipment, including busbars, wiring terminals, insulators, and other surfaces, shall not be __________________ by foreign materials such as paint, plaster, cleaners, abrasives, or corrosive residues.

1. NEC® Reference: 110.12(B) 2. Answer: damaged or contaminated 4. An alternate ac power source such as an on-site generator is not a separately derived system if the __________________ is solidly interconnected to a service-supplied system __________________.

1. NEC® Reference: 250.30 Informational Note No. 1 2. Answer: grounded conductor, grounded conductor 5. For equipment rated 1200 amperes or more and over 6 ft wide that contains overcurrent devices, switching devices, or control devices, there shall be at least __________________ entrance(s) into the required working space.

1. NEC® Reference: 110.26(C)(2) 2. Answer: 2 (or one entrance at each end of the working space)

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 14: Services, Feeders, and Equipment

6. A 480-volt transformer, equipped with coordinated thermal overload protection by the manufacturer and arranged to interrupt the primary current, shall be permitted to have primary overcurrent protection rated or set at a current value that is not more than __________________ the rated current of the transformer for a transformer having 8% impedance.

1. NEC® Reference: Table 450.3(B) Note 3 2. Answer: four times (or 400%) 7. The width of the working space in front of the electric equipment shall be the width of the equipment or __________________ in., whichever is greater.

1. NEC® Reference: 110.26(A)(2) 2. Answer: 30 8. Where field-installed wiring passes through an opening in an enclosure, conduit box, or barrier, a __________________ shall be used to protect the conductors from the edges of an opening having sharp edges within generators.

1. NEC® Reference: 445.16 2. Answer: bushing 9. On a switchboard, switchgear, or panelboard supplied from a 4-wire, delta-connected system where the midpoint of one phase winding is grounded, that phase busbar or conductor having the higher voltage to ground shall be durably and permanently marked by an outer finish that is __________________ in color or by other effective means.

1. NEC® Reference: 110.15 2. Answer: orange 10. Ground-fault protection of equipment shall be provided for solidly grounded wye electric services of more than 150 volts to ground, but not exceeding 1000 volts phase-tophase for each service disconnect rated __________________ or more.

1. NEC® Reference: 230.95 2. Answer: 1000 amperes 11. The __________________ conductor of each separately derived system shall be bonded to the nearest accessible point of the interior metal water piping system(s) in the area served by each separately derived system.

1. NEC® Reference: 250.104(D)(1) 2. Answer: grounded 12. Busways shall be securely supported at intervals not exceeding __________________ ft unless otherwise designed and marked.

1. NEC® Reference: 368.30 2. Answer: 5

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 14: Services, Feeders, and Equipment

13. What is the minimum vertical clearance (in ft) for 208Y/120-volt, 3-phase overhead service conductors in a commercial area subject to minimal truck traffic?

1. NEC® Reference: 230.24(B)(4) 2. Answer: 18 ft 14. 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 or contact by persons or objects to a point of danger is the definition of __________________.

1. NEC® Reference: Article 100 (Guarded) 2. Answer: guarded 15. Where the overcurrent device is rated over __________________ amperes, the ampacity of the conductors it protects shall be equal to or greater than the rating of the overcurrent device as defined in 240.6.

1. NEC® Reference: 240.4(C) 2. Answer: 800 16. The enclosure for a panelboard shall have the top and bottom wire-bending space sized in accordance with __________________ for the largest conductor entering or leaving the enclosure. a. NEC® Reference: 408.55(A) 1. Answer: Table 312.6(B)(2) 17. A(n) __________________ is an electrical power supply output, other than a service, having no direct connection(s) to circuit conductors of any other electrical source other than those established by grounding and bonding connections. a. NEC® Reference: Article 100 (Separately Derived System) 2. Answer: separately derived system 18. Dry-type transformers 1000 volts, nominal, or less and not exceeding __________________ shall be permitted in hollow spaces of buildings not permanently closed in by structure. a. NEC® Reference: 450.13(B) 3. Answer: 50 kVA 19. Where rear access is required to work on nonelectrical parts on the back of enclosed equipment, a minimum horizontal working space of __________________ in. shall be provided. a. NEC® Reference: 110.26(A)(1)(a) b. Answer: 30

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 14: Services, Feeders, and Equipment

20. The ampacity of the conductors from the generator output terminals to the first distribution device(s) containing overcurrent protection shall not be less than __________________ % of the nameplate current rating of the generator. a. NEC® Reference: 445.13(A) b. Answer: 115 21. Other equipment that is associated with the electrical installation and is located above or below the electrical equipment shall be permitted to extend not more than __________________ in. beyond the front of the electrical equipment. a. NEC® Reference: 110.26(A)(3) b. Answer: 6 22. For industrial establishments only, omission of overcurrent protection shall be permitted at points where busways are reduced in ampacity, provided that the length of the busway having the smaller ampacity does not exceed __________________ ft and has an ampacity at least equal to one-third the rating or setting of the overcurrent device next back on the line, and provided that such busway is free from contact with combustible material. a. NEC® Reference: 368.17(B) Exception b. Answer: 50 23. Circuit breakers shall be marked with their ampere rating in a manner that will be __________________ after installation. a. NEC® Reference: 240.83(A) b. Answer: durable and visible 24. The minimum height for work space about service equipment, switchboards, switchgear, panelboards, or motor control centers shall be__________________ ft. a. NEC® Reference: 110.26(A)(3) b. Answer: 6½ 25. A 480Y/277-volt switchboard, having exposed live parts on one side and a concrete wall on the other side, requires a minimum working space depth of __________________ in. a. NEC® Reference: Table 110.26(A)(1) b. Answer: 42 (3½ ft = 42 in.)

26. Transformers, other than __________________, shall have a disconnecting means located either in sight of the transformer or in a remote location. Where located in a remote location, the disconnecting means shall be lockable in accordance with 110.25, and its location shall be field-marked on the transformer. a. NEC® Reference: 450.14 b. Answer: Class 2 or Class 3 transformers

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 14: Services, Feeders, and Equipment

27. In other than industrial establishments, where a vertical riser penetrates two or more dry floors, a minimum __________________ in.-high curb shall be installed around all floor openings for riser busways to prevent liquids from entering the opening. a. NEC® Reference: 368.10(C)(2)(b) b. Answer: 4 28. A large single panel, frame, or assembly of panels on which are mounted on the face, back, or both, switches, overcurrent, and other protective devices, buses, and usually instruments is called a __________________. a. NEC® Reference: Article 100 (Switchboard) b. Answer: Switchboard 29. Tapped conductors shall not be permitted for portable generators rated __________________ or less where field wiring connection terminals are not accessible. a. NEC® Reference: 445.13(B) b. Answer: 15 kW 30. The space equal to the width and depth of switchboards, switchgear, panelboards, and motor control centers and extending from the floor to a height of __________________ ft above the equipment or to the structural ceiling, whichever is lower, shall be dedicated to the electrical installation. a. NEC® Reference: 110.26(E)(1)(a) b. Answer: 6 31. For other than a totally enclosed switchboard or switchgear, a space not less than __________________ ft shall be provided between the top of the switchboard or switchgear and any combustible ceiling, unless a noncombustible shield is provided between the switchboard or switchgear and the ceiling. a. NEC® Reference: 408.18(A) b. Answer: 3 32. Where the service-entrance phase conductors are larger than 1100-kcmil copper or 1750-kcmil aluminum, the main bonding jumper shall have an area that is not less than __________________ of the area of the largest phase conductor. a. NEC® Reference: 250.28(D)(1) and Note 1. Under Table 250.102(C)(1) b. Answer: 12½% 33. __________________ is defined as being surrounded by a case, housing, fence, or walls that prevent persons from accidentally contacting energized parts. a. NEC® Reference: Article 100 (Enclosed) b. Answer: enclosed

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 14: Services, Feeders, and Equipment

34. Busways shall be permitted to be extended vertically through dry floors if totally enclosed (unventilated) where passing through and for a minimum distance of __________________ ft above the floor to provide adequate protection from physical damage. a. NEC® Reference: 368.10(C)(2)(a) b. Answer: 6 35. Where a terminal bar is installed in a dry-type transformer, the terminal bar shall be bonded to the enclosure in accordance with 250.12 and shall not be installed on or over any __________________ of the enclosure. a. NEC® Reference: 450.10(A) b. Answer: vented portion 36. In other than dwelling units, a permanent arc flash hazard warning label shall be field or factory applied to service equipment rated __________________ or more. a. NEC® Reference: 110.16(B) b. Answer: 1000 amps 37. Transformers, other than Class 2 or Class 3 transformers, shall have a disconnecting means located either in sight of the transformer or in a remote location. Where located in a remote location, the disconnecting means shall be lockable open in accordance with __________________, and its location shall be field marked on the transformer. a. NEC® Reference: 450.14 b. Answer: 110.25 38. Where electrical equipment rated __________________ amperes or more that contains overcurrent devices, switching devices, or control devices is installed and there is a personnel door(s) intended for entrance to and egress from the working space less than __________________ ft from the nearest edge of the working space, the door(s) shall open at least 90 degrees in the direction of egress and be equipped with listed panic hardware or listed fire exit hardware. a. NEC® Reference: 110.26(C)(3) b. Answer: 800, 25

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 15: Hazardous (Classified) Locations

Solution and Answer Guide

MILLER/SANDEFUR, ILLUSTRATED GUIDE TO THE NEC®, 21E, ©2024, 9780357766712; UNIT 15: HAZARDOUS (CLASSIFIED) LOCATIONS

TABLE OF CONTENTS Unit 15 Competency Test ........................................................................................................................... 1

UNIT 15 COMPETENCY TEST 1. In aircraft hangars, any pit or depression below the level of the hangar floor shall be classified as a __________________ location that shall extend up to said floor level. a. NEC® Reference: 513.3(A) b. Answer: Class I, Division 1 or Zone 1 2. Regardless of the classification of the location in which it is installed, equipment that depends on a single compression seal, diaphragm, or tube to prevent flammable or combustible fluids from entering the equipment, shall be identified for a __________________ location. a. NEC® Reference: 500.8(B)(4) b. Answer: Class I, Division 2 3. A __________________ location is a location in which volatile flammable gases, flammable liquid-produced vapors, or combustible liquid-produced vapors are handled, processed, or used, but in which the 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. a. NEC® Reference: 500.5(B)(2)(1) b. Answer: Class I, Division 2 4. All cut ends of rigid metal conduit (RMC) shall be reamed or otherwise finished to remove rough edges. Where conduit is threaded in the field, a standard cutting die with a __________________ in. taper per foot shall be used. a. NEC® Reference: 344.28 b. Answer: ¾

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 15: Hazardous (Classified) Locations

5. In bulk storage plants, aboveground (fixed roof) tank vents shall be classified as __________________ within 5 ft (1.5 m) of the open end of the vent, extending in all directions. a. NEC® Reference: Table 515.3 b. Answer: Class I, Division 1 or Zone 1 6. In Class I, Division 1 locations, NPT threaded entries into explosionproof equipment shall be made up with at least __________________ threads fully engaged. a. NEC® Reference: 500.8(E)(1) b. Answer: five 7. In Class II, Division 1 locations, boxes and fittings shall be provided with __________________ for connection to conduit or cable terminations, and shall be dusttight. a. NEC® Reference: 502.10(A)(3) b. Answer: threaded bosses 8. A 2-in. threaded RMC is terminating into a 2-in. sealing fitting. The minimum thickness of the sealing compound shall be __________________ in. a. NEC® Reference: 501.15(C)(3) b. Answer: 2 9. In aircraft hangars, the area within __________________ ft horizontally from aircraft power plants or aircraft fuel tanks shall be classified as a Class I, Division 2 or Zone 2 location that shall extend upward from the floor to a level __________________ ft above the upper surface of wings and engine enclosures. a. NEC® Reference: 513.3(C)(1) b. Answer: 5, 5 10. __________________ is defined as equipment enclosed in a manner that will exclude dusts and does not permit arcs, sparks, or heat otherwise generated or liberated inside of the enclosure to cause ignition of exterior accumulations or atmospheric suspensions of a specified dust on or in the vicinity of the enclosure. a. NEC® Reference: Article 100 (Dust-ignitionproof) b. Answer: Dust-ignitionproof 11. Class I locations are those in which __________________ are or may be present in the air in quantities sufficient to produce explosive or ignitible mixtures. a. NEC® Reference: 500.5(B) b. Answer: flammable gases, flammable liquid-produced vapors, or combustible liquid-produced vapors

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 15: Hazardous (Classified) Locations

12. In commercial garages, lamps and lampholders for fixed lighting that is located over lanes through which vehicles are commonly driven shall be located no less than __________________ ft above the floor level. a. NEC® Reference: 511.7(B)(1)(b) b. Answer: 12 13. A __________________ location is a location in which ignitible fibers/flyings are handled, manufactured, or used. a. NEC® Reference: 500.5(D)(1)(b) b. Answer: Class III, Division 1 14. __________________, __________________, __________________, and __________________, __________________ are five acceptable hazardous (classified) location protection techniques for electrical and electronic equipment. a. NEC® Reference: 500.7(A) through (K) b. Answer: Any five of the following: explosion-proof equipment, dust-ignitionproof, dusttight, purged and pressurized, intrinsic safety, nonincendive (circuit, equipment, and component), oil immersion, hermetically sealed, or flammable gas detection system.

15. A(n) __________________ is defined as a circuit other than field wiring in which any arc or thermal effect produced under intended operating conditions of the equipment is not capable, under specified test conditions, of igniting the flammable gas–, vapor–, or dust– air mixture. a. NEC® Reference: Article 100 (Nonincendive Circuit) b. Answer: nonincendive circuit 16. In each conduit run passing from a Class I, Division 2 location into an unclassified area, the sealing fitting shall be located within __________________ ft of the boundary. a. NEC® Reference: 501.15(B)(2) b. Answer: 10 17. For open printing, dipping, and coating processes, electrical wiring and electrical utilization equipment located within __________________ feet of a vapor source shall be suitable for Class I, Division 1 or Class I, Zone 1 locations. a. NEC® Reference: 516.29(2) b. Answer: 5 18. In Class III, Division 2 locations, transformers and capacitors shall comply with NEC Section __________________. a. NEC® Reference: 502.100(B) b. Answer: 503.100

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 15: Hazardous (Classified) Locations

19. An outdoor gasoline dispensing device is considered to be a Class I, Division 2 location up to __________________ in. above grade level, extending __________________ ft horizontally in all directions from dispenser enclosure. a. NEC® Reference: Table 514.3(B)(1) b. Answer: 18, 20 20. In bulk storage plants, the space between __________________ ft and __________________ ft from the open end of an aboveground (fixed roof) tank vent, extending in all directions, is a Class I, Division 2 or Zone 2 location. a. NEC® Reference: Table 515.3 b. Answer: 5, 10 21. A(n) __________________ enclosure is constructed so that dust will not enter under specified test conditions. a. NEC® Reference: Article 100 (Dusttight) b. Answer: dusttight 22. For open printing, dipping, and coating processes, the space __________________ ft above the floor and extending __________________ ft horizontally in all directions from the Class I, Division 1 or Class I, Zone 1 location shall be classified as Class I, Division 2 or Class I, Zone 2, and electrical wiring and electrical utilization equipment located within this space shall be suitable for Class I, Division 2 or Class I, Zone 2 locations, whichever is applicable. a. NEC® Reference: 516.29(4) b. Answer: 3, 20 23. Aircraft energizers shall be designed and mounted so that all electric equipment and fixed wiring will be at least __________________ in. above floor level. a. NEC® Reference: 513.10(C)(1) b. Answer: 18 24. A __________________ location is a location in which combustible dust is in the air under normal operating conditions in quantities sufficient to produce explosive or ignitable mixtures. a. NEC® Reference: 500.5(C)(1)(1) b. Answer: Class II, Division 1 25. For each major repair garage floor, the entire area up to a level of __________________ in. above the floor shall be considered to be a Class I, Division 2 location if ventilation is not provided. a. NEC® Reference: Table 511.3(C) b. Answer: 18

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 15: Hazardous (Classified) Locations

26. A 1⁄2-in. threaded steel IMC is terminating into a 1⁄2-in. sealing fitting. The minimum thickness of the sealing compound shall be __________________ in. a. NEC® Reference: 501.15(C)(3) b. Answer: 5/8 27. The entire area of an aircraft hangar, including any adjacent and communicating areas not suitably separated from the hangar, shall be classified as a Class I, Division 2 or Zone 2 location up to a level __________________ in. above the floor. a. NEC® Reference: 513.3(B) b. Answer: 18 28. Fuel dispensing systems shall be provided with one or more clearly identified emergency shutoff devices or electrical disconnects. Such devices or disconnects shall be installed in approved locations but not less than __________________ ft or more than __________________ ft from the fuel dispensing devices that they serve. a. NEC® Reference: 514.11(A) b. Answer: 20, 100 29. Combustible dust is defined as solid particles that are __________________ micrometers or smaller (i.e., material passing a U.S. No. 35 Standard Sieve as defined in ASTM E11-17, Standard Specification for Woven Wire Test Sieve Cloth and Test Sieves) that can form an explosible mixture when suspended in air at standard atmospheric pressure and temperature. a. NEC® Reference: Article 100 (Combustible Dust) b. Answer: 500 30. Equipment installed in Class III locations shall be able to function at full rating without developing __________________ high enough to cause excessive dehydration or gradual carbonization of accumulated fibers/flyings. a. NEC® Reference: 503.5 b. Answer: surface temperatures

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5

Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 16: Health Care

Solution and Answer Guide

MILLER/SANDEFUR, ILLUSTRATED GUIDE TO THE NEC®, 21E, ©2024, 9780357766712; UNIT 16: HEALTH CARE

TABLE OF CONTENTS Unit 16 Competency Test ........................................................................................................................... 1

UNIT 16 COMPETENCY TEST 1. Low-voltage cables for diagnostic imaging and treatment equipment connecting to oilfilled units that are not completely sealed, such as transformers, condensers, oil coolers, and high-voltage switches, shall have insulation of the __________________ type. a. NEC® Reference: 517.78(B) b. Answer: oil-resistant 2. The life safety and critical branches shall be installed and connected to the alternate power source so that all functions specified herein for the life safety and critical branches are automatically restored to operation within __________________ after interruption of the normal source. a. NEC® Reference: 517.32(B) b. Answer: 10 seconds 3. The equipment-grounding terminal buses of the normal and essential branch-circuit panelboards serving the same individual patient care vicinity shall be connected together with an insulated continuous copper conductor not smaller than __________________. a. NEC® Reference: 517.14 b. Answer: 10 AWG 4. The __________________ is a system of feeders and branch circuits supplying power for task illumination, fixed equipment, select receptacles, and select power circuits serving areas and functions related to patient care and that are automatically connected to alternate power sources by one or more transfer switches during interruption of the normal power source. a. NEC® Reference: Article 100 (Critical Branch) b. Answer: critical branch

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 16: Health Care

5. The cover plates for the electrical receptacles supplied from the life safety and critical branches shall have a distinctive __________________ so as to be readily identifiable. a. NEC® Reference: 517.31(E) b. Answer: color or marking 6. __________________ is a jack or terminal that serves as the collection point for redundant grounding of electric appliances serving a patient care vicinity or for grounding other items in order to eliminate electromagnetic interference problems. a. NEC® Reference: Article 100 (Patient-equipment Grounding Point) b. Answer: Patient-equipment grounding point 7. In any anesthetizing area, all metal raceways and metal-sheathed cables, and all normally non-current-carrying conductive portions of fixed electric equipment, shall be __________________. a. NEC® Reference: 517.62 b. Answer: connected to an equipment grounding conductor 8. A disconnecting means rated for at least __________________ % of the input required for the momentary rating or __________________ % of the input required for the longtime rating of the diagnostic imaging and treatment equipment, whichever is greater, shall be provided in the supply circuit. a. NEC® Reference: 517.72(A) b. Answer: 50, 100.

9. Each patient bed location in a Category 1 space shall be supplied by at least branch __________________ circuit(s). a. NEC® Reference: 517.19(A) b. Answer: 2 10. A patient care vicinity is defined as a space, within a location intended for the examination and treatment of patients, extending __________________ ft beyond the normal location of the patient bed, chair, table, treadmill, or other device that supports the patient during examination and treatment and extending vertically to __________________ ft above the floor. a. NEC® Reference: Article 100 (Patient Care Vicinity) b. Answer: 6, 7½ 11. The line isolation monitor for an isolated power system in a health care facility shall not alarm for a fault hazard of less than __________________ mA or for a total hazard current of less than __________________ mA. a. NEC® Reference: 517.160(B)(1) b. Answer: 3.7, 5

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 16: Health Care

12. Receptacles that are located within patient rooms, bathrooms, playrooms, and activity rooms of pediatric units or spaces with similar risk as determined by the health care facility’s governing body by conducting a risk assessment, other than infant nurseries, shall be __________________ or shall employ a __________________ cover. a. NEC® Reference: 517.18(C) b. Answer: listed and identified as “tamper-resistant”, listed tamper-resistant 13. Category __________________ space is space in which failure of equipment or a system is likely to cause minor injury to patients, staff, or visitors. a. NEC® Reference: Article 100 (Category 2 Space under Patient Care Space) b. Answer: 2 14. In locations where flammable anesthetics are employed, the entire area shall be considered to be a Class I, Division 1 location that shall extend upward to a level __________________ ft above the floor. a. NEC® Reference: 517.60(A)(1) b. Answer: 5 15. In health care facilities with Category 1 spaces, separation of ground-fault protection time-current characteristics shall conform to the manufacturer’s recommendations and shall consider all required tolerances and disconnect operating time to achieve __________________ selectivity. a. NEC® Reference: 517.17(C) b. Answer: 100 percent 16. For portable diagnostic imaging and treatment equipment connected to a 120-volt branch circuit of __________________ or less, a grounding-type attachment plug and receptacle of proper rating shall be permitted to serve as a disconnecting means. a. NEC® Reference: 517.72(C) b. Answer: 30 amperes 17. The __________________ is a system of feeders and branch circuits supplying power for lighting, receptacles, and equipment essential for life safety that is automatically connected to alternate power sources by one or more transfer switches during interruption of the normal power source. a. NEC® Reference: Article 100 (Life Safety Branch) b. Answer: life safety branch

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 16: Health Care

18. A(n) __________________ is used to provide simultaneous service (or treatment) to four or more patients that provides, on an outpatient basis, treatment for patients that renders the patients incapable of taking action for self-preservation under emergency conditions without the assistance of others. a. NEC® Reference: Article 100 (Ambulatory Health Care Occupancy) b. Answer: ambulatory health care occupancy 19. A(n) __________________ is any area of the health care facility that has been designated to be used for the administration of any flammable inhalation anesthetic agents in the normal course of examination or treatment. a. NEC® Reference: flammable anesthetizing location b. Answer: Article 100 (Location, Anesthetizing, Flammable) 20. Each patient bed location in a Category 1 space shall be provided with a minimum of __________________ receptacle(s). a. NEC® Reference: 517.19(B)(1) b. Answer: 14 21. In patient care spaces, all non-current-carrying conductive surfaces of fixed electrical equipment likely to become energized that are subject to personal contact, operating at over __________________, shall be directly connected to an insulated copper equipment grounding conductor that is clearly identified along its entire length by green insulation. a. NEC® Reference: 517.13(B)(1)(3) b. Answer: 100 volts 22. Wall-mounted remote-control stations for remote-control switches operating at __________________ or less shall be permitted to be installed in any anesthetizing location of a health care facility. a. NEC® Reference: 517.63(D) b. Answer: 24 volts 23. A(n) __________________ is a system comprised of alternate sources of power and all connected distribution systems and ancillary equipment, designed to ensure continuity of electrical power to designated areas and functions of a health care facility during disruption of normal power sources, and also designed to minimize disruption within the internal wiring system. a. NEC® Reference: Aricle 100 (Essential Electrical System) b. Answer: essential electrical system

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 16: Health Care

24. In Category 1 spaces, a patient care vicinity shall be permitted to have a patient equipment grounding point. An equipment-bonding jumper, not smaller than __________________, shall be used to connect the grounding terminal of all groundingtype receptacles to the patient equipment grounding point. a. NEC® Reference: 517.19(D) b. Answer: 10 AWG 25. Individual branch circuits shall not be required for portable, mobile, and transportable medical diagnostic imaging and treatment equipment requiring a capacity of not over __________________. a. NEC® Reference: 517.71(B) b. Answer: 60 amperes 26. Each Category 2 space patient bed location shall be provided with a minimum of __________________ receptacle(s). a. NEC® Reference: 517.18(B)(1) b. Answer: eight 27. Category __________________ space is space in which failure of equipment or a system is likely to cause major injury or death to patients, staff, or visitors. a. NEC® Reference: Article 100 (Category 1 Space under Patient Care Space) b. Answer: 1 28. One transfer switch shall be permitted to serve one or more branches or systems in a limited care facility with a continuous load on the switch of __________________ kVA (__________________ kW) or less. a. NEC® Reference: 517.42(B)(2) b. Answer: 150, 120 29. Size 18 or 16 AWG fixture wires as specified in 724.49 and flexible cords shall be permitted for the control and operating circuits of diagnostic imaging and treatment equipment and auxiliary equipment where protected by not larger than __________________ -ampere overcurrent devices. a. NEC® Reference: 517.74(B) b. Answer: 20 30. A flexible cord storage device, within a hazardous (classified) anesthetizing location in a health care facility, shall not subject the cord to bending at a radius of less than __________________ in. a. NEC® Reference: 517.61(A)(7) b. Answer: 3

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 16: Health Care

31. All branch circuits serving patient care spaces in health care facilities shall be provided with an effective __________________ path by installation in a metal raceway system or a cable having a metallic armor or sheath assembly. a. NEC® Reference: 517.13(A) b. Answer: ground-fault current 32. Type 2 essential electrical systems for nursing homes and limited care facilities shall be divided into the following two branches, the __________________ branch and the __________________ branch. a. NEC® Reference: 517.42(A) b. Answer: life safety, equipment 33. The ampacity of supply branch-circuit conductors and the current rating of overcurrent protective devices for diagnostic imaging and treatment equipment shall not be less than __________________% of the momentary rating or __________________% of the longtime rating, whichever is greater. a. NEC® Reference: 517.73(A) b. Answer: 50, 100.

34. In Category 1 spaces, the equipment grounding conductor for special-purpose receptacles, such as the operation of mobile X-ray equipment, shall be extended to the __________________ of branch circuits for all locations likely to be served from such receptacles. a. NEC® Reference: 517.19(H) b. Answer: reference grounding points 35. __________________ is the area in a patient care space where a procedure is performed that is normally subject to wet conditions while patients are present, including standing fluids on the floor or drenching of the work area, either of which condition is intimate to the patient or staff. a. NEC® Reference: Article 100 (Location, Wet Procedure) b. Answer: Wet procedure location 36. Each operating room shall be provided with a minimum of __________________ receptacles. a. NEC® Reference: 517.19(C)(1) b. Answer: 36

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 17: Industrial Locations

Solution and Answer Guide

MILLER/SANDEFUR, ILLUSTRATED GUIDE TO THE NEC®, 21E, ©2024, 9780357766712; UNIT 17: INDUSTRIAL LOCATIONS

TABLE OF CONTENTS Unit 17 Competency Test ........................................................................................................................... 1

UNIT 17 COMPETENCY TEST 1. Terminals of motors and controllers shall be suitably marked or colored where necessary to indicate __________________. a. NEC® Reference: 430.9(A) b. Answer: the proper connections 2. Capacitors containing more than __________________ gallons of flammable liquid shall be enclosed in vaults or outdoor fenced enclosures complying with Article 110, Part III. a. NEC® Reference: 460.3(A) b. Answer: 3 3. Cable tray systems shall not be used in __________________ or where subject to severe physical damage.

I. hoistways II. hazardous locations III. corrosive areas a) I only b) I and II only c) I and III only d) I, II, and III a. NEC® Reference: 392.12 b. Answer: a) I only 4. Wires that are used as crane (or hoist) contact conductors shall be secured at the ends by means of approved strain insulators and shall be mounted on approved insulators so that the extreme limit of displacement of the wire does not bring the latter within less than __________________ in. from the surface wired over. a. NEC® Reference: 610.21(B) b. Answer: 1½

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 17: Industrial Locations

5. Multispeed motors shall be marked with the code letter designating the locked-rotor kilovolt-ampere (kVA) per horsepower (hp) for the highest speed at which the motor __________________. a. NEC® Reference: 430.7(B)(1) b. Answer: can be started 6. The walls and roofs of transformer vaults shall be constructed of materials that have approved structural strength for the conditions with a minimum fire resistance of __________________. a. NEC® Reference: 450.42 b. Answer: 3 hours 7. The two to six service disconnecting means shall be permitted to consist of: I. not more than six sets of circuit breakers mounted in a single enclosure II. not more than six panelboards with a main service disconnecting means in each panelboard enclosure a) I only b) II only c) both I and II d) neither I nor II a. NEC® Reference: 230.71(B) b. Answer: b) II only 8. The residual voltage of capacitor rated 1000 volts or less shall be reduced to __________________, nominal, or less, within __________________ after the capacitor is disconnected from the source of supply. a. NEC® Reference: 460.6(A) b. Answer: 50 volts, 1 minute 9. The disconnecting means for motor circuits rated 1000 volts, nominal, or less, shall have an ampacity rating not less than __________________ of the full-load current rating of the motor. a. NEC® Reference: 430.110(A) b. Answer: 115% 10. Steel cable trays shall not be used as equipment grounding conductors for circuits with ground-fault protection above __________________. a. NEC® Reference: Table 392.60(B), Footnote to table b. Answer: 600 amperes 11. Where no branch-circuit short-circuit and ground-fault protective device is provided with industrial machinery, the rating or setting of the overcurrent protective device shall be based on __________________, as applicable. a. NEC® Reference: 670.4(C) b. Answer: 430.52 and 430.53

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 17: Industrial Locations

12. Branch-circuit conductors supplying one or more units of electroplating equipment shall have an ampacity of not less than __________________ of the total connected load. a. NEC® Reference: 669.5 b. Answer: 125% 13. Vaults containing more than __________________ transformer capacity shall be provided with a drain or other means that will carry off any accumulation of oil or water in the vault unless local conditions make this impracticable. a. NEC® Reference: 450.46 b. Answer: 100 kVA 14. Conductors that supply one or more arc welders shall be protected by an overcurrent device rated or set at not more than __________________ of the conductor ampacity. a. NEC® Reference: 630.12(B) b. Answer: 200% 15. The full-load current of a 25-hp synchronous, 460-volt, 3-phase motor at unity power factor is __________________. a. NEC® Reference: Table 430.250 b. Answer: 26 amperes 16. The ampacity of capacitor circuit conductors, rated 1000 volts or less, shall not be less than __________________ of the rated current of the capacitor. a. NEC® Reference: 460.8(A) b. Answer: 135% 17. Hoist and monorail hoist and their trolleys that are not used as part of an overhead traveling crane shall not require individual motor overload protection, provided the largest motor does not exceed __________________ and all motors are under manual control of the operator. a. NEC® Reference: 610.43(D) b. Answer: 7½ hp 18. A door sill or curb that is of an approved height that will confine the oil from the largest transformer within a transformer vault shall be provided, and in no case shall the height be less than __________________ in. a. NEC® Reference: 450.43(B) b. Answer: 4

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 17: Industrial Locations

19. Branch-circuit conductors that supply a single motor used in a continuous duty application shall have an ampacity of not less than __________________ of the motor full-load current rating as determined by 430.6(A)(1), or not less than specified in 430.22(A) through (G). a. NEC® Reference: 430.22 b. Answer: 125% 20. A(n) __________________ is a power-driven machine (or a group of machines working together in a coordinated manner), not portable by hand while working, that is used to process material by cutting; forming; pressure; electrical, thermal, or optical techniques; lamination; or a combination of these processes. It can include associated equipment used to transfer material or tooling, including fixtures, to assemble/disassemble, to inspect or test, or to package. a. NEC® Reference: Article 100 (Machinery, Industrial) b. Answer: industrial machine 21. Cable trays containing welding cables shall have a permanent sign attached to the cable tray at intervals not greater than __________________ ft. a. NEC® Reference: 630.42(C) b. Answer: 20 22. For raceways terminating at cable trays in supervised industrial facilities, a listed __________________ or adapter shall be used to securely fasten the raceway to the cable tray system. a. NEC® Reference: 392.18(G) b. Answer: cable tray clamp 23. Where the motor-control circuit transformer rated primary current is less than 2 amperes, an overcurrent device rated or set at not more than __________________ of the rated primary current shall be permitted in the primary circuit. a. NEC® Reference: 430.72(C)(4) b. Answer: 500% 24. For cranes and hoists, the dimension of the working space in the direction of access to live parts that are likely to require examination, adjustment, servicing, or maintenance while energized shall be a minimum of __________________ ft. a. NEC® Reference: 610.57 b. Answer: 2½

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 17: Industrial Locations

25. All transformer vault ventilation openings to the indoors shall be provided with automatic closing fire dampers that operate in response to a vault fire. Such dampers shall possess a standard fire rating of not less than __________________. a. NEC® Reference: 450.45(E) b. Answer: 1½ hours 26. The ampacity of the supply conductors for a resistance welder that can be operated at different times, at different values of primary current, or duty cycle shall not be less than __________________ of the rated primary current for manually operated nonautomatic welders. a. NEC® Reference: 630.31(A)(1) b. Answer: 50% 27. Cable trays shall be permitted to extend __________________ through partitions and walls, or __________________ through platforms and floors in wet or dry locations where the installations, complete with installed cables, are made in accordance with the requirements of 300.21. a. NEC® Reference: 392.18(D) b. Answer: transversely, vertically 28. Conductors for a motor used in a short-time, intermittent, periodic, or varying duty application shall have an ampacity of not less than the percentages of the motor nameplate current ratings shown in __________________, unless the authority having jurisdiction grants special permission for conductors of lower ampacity. a. NEC® Reference: 430.22(E) b. Answer: Table 430.22(E) 29. Each doorway leading into a transformer vault from the building interior shall be provided with a tight-fitting door that has a minimum fire rating of __________________. a. NEC® Reference: 450.43(A) b. Answer: 3 hours 30. __________________ shall be placed in all service-entrance motor-control centers to isolate service busbars and terminals from the remainder of the motor control center. a. NEC® Reference: 430.97(E) b. Answer: Barriers

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 17: Industrial Locations

31. Crane, hoist, and monorail hoist motor branch circuits shall be protected by fuses or inverse-time circuit breakers that have a rating in accordance with __________________. c. NEC® Reference: 610.42(A) d. Answer: Table 430.52(C)(1) 32. For a nonautomatically started motor, the overload protection shall be permitted to be shunted or cut out of the circuit during the starting period of the motor if the device by which the overload protection is shunted or cut out shall not be left in the starting position and if fuses or inverse-time circuit breakers rated or set at not over __________________ of the full-load current of the motor are located in the circuit so as to be operative during the starting period of the motor. a. NEC® Reference: 430.35(A) b. Answer: 400% 33. The discharge circuit of a capacitor bank rated 1000 volts or less shall not be connected in which way(s)?

I. Permanently connected to the terminals II. Automatic means of connecting it to the terminals III. Manual means of connecting the discharge circuit a) I or II only b) I or III only c) III only d) I, II, or III a. NEC® Reference: 460.6(B) b. Answer: c) III only 34. Each motor controller shall be capable of starting and stopping the motor it controls and shall be capable of interrupting the __________________ of the motor. a. NEC® Reference: 430.82(A) b. Answer: locked-rotor current 35. When a grounding terminal bar is required to be installed in a dry-type transformer enclosure, the terminal bar shall be bonded to the enclosure in accordance with 250.12 and shall not be installed on or over any __________________ of the enclosure. a. NEC® Reference: 450.10(A) b. Answer: vented portion 36. Tap conductors longer than 25 ft will be installed in a high-bay manufacturing building.

The tap shall be made no less than __________________ ft from the floor. a. NEC® Reference: 240.21(B)(4)(9) b. Answer: 30

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 17: Industrial Locations

37. Service conductors will be connected in parallel and installed in two separate raceways.

The ungrounded supply conductors in each of the two raceways will be 250-kcmil copper.

A single supply-side bonding jumper will be installed to bond the two raceways. What minimum size copper conductor is required? a. NEC® Reference: 250.102(C)(2) and Table 250.102(C)(1) b. Answer: 1/0 38. Circuit conductors other than service conductors shall not be installed in the same __________________ as the service conductors. a. NEC® Reference: 230.7 b. Answer: raceway, cable, handhole enclosure, or underground box 39. Feeder conductors will be connected in parallel and installed in two separate raceways.

The ungrounded feeder conductors in each of the two raceways will be 500-kcmil copper. The overcurrent device protecting these feeder conductors will be an 800-ampere circuit breaker. Wire-type equipment grounding conductor will be installed in each of the two raceways. What minimum size copper equipment grounding conductor will be required in each raceway? a. NEC® Reference:250.122(F)(1)(b) and Table 250.122 b. Answer: 1/0 40. The service supplying power to a small industrial facility will consist of four disconnect switches. The disconnect switches will be separate enclosures with a main service disconnecting means in each enclosure. Each disconnect switch will be rated 225 amperes and the ungrounded service conductors supplying power to each disconnect switch will be 4/0 copper. A common grounding electrode conductor will be installed and a grounding electrode conductor tap will be installed from each disconnect switch to the common grounding electrode conductor. What size grounding electrode conductor tap is required from each disconnect switch to the common grounding electrode conductor? a. NEC® Reference: 250.64(D)(1) and Table 250.66 b. Answer: 2 AWG

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7

Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 18: Special Occupancies

Solution and Answer Guide

MILLER/SANDEFUR, ILLUSTRATED GUIDE TO THE NEC®, 21E, ©2024, 9780357766712; UNIT 18: SPECIAL OCCUPANCIES

TABLE OF CONTENTS Unit 18 Competency Test ........................................................................................................................... 1

UNIT 18 COMPETENCY TEST 1. A(n) __________________ is any building that is of closed construction and is made or assembled in manufacturing facilities on or off the building site for installation, or assembly and installation on the building site, other than manufactured homes, mobile homes, park trailers, or recreational vehicles. a. NEC® Reference: Article 100 (Building, Manufactured) b. Answer: manufactured building 2. Every recreational vehicle site with electrical supply shall be equipped with recreational vehicle site supply equipment with at least __________________ 20-ampere, 125-volt weather-resistant receptacle. a. NEC® Reference: 551.71(A) b. Answer: 1 3. Outdoor mobile home disconnecting means shall be installed so the bottom of the enclosure containing the disconnecting means is not less than __________________ ft above finished grade or the working platform. a. NEC® Reference: 550.32(F) b. Answer: 2 4. A(n) __________________ is an assembly containing one male and two female cord connectors used to connect two loads to one branch circuit. a. NEC® Reference: Article 100 (Two-Fer) b. Answer: two-fer 5. Equipment enclosures, boxes, conduit bodies, and fittings installed in areas of agricultural buildings where excessive __________________ could be present shall be designed to minimize the entrance of __________________. a. NEC® Reference: 547.22 b. Answer: dust, dust

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 18: Special Occupancies

6. All exposed lamps in theater dressing or makeup areas including rooms, where they are less than __________________ ft from the floor, shall be equipped with open-end guards riveted to the outlet box cover or otherwise sealed or locked in place. a. NEC® Reference: 520.72 b. Answer: 8 7. In exhibition halls used for display booths, as in trade shows, the temporary wiring shall be permitted to be installed in accordance with Article __________________. a. NEC® Reference: 518.3 b. Answer: 590 8. In RV parks, a minimum of __________________ % of all recreational vehicle sites with electrical supply shall be equipped with a 30-ampere, 125-volt receptacle. a. NEC® Reference: 551.71(B) b. Answer: 70 9. A(n) __________________ is a factory-assembled structure or structures transportable in one or more sections that are built on a permanent chassis and designed to be used as a dwelling without a permanent foundation where connected to the required utilities, and includes the plumbing, heating, air-conditioning, and electric systems contained therein. a. NEC® Reference: Article 100 (Mobile Home) b. Answer: mobile home 10. The service equipment for a floating building, dock, or marina shall be located on land __________________, but not on or in the structure itself or any other the floating structure. a. NEC® Reference: 555.4 b. Answer: no closer than 5 ft horizontally from and adjacent to the structure served 11. Fixed stage switchboards in television studios shall be __________________ but shall not be required to be located on or adjacent to the stage. a. NEC® Reference: 520.21(2) b. Answer: readily accessible 12. A means to disconnect each portable structure from all ungrounded conductors shall be provided for each carnival ride. The disconnecting means shall be located within sight and within __________________ ft of the operator’s station. a. NEC® Reference: 525.21(A) b. Answer: 6

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 18: Special Occupancies

13. Each motion picture projector, floodlight, spotlight, or similar equipment shall have clear working space not less than __________________ in. wide on each side and at the rear of the equipment. a. NEC® Reference: 540.12 b. Answer: 30 14. The overall length of a mobile home power-supply cord, measured from the end of the cord, including bared leads, to the face of the attachment plug cap shall not be less than __________________ ft and shall not exceed __________________ ft. a. NEC® Reference: 550.10(D) b. Answer: 21, 36½ 15. A 15-ampere duplex receptacle installed in a television audience seating area can be supplied by a __________________-ampere branch-circuit.

I. 15 II. 20 III. 30 a) II only b) I only c) either I or II d) I, II, or III a. NEC® Reference: 520.9 b. Answer: b) I only 16. Single receptacles that provide shore power for boats shall be rated not less than __________________ amperes. a. NEC® Reference: 555.33(A)(4) b. Answer: 30 17. In a multiple occupancy building, occupancy of any room or space for assembly purposes by less than__________________ persons in a building of other occupancy, and incidental to such other occupancy, shall be classified as part of the other occupancy. a. NEC® Reference: 518.2(B) b. Answer: 100 18. In an RV park, open conductors of not over 1000 volts, nominal, shall have a horizontal clearance of not less than __________________ ft and a vertical clearance of not less than __________________ ft in all areas subject to recreational vehicle movement. a. NEC® Reference: 551.79 b. Answer: 3, 18 19. Manufactured building service-entrance conductors shall be installed after erection at the building site unless the __________________ is known prior to manufacture. a. NEC® Reference: 545.6 and Exception b. Answer: point of attachment

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 18: Special Occupancies

20. In a fixed stage switchboard in a theater, the circuit supplying a solid-state dimmer shall not exceed __________________ volts between conductors unless the dimmer is listed specifically for higher voltage operation. a. NEC® Reference: 520.25(C) b. Answer: 150 21. The service equipment shall be mounted in a readily accessible outdoor location, and the __________________ mobile home it serves. a. NEC® Reference: 550.32(A) b. Answer: within sight from 22. Conductors supplying outlets for arc and xenon projectors, in motion picture projection rooms, of the professional type shall not be smaller than __________________ and shall have an ampacity not less than the projector current rating. a. NEC® Reference: 540.13 b. Answer: 8 AWG 23. Each recreational vehicle site electrical service shall be calculated on the basis of not less than __________________ volt-amperes per site equipped with 50-ampere, 208Y/120-volt, or 120/240-volt supply facilities; and __________________ volt-amperes per site equipped with only 20-ampere supply facilities that are not dedicated to tent sites. a. NEC® Reference: 551.73(A) b. Answer: 12,000, 2400 24. Every recreational vehicle site equipped with a __________________ shall also be equipped with a 30-ampere, 125-volt receptacle. a. NEC® Reference: 551.71(C) b. Answer: 50-ampere receptacle 25. A __________________ is a building that floats on water, is moored in a permanent location, and has a premises wiring system served through connection by permanent wiring to an electrical supply system not located on the premises. a. NEC® Reference: Article 100 (Building, Floating) b. Answer: floating building 26. The power supply to the mobile home shall be a feeder assembly consisting of not more than one listed __________________ -ampere mobile power-supply cord or a permanently installed feeder. a. NEC® Reference: 550.10(A) b. Answer: 50

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 18: Special Occupancies

27. Portable structures at carnivals shall be maintained not less than __________________ ft in any direction from overhead conductors operating at 600 volts or less, except for the conductors supplying the portable structure. a. NEC® Reference: 525.5(B)(1) b. Answer: 15 28. A professional-type projector is a type of projector using __________________ film that has a minimum width of __________________ in. and has on each edge __________________ perforations per inch, or a type using carbon arc, xenon, or other light source equipment that develops hazardous gases, dust, or radiation. a. NEC® Reference: Article 100 (Projector, Professional-Type) b. Answer: 35- or 70-mm, 13/8, 5.4 29. In closed construction of manufactured buildings, cables shall be permitted to be secured only at cabinets, boxes, or fittings where __________________ or smaller conductors are used and protection against physical damage is provided. a. NEC® Reference: 545.4(B) b. Answer: 10 AWG 30. All cables installed in agricultural buildings shall be secured within __________________ in. of each cabinet, box, or fitting. a. NEC® Reference: 547.21 b. Answer: 8 31. A minimum of __________________ % of existing and __________________ % of all new recreational vehicle sites with electrical supply shall each be equipped with a 50-ampere, 125/250-volt receptacle. a. NEC® Reference: 551.71(C) b. Answer: 20, 40 32. Footlights, border lights, and proscenium side lights, in theaters, shall be arranged so that no branch circuit supplying such equipment will carry a load exceeding __________________. a. NEC® Reference: 520.41(A) b. Answer: 20 amperes 33. A meeting room that is not more than 1000 ft2 with any floor dimension that is at least __________________ ft or greater in any direction and that has a floor area of at least 215 ft2 (20 m2) shall have at least one floor receptacle outlet, or at least one floor outlet to serve receptacle(s), located at a distance not less than __________________ ft from any fixed wall for each 215 ft2 (20 m2) or major portion of floor space. a. NEC® Reference: 210.65(B)(2) b. Answer: 12, 6 © 2024 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 19: Specific Equipment

Solution and Answer Guide

MILLER/SANDEFUR, ILLUSTRATED GUIDE TO THE NEC®, 21E, ©2024, 9780357766712; UNIT 19: SPECIFIC EQUIPMENT

TABLE OF CONTENTS Unit 19 Competency Test ........................................................................................................................... 1

UNIT 19 COMPETENCY TEST 1. Storable swimming pools are pools installed __________________ that are intended to be stored when not in use. a. NEC® Reference: Article 100 b. Answer: entirely on or above the ground 2. Overcurrent protection for feeders and branch circuits supplying electric vehicle supply equipment (EVSE) and wireless power transfer equipment (WPTE), including bidirectional EVSE, and WPTE shall be sized for __________________ duty and shall have a rating of not less than __________________ % of the maximum load of the equipment. a. NEC® Reference: 625.41 b. Answer: continuous, 125 3. A clearly labeled emergency shutoff or control switch for the purpose of stopping the motor(s) that provide power to the recirculation system and jet system shall be installed at a point readily accessible to the users and at least __________________ ft away, adjacent to, and within sight from every spa or hot tub installed in other than single family dwelling units. a. NEC® Reference: 680.41(A) b. Answer: 5 4. Transformers and power supplies used for the supply of underwater luminaires in swimming pools shall incorporate either a transformer of the isolated winding type with an ungrounded secondary that has a __________________ between the primary and secondary windings or one that incorporates an approved system of double insulation between the primary and secondary windings. a. NEC® Reference: 680.23(A)(2) b. Answer: grounded metal barrier

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 19: Specific Equipment

5. Duty on elevator driving machine motors shall be rated as __________________. a. NEC® Reference: 620.61(B)(1) b. Answer: intermittent 6. Not more than __________________ ft of high-voltage cable shall be permitted in nonmetallic conduit from a high-voltage terminal of a neon transformer (over 1000 volts, nominal) supply to the first neon tube. a. NEC® Reference: 600.32(J)(1)(2) b. Answer: 50 7. All fixed metal parts that are within __________________ ft horizontally of the inside walls of a permanently installed swimming pool and within __________________ ft above the pool’s maximum water level shall be bonded. a. NEC® Reference: 680.26(B)(7) b. Answer: 5, 12 8. All receptacles within __________________ ft of a therapeutic tub shall be protected by a ground-fault circuit interrupter. a. NEC® Reference: 680.62(E) b. Answer: 6 9. All live parts of electrical apparatus in elevator hoistways, at the landings, in or on the cars of elevators and dumbwaiters, in the wellways or the landings of escalators or moving walkways, or in the runways and machinery spaces of platform lifts and stairway chairlifts shall be __________________. a. NEC® Reference: 620.4 b. Answer: enclosed to protect against accidental contact 10. Unless specifically listed and marked for the location, the coupling means of the electric vehicle supply equipment (EVSE) shall be stored or located at a height of not less than __________________ in. above the floor level for indoor locations and __________________ in. above the grade level for outdoor locations. a. NEC® Reference: 625.50 b. Answer: 18, 24 11. A(n) __________________ is a structure designed to support a wet-niche luminaire assembly and intended for mounting in a pool or fountain structure. a. NEC® Reference: Article 100 (Forming Shell) b. Answer: forming shell

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 19: Specific Equipment

12. Switches, flashers, and similar devices controlling transformers and electronic power supplies for electric signs shall be rated for controlling inductive loads or have a current rating not less than __________________ of the current rating of the transformer or the electric power supply. a) 80%

b) 100%

c) 125%

d) 200%

a. NEC® Reference: 600.6(B) b. Answer: d) 200% 13. Audio system equipment supplied by branch-circuit power shall not be placed horizontally within __________________ ft of the inside wall of a pool, spa, hot tub, or fountain, nor within __________________ ft of the prevailing or tidal high water mark. a. NEC® Reference: 640.10(A) b. Answer: 5, 5 14. Where a permanently installed pool is installed, at least one 125-volt, 15- or 20-ampere receptacle on a general-purpose branch circuit shall be located a minimum __________________ of ft from and not more than __________________ ft from the inside wall of the pool. a. NEC® Reference: 680.22(A)(1) b. Answer: 6, 20 15. The voltage at a fire pump controller’s line terminals shall not drop more than __________________ below normal (controller-rated voltage) under motor starting conditions unless special conditions are met. a. NEC® Reference: 695.7(A) b. Answer: 15% 16. Luminaires located over a spa or within 5 ft (1.5 m) from the inside walls of the spa shall be permitted to be not less than __________________ ft above the maximum water level where protected by a GFCI. a. NEC® Reference: 680.43(B)(1)(b) b. Answer: 7½ 17. Traveling cables that are suitably supported and protected from physical damage shall be permitted to be run without the use of a raceway from inside the hoistway, to elevator controller enclosures and to elevator car and machine room, control room, machinery space, and control space connections that are located outside the hoistway for a distance not exceeding __________________ ft in length as measured from the first point of support on the elevator car or hoistway wall, or counterweight where applicable, provided the conductors are grouped together and taped or corded, or in the original sheath. a. NEC® Reference: 620.44(2) b. Answer: 6 © 2024 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part.

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 19: Specific Equipment

18. Information technology equipment shall be permitted to be connected to a branch circuit by a power-supply cord; the power-supply cord shall not exceed __________________ ft. a. NEC® Reference: 645.5(B)(1)) b. Answer: 15 19. Hydromassage bathtub electrical equipment shall be __________________ without damaging the building structure or building finish. a. NEC® Reference: 680.73 b. Answer: accessible 20. All receptacles rated 125 volts through 250 volts, 60 amperes or less, located within __________________ ft of the inside wall of a pool shall have GFCI or SPGFCI protection. a. NEC® Reference: 680.22(A)(4) b. Answer: 20 21. Manufactured wiring systems cable shall be listed Type AC cable or listed Type MC cable containing nominal 600-volt, __________________ AWG insulated copper or copperclad aluminum conductors. a. NEC® Reference: 604.100(A)(1) b. Answer: 8 to 12 22. Luminaires mounted in permanently installed swimming pool walls shall be installed with the top of the luminaire lens at least __________________ in. below the normal water level of the pool, unless the luminaire is listed and identified for use at lesser depths. a. NEC® Reference: 680.23(A)(5) b. Answer: 18 23. Sign or outline lighting system equipment shall be at least __________________ ft above areas accessible to vehicles unless protected from physical damage. a. NEC® Reference: 600.9(A) b. Answer: 14 24. Existing luminaires and lighting outlets located less than __________________ ft measured horizontally from the inside walls of a pool shall be at least _________________ ft above the surface of the maximum water level, shall be rigidly attached to the existing structure, and shall be protected by a ground-fault circuit interrupter. a. NEC® Reference: 680.22(B)(3) b. Answer: 5, 5

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 19: Specific Equipment

25. A fixed or stationary electric sign installed within a fountain shall be at least _________________ ft inside the fountain measured from the outside edges of the fountain. a. NEC® Reference: 680.57(C)(1) b. Answer: 5 26. The conductors to an elevator hoistway door interlock from the hoistway riser shall be flame retardant and suitable for a temperature of not less than _________________. a. NEC® Reference: 620.11(A) and (A)(1) b. Answer: 200°C (or 392°F) 27. In new outdoor pool areas, ceiling-suspended (paddle) fans shall not be installed above the pool or over the area extending _________________ ft horizontally from the inside walls of the pool unless the fan is installed at least _________________ ft above the maximum water level. a. NEC® Reference: 680.22(B)(1) b. Answer: 5, 12 28. The branch-circuit conductors supplying one or more units of information technology equipment shall have an ampacity not less than _________________ of the total connected load. a. NEC® Reference: 645.5(A) b. Answer: 125% 29. A junction box connected to a conduit that extends directly to a forming shell of a noniche luminaire in a permanently installed swimming pool shall be provided with a number of grounding terminals that shall be_________________. a. NEC® Reference: 680.24(D) b. Answer: no fewer than one more than the number of conduit entries 30. A(n) _________________ is a device external to the electric vehicle that transfers power via the contactless coupling as part of a wireless power transfer system. a. NEC® Reference: Article 100 (Primary Pad) b. Answer: primary pad 31. Branch circuits that supply neon tubing installations shall not be rated in excess of _________________. a. NEC® Reference: 600.5(C)(1) b. Answer: 30 amperes

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 19: Specific Equipment

32. The termination of the 8 AWG bonding jumper in a permanently installed swimming pool forming shell shall be covered with or encapsulated in a(n) _________________ to protect the connection from the possible deteriorating effect of pool water. a. NEC® Reference: 680.23(B)(2)(b) b. Answer: listed potting compound 33. Conductors supplying a fire pump motor(s), pressure maintenance pumps, and associated fire pump accessory equipment shall have a rating not less than _________________ of the sum of the fire pump motor(s) and pressure maintenance motor(s) full-load current(s), and _________________ of the associated fire pump accessory equipment full-load current(s). a. NEC® Reference: 695.6(B)(1) b. Answer: 125%, 100% 34. Switching devices shall be located at least _________________ ft horizontally from the inside walls of a pool unless separated from the pool by a solid fence, wall, or other permanent barrier that provides at least a _________________ ft reach distance. a. NEC® Reference: 680.22(C) b. Answer: 5, 5 35. Article _________________ covers electrical equipment, lighting accessories, and wiring systems used to connect, contained within, or installed on office furnishings. a. NEC® Reference: 605.1(A) b. Answer: 605 36. A junction box connected to a conduit that extends directly to a forming shell for an underwater luminaire in a permanently installed swimming pool shall be located not less than _________________ in., measured from the inside of the bottom of the box, above the ground level, or pool deck, or not less than _________________ in. above the maximum pool water level, whichever provides the greater elevation if operating above the low-voltage contact limit. a. NEC® Reference: 680.24(A)(2)(a) b. Answer: 4, 8 in.

37. Vertical runs of wireways, used in elevator installations, shall be securely supported at intervals not exceeding _________________ ft and shall have not more than one joint between supports. a. NEC® Reference: 620.32 b. Answer: 15

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Unit 19: Specific Equipment

38. Where receptacles are used as a means of connecting sensitive electronic equipment, a 125-volt, single-phase, 15- or 20-ampere-rated receptacle having one of its currentcarrying poles connected to a grounded circuit conductor shall be located within_________________ ft of all permanently installed 15- or 20-ampere-rated 60/120-volt technical power-system receptacles. a. NEC® Reference: 647.7(A)(3) b. Answer: 6

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Final Exam 1

Solution and Answer Guide

MILLER/SANDEFUR, ILLUSTRATED GUIDE TO THE NEC®, 21E, ©2024, 9780357766712; FINAL EXAM 1

TABLE OF CONTENTS Final Exam 1........................................................................................................................................................ 1

FINAL EXAM 1 1. No handhole shall be required in a metal pole, supporting a luminaire, that is __________________ ft or less in height above grade that is provided with a hinged base. a. NEC® Reference: 410.30(B)(1) Exception No. 2 b. Answer: 20 2. Where run across the top of framing members, or across the face of rafters or studding, within __________________ ft of the floor or horizontal surface, in an attic that has permanent stairs, nonmetallic-sheathed cable shall be protected by substantial guard strips that are at least as high as the cable. a. NEC® Reference: 320.23(A) b. Answer: 7. Section 334.23 states that nonmetallic-sheathed cable installed in attics must comply with 320.23.

3. Mandatory NEC rules are those that identify actions that are specifically required or prohibited and are characterized by the use of the terms __________________. a. NEC® Reference: 90.5(A) b. Answer: shall or shall not 4. In other than dwelling units, in addition to other arcflash hazard warning requirements in this section, a permanent label shall be field or factory applied to service equipment rated __________________ amps or more. a. NEC® Reference: 110.16(B) b. Answer: 1000 5. A location temporarily subject to dampness or wetness, as in the case of a building under construction, is classified as a(n) __________________ location. a. NEC® Reference: Article 100 (Location, Dry) b. Answer: dry

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Final Exam 1

6. Kitchen countertop receptacle outlets in dwelling units shall be installed so that no point along the wall line is more __________________ than in., measured horizontally from a receptacle outlet in that space. a. NEC® Reference: 210.52(C)(1) b. Answer: 24 7. In hazardous (classified) locations, NPT threaded entries into explosionproof equipment shall be made up with at least __________________ threads fully engaged. a. NEC® Reference: 500.8(E)(1) b. Answer: 5 8. The disconnecting means for motor circuits rated 1000 volts, nominal, or less, shall have an ampacity rating of at least __________________ of the full-load current rating of the motor. a. NEC® Reference: 430.110(A) b. Answer: 115% 9. The life safety and critical branches of a hospital essential electrical system shall be installed and connected to the alternate power source specified in 517.41(A) and (B) so that all specified functions for the life safety and critical branches are automatically restored to operation within __________________ after interruption of the normal source. a. NEC® Reference: 517.32(B) b. Answer: 10 seconds 10. Where an equipment bonding jumper is installed on the outside of a raceway, the length shall not exceed __________________ ft and shall be routed with the raceway or enclosure. a. NEC® Reference: 250.102(E)(2) b. Answer: 6 11. A surface-mounted incandescent or LED luminaire installed on the ceiling of a clothes closet must have a minimum clearance of __________________ in. between the luminaire and the nearest point of the clothes closet storage space. a. NEC® Reference: 410.16(D)(1) b. Answer: 12

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Final Exam 1

12. Where cable trays support individual conductors or multiconductor cables and where the conductors or multiconductor cables pass from one cable tray to another, or from a cable tray to raceway(s) or from a cable tray to equipment where the conductors are terminated, the distance between the cable trays or between the cable tray or between the cable tray and the raceway(s) or the equipment shall not exceed __________________ ft. a. NEC® Reference: 392.30(B)(3) b. Answer: 6 13. In dwelling units, hallways of __________________ ft or more in length shall have at least one receptacle outlet. a. NEC® Reference: 210.52(H) b. Answer: 10 14. A bathroom is an area that includes: I. a tub and a toilet.

II. a sink and a toilet.

III. a toilet and a shower. a) I only b) II only c) either I or III d) I, II, and III a. NEC® Reference: Article 100 (Bathroom) b. Answer: b) II only 15. An outdoor motor fuel dispensing device is considered to be a Class I, Division 2 location up to __________________ in. above grade level within __________________ ft horizontally in all directions from the dispenser enclosure. a. NEC® Reference: Table 514.3(B)(1) b. Answer: 18, 20 16. Where nonmetallic-sheathed cable is run at angles with joists in unfinished basements and crawl spaces, it shall be permissible to secure cables not smaller than two __________________ conductors directly to the lower edges of the joists. a. NEC® Reference: 334.15(C) b. Answer: 6 AWG 17. The ampacity of the supply conductors for a resistance welder that be operated at different times at different values of primary current or duty cycle shall not be less than __________________ of the rated primary current for seam and automatically fed welders. a. NEC® Reference: 630.31(A)(1) b. Answer: 70%

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Final Exam 1

18. Service conductors installed as open conductors shall have a clearance of not less than __________________ ft from windows that are designed to be opened. a. NEC® Reference: 230.9(A) b. Answer: 3 19. The __________________ is the connection between the grounded circuit conductor and the equipment grounding conductor, or the supply-side bonding jumper, or both at the service. a. NEC® Reference: Article 100 (Bonding Jumper, Main) b. Answer: main bonding jumper 20. For installations within or behind a surface of noncombustible material, boxes shall be made so that the front edge of the box will not be set back of the finished surface more than __________________ in. a. NEC® Reference: 314.20 b. Answer: ¼ 21. Each Category 2 space patient bed location in a health care facility be provided with a minimum of __________________ receptacle(s). a. NEC® Reference: 517.18(B)(1) b. Answer: 8 22. Plug fuses of __________________ and __________________ rating shall be identified by a hexagonal configuration of the window, cap, or other prominent part to distinguish them from fuses of higher ampere ratings. a. NEC® Reference: 240.50(C) b. Answer: 15-ampere, lower 23. Branch-circuits that supply neon tubing installations shall not be rated in excess of __________________. a. NEC® Reference: 600.5(C)(1) b. Answer: 30 amperes 24. The width of the working of space in front of electrical equipment, operating at 1000 volts or less, shall be __________________ or 30 in., whichever is greater. a. NEC® Reference: 110.26(A)(2) b. Answer: the width of the equipment

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Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Final Exam 1

25. For each major repair garage floor, the entire area up to a level of __________________ in. above the floor shall be classified as Class I, Division 2 if ventilation is not provided. a. NEC® Reference: Table 511.3(C) b. Answer: 18 26. One 15-ampere-rated duplex receptacle may be installed on a __________________ ampere branch-circuit. a. NEC® Reference: Table 210.21(B)(3) b. Answer: 15 or 20 27. __________________ is defined as connected to establish electrical continuity and conductivity. a. NEC® Reference: Article 100 (Bonded) b. Answer: Bonded or Bonding 28. In dormitory units, all nonlocking-type 125- and 250- volt, 15- and 20-ampere receptacles shall be __________________. a. NEC® Reference: 406.12 b. Answer: listed tamper-resistant receptacles 29. If it is unlikely that two or more __________________ loads will be in use simultaneously, it shall be permissible to use only the largest load(s) that will be used at one time for calculating the total load of a feeder or service. a. NEC® Reference: 220.60 b. Answer: noncoincident 30. Branch-circuit conductors that supply a single motor used in a continuous duty application shall have an ampacity of not less than __________________ of the motor’s full-load current rating as determined by 430.6(A)(1). a. NEC® Reference: 430.22 b. Answer: 125% 31. A clearly labeled emergency shutoff or control switch for the purpose of stopping the motor(s) that provide power to the recirculation system and jet system shall be installed at a point readily accessible to the users and at least __________________ ft away, adjacent to, and within sight of the spa or hot tub for other than one-family dewllings. a. NEC® Reference: 680.41(A) b. Answer: 5

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5

Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Final Exam 1

32. Where __________________ are installed in a box, each section shall be considered as a separate box. a. NEC® Reference: 314.28(D) b. Answer: permanent barriers 33. In a location where flammable anesthetics are employed, the entire area shall be considered to be a Class I, Division I location that shall extend upward to a level __________________ ft above the floor. a. NEC® Reference: 517.60(A)(1) b. Answer: 5 34. Service conductors shall be considered outside of a building or other structure where installed under not less than __________________ in. of concrete beneath a building or other structure. a. NEC® Reference: 230.6 b. Answer: 2 35. A compartment or chamber to which one or more air ducts are connected and that forms part of the air distribution system is a(n) __________________. a. NEC® Reference: Article 100 (Plenum) b. Answer: plenum 36. All cables installed in agricultural buildings shall be secured within __________________ in. of each cabinet, box, or fitting. a. NEC® Reference: 547.21 b. Answer: 8 37. Where field-installed wiring pass through an opening in an enclosure, conduit box, or barrier, a __________________ shall be used to protect the conductors from the edges of an opening having sharp edges within generators. a. NEC® Reference: 445.16 b. Answer: bushing 38. The service equipment shall be mounted in a readily accessible outdoor location, and __________________ from the mobile home it serves. a. NEC® Reference: 550.32(A) b. Answer: within sight

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6

Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Final Exam 1

39. Any dwelling unit wall space __________________ ft or more in width (including space measured around corners) and unbroken along the floor line by doorways and similar openings, fireplaces, stationary appliances, and fixed cabinets that do not have countertops or similar work surfaces shall have a receptacle outlet. a. NEC® Reference: 210.52(A)(2)(1) b. Answer: 2 40. Busways shall be securely supported at intervals not exceeding __________________ ft unless otherwise designed and marked. a. NEC® Reference: 368.30 b. Answer: 5 41. All exposed lamps in theater dressing or makeup areas including rooms where they are less than __________________ ft from the floor, shall be equipped with openend guards riveted to the outlet box cover or otherwise sealed or locked in place. a. NEC® Reference: 520.72 b. Answer: 8 42. When calculating track lighting loads for a commercial service, an additional load of __________________ volt-amperes shall be included for every __________________ ft of lighting track or fraction thereof. a. NEC® Reference: 220.46(B) b. Answer: 150, 2 43. In aircraft maintenance and storage hangars, the area within __________________ ft horizontally from aircraft power plants or aircraft fuel tanks shall be classified as a Class I, Division 2 or Zone 2 location that shall extend upward from the floor to a level __________________ ft above the upper surface of wings and engine enclosures. a. NEC® Reference: 513.3(C)(1) b. Answer: 5, 5 44. The walls and roofs of transformer vaults shall be constructed of materials that have approved structural strength for the conditions with a minimum fire resistance of __________________. a. NEC® Reference: 450.42 b. Answer: 3 hours

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7

Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Final Exam 1

45. Exposed vertical risers from industrial machinery shall be permitted to be supported at intervals not exceeding __________________ ft, provided the intermediate metal conduit is made up with threaded couplings, is securely supported at the top and bottom of the riser, and no other means of intermediate support is readily available. a. NEC® Reference: 342.30(B)(3) b. Answer: 20 46. Duty on elevator driving machine motors shall be rated as __________________. a. NEC® Reference: 620.61(B)(1) b. Answer: intermittent 47. Continuous duty is an operation at a substantially constant load for __________________. a. NEC® Reference: Article 100 (Duty, Continuous) b. Answer: an indefinitely long time 48. Each Category I space patient bed location in a health care facility shall supplied be by at least __________________ branch circuit(s). a. NEC® Reference: 517.19(A) b. Answer: 2 49. A metal pole, supporting a luminaire, does not require a handhole if the pole is __________________ ft or less in height above grade where the supply wiring method continues without splice or pull point, and where the interior of the pole and any splices are accessible by removing the luminaire. a. NEC® Reference: 410.30(B)(1) Exception No. 1 b. Answer: 8 50. For a one-family dwelling, at least one receptacle outlet readily accessible from grade and located not more than __________________ ft above grade level shall be installed at the front and back of the dwelling. a. NEC® Reference: 210.52(E)(1) b. Answer: 6½

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8

Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Final Exam 2

Solution and Answer Guide

MILLER/SANDEFUR, ILLUSTRATED GUIDE TO THE NEC®, 21E, ©2024, 9780357766712; FINAL EXAM 2

TABLE OF CONTENTS Final Exam 2........................................................................................................................................................ 1

FINAL EXAM 2 1. Equipment that is visible and not more than __________________ distant from other equipment is __________________ that other equipment. a. NEC® Reference: Article 100 (In Sight From) b. Answer: 50, in sight from 2. Each operating room in a health care facility shall be provided with a minimum of __________________ receptacles. a. NEC® Reference: 517.19(C)(1) b. Answer: 36 3. Electrical nonmetallic tubing shall not have more than the equivalent of four __________________ bends between pull points. a. NEC® Reference: 362.24(B). b. Answer: quarter, ¼, or 90° 4. In each conduit run leaving a Class I, Division 2 location, the sealing fitting shall be permitted to be installed on either side of the boundary within __________________ ft of the boundary. a. NEC® Reference: 501.15(B)(2) b. Answer: 10 5. The point of attachment of the overhead service conductors to a building shall not be less than above __________________ ft finish grade. a. NEC® Reference: 230.26 b. Answer: 10

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1

Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Final Exam 2

6. Nonmetallic-sheathed cable must be secured within __________________ in. from a single gang plastic device box (2¼ in. x 4 in.) mounted in a wall if the cable is not secured to the box. a. NEC® Reference: 314.17(B)(2) Exception b. Answer: 8 7. The space equal to the width and depth of switchboards, panelboards, and motor control centers and extending from the floor to a height of __________________ ft above the equipment or to the structural ceiling, whichever is lower, shall be dedicated to the electrical installation. a. NEC® Reference: 110.26(E)(1)(a) b. Answer: 6 8. On a 4-wire, delta-connected system where the midpoint of one phase winding is grounded, only the conductor or busbar having the higher phase voltage to ground shall be durably and permanently marked by an outer finish that is __________________ in color or by other effective means. a. NEC® Reference: 110.15 b. Answer: orange 9. A(n) __________________ is a conductor that ensures the required electrical conductivity between metal parts that are required to be electrically connected. a. NEC® Reference: Article 100 (Bonding Conductor) b. Answer: bonding conductor 10. For dwelling units, in each attached garage and in each detached garage with electric power, at least one receptacle outlet shall be installed in each vehicle more than __________________ ft above the floor. a. NEC® Reference: 210.52(G)(1) b. Answer: 5 ½ 11. The total rating of utilization equipment fastened in place, other than luminaires, shall not exceed __________________ percent of the branch-circuit ampere rating where lighting units, cord- and plug-connected utilization equipment not fastened in place, or both, are also supplied. a. NEC® Reference: 210.23(B)(2) b. Answer: 50

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2

Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Final Exam 2

12. A surface-mounted fluorescent luminaire installed on the ceiling of a clothes closet must have a minimum clearance of __________________ in between the luminaire and the nearest point of the closet storage space. a. NEC® Reference: 410.16(D)(2) b. Answer: 6 13. A grounded circuit conductor shall be permitted to be connected non-current-carrying metal parts of equipment on the __________________ side of the ac service to disconnecting means. a. NEC® Reference: 250.142(A) b. Answer: supply 14. Where a permanently installed swimming pool is installed, at least one 125-volt 15- or 20-ampere receptacle on a general-purpose branch circuit shall be located a minimum of __________________ ft from and not more than __________________ from the inside wall of the pool. a. NEC® Reference: 680.22(A)(1) b. Answer: 6, 20 15. In multiwire branch circuits, the continuity of a(n) __________________ shall not depend on device connections such as lampholders, receptacles, and so forth, where the removal of such devices would interrupt the continuity. a. NEC® Reference: 300.13(B) b. Answer: grounded conductor 16. The NEC is not intended as a design specification or a(n) __________________. a. NEC® Reference: 90.2(A) b. Answer: instruction manual for untrained persons 17. A(n) __________________ is a device intended to provide protection from the effects of arc faults by recognizing characteristics unique to arcing and by functioning to de-energize the circuit when an arc fault is detected. a. NEC® Reference: Article 100 (Arc-Fault Circuit Interrupter) b. Answer: Arc-Fault Circuit Interrupter

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3

Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Final Exam 2

18. Panelboards shall be durably marked by the manufacturer with __________________ and the number of ac phases or dc buses for which they are designed and with the manufacturer’s name or trademark in such a manner so as to be visible after installation, without disturbing the interior parts or wiring. a. NEC® Reference: 408.58 b. Answer: the voltage and the current rating 19. Service-entrance cables shall be supported by straps or other approved means within 12 in. of every service head, gooseneck, or connection to a raceway or enclosure and at intervals not exceeding __________________ in. a. NEC® Reference: 230.51(A) b. Answer: 30 20. The ampacity of capacitor circuit conductors shall not be less than __________________ of the rated current of the capacitor, if rated 1000 volts or less. a. NEC® Reference: 460.8(A) b. Answer: 135% 21. A(n) __________________ is defined as the connection between the grounded circuit conductor and the supply-side bonding jumper, or the equipment grounding conductor, or both, at a separately derived system. a. NEC® Reference: Article 100 (Bonding Jumper, System) b. Answer: System bonding jumper 22. If the vertical rise is greater than __________________ ft, 250 kcmil copper conductors in vertical raceways shall be supported a. NEC® Reference: Table 300.19(A) b. Answer: 60 23. Each patient bed location in a Category 1 space of a health care facility shall be provided with a minimum of __________________ receptacle(s). a. NEC® Reference: 517.19(B)(1) b. Answer: 14 24. For dewlling units, a receptacle outlet shall be installed at each kitchen countertop space that is __________________ in. or wider a. NEC® Reference: 210.52(C) b. Answer: 12

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4

Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Final Exam 2

25. Covers of outlet boxes and conduit bodies having holes through which flexible cord pendants may pass shall be provided with approved __________________ or shall have smooth, well-rounded surfaces on which the cord will bear. a. NEC® Reference: 314.102 b. Answer: bushings 26. Internal parts of electrical equipment, including busbars, wiring terminals, insulators, and other surfaces, shall not be __________________ by foreign materials such as paint, plaster, cleaners, abrasives, or corrosive residues. a. NEC® Reference: 110.12(B) b. Answer: damaged or contaminated 27. Interior metal water piping that is electrically continuous with a metal underground water pipe electrode and is located not more than __________________ ft from the point of entrance to the building, as measured along the water piping, shall be permitted to extend the connection to the grounding electrode(s). a. NEC® Reference: 250.68(C)(1) b. Answer: 5 28. In commercial garages, lamps and lampholders for fixed lighting that is located over lanes through which vehicles are commonly driven shall be located not less than __________________ ft above the floor level. a. NEC® Reference: 511.7(B)(1)(b) b. Answer: 12 29. Circuit conductors between the final overcurrent device protecting the circuit and the outlet(s) is called a(n) __________________. a. NEC® Reference: Article 100 (Branch-Circuit) b. Answer: branch-circuit 30. In any anesthetizing area of a health care facility, all metal raceways and metal-sheathed cables, and all normally non-current-carrying conductive portions of fixed electric equipment, shall be __________________. a. NEC® Reference: 517.62 b. Answer: connected to an equipment grounding conductor

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5

Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Final Exam 2

31. A single piece of equipment consisting of a multiple receptacle comprised of four or more receptacles shall be calculated at not less than __________________ per receptacle. a. NEC® Reference: 220.14(I) b. Answer: 90 volt-amperes 32. All fixed metal parts that are within __________________ ft horizontally of the inside walls of a permanently installed swimming pool, and within __________________ ft above the pool’s maximum water level shall be bonded together. a. NEC® Reference: 680.26(B)(7) b. Answer: 5, 12 33. In both exposed and concealed locations, where a cable- or raceway-type wiring method is installed through bored holes in joists, rafters, or wood members, holes shall be bored so that the edge of the hole is not less than __________________ in. from the edges of the wood member. a. NEC® Reference: 300.4(A)(1) b. Answer: 1¼ 34. Receptacle outlets installed in a dwelling unit for specific appliances, such as laundry equipment, shall be installed within __________________ ft of the intended location of the appliance. a. NEC® Reference: 210.50(C) b. Answer: 6 35. Outdoor mobile home disconnecting means shall be installed so the center of the grip of the operating handle, when in the highest position, is not more than __________________ ft __________________ in. above the finished grade or working platform. a. NEC® Reference: 550.32(F) b. Answer: 6, 7 36. Circuit breakers shall be marked with their ampere rating in a manner that will be __________________ after installation. a. NEC® Reference: durable and visible b. Answer: 240.83(A) 37. A door sill or curb that is of an approved height that will confine the oil from the largest transformer within a transformer vault shall be provided, and in no case shall the height be less than __________________ in. a. NEC® Reference: 450.43(B) b. Answer: 4

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6

Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Final Exam 2

38. Sign or outline lighting system equipment shall be at least __________________ ft above areas accessible to vehicles unless protected from physical damage. a. NEC® Reference: 600.9(A) b. Answer: 14 39. A continuous load is where the maximum current is expected to continue for __________________. a. NEC® Reference: Article 100 (Continuous Load) b. Answer: 3 hours or more 40. At least one receptacle outlet shall be located on a wall or partition that is __________________ to the sink or sink countertop, located on the countertop, or installed on the side or face of the sink cabinet in a dwelling unit bathroom. a. NEC® Reference: 210.52(D) b. Answer: adjacent 41. At a carnival, a means to disconnect each portable structure from all ungrounded conductors shall be provided, and the disconnecting means shall be located within sight of and within __________________ ft of the operator’s station. a. NEC® Reference: 525.21(A) b. Answer: 6 42. Ground-fault protection of equipment shall be provided for solidly grounded wye electric services of more than 150 volts to ground, but not exceeding 1000 volts phase-to-phase for each service disconnect rated __________________ or more. a. NEC® Reference: 230.95 b. Answer: 1000 amperes 43. Flexible cords shall be secured to the undersides of showcases so that a separation between cases not in excess of __________________ in., or more than __________________ in. between the first case and the supply receptacle, will be ensured. a. NEC® Reference: 410.59(C) b. Answer: 2, 12 44. A(n) __________________ is a structure designed to support a wetniche luminaire assembly and intended for mounting in a pool or fountain structure. a. NEC® Reference: Article 100 (Forming Shell) b. Answer: forming shell

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7

Solution and Answer Guide: Miller/Sandefur, Illustrated Guide to the NEC®, ©2024, 9780357766712, Final Exam 2

45. If multiple ground rods are installed for the grounding electrode system, they shall not be less than __________________ ft apart. a. NEC® Reference: 250.53(A)(3) b. Answer: 6 46. Generally, receptacles in dwelling units shall be so installed so that no point measured horizontally along the floor line of any wall space is more than __________________ ft from a receptacle outlet. a. NEC® Reference: 210.52(A)(1) b. Answer: 6 47. Shore power for boats shall be provided by single receptacles rated not less than __________________ amperes. a. NEC® Reference: 555.33(A)(4) b. Answer: 30 48. Aircraft energizers shall be designed and mounted such that all electric equipment and fixed wiring will be at least __________________ in. above floor level. a. NEC® Reference: 513.10(C)(1) b. Answer: 18 49. Unless otherwise permitted, Type AC cable shall be supported and secured at intervals not exceeding __________________ ft. a. NEC® Reference: 320.30(B) and (C) b. Answer: 4½ 50. The life safety branch and equipment branches in a hospital shall be installed and connected to the alternate source of power so that all specified functions for the life safety and equipment branches are automatically restored to operation within __________________ seconds after the interruption of the normal source. a. NEC® Reference: 517.43 b. Answer: 10

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8

Instructor’s Guide to Accompany the

Illustrated Guide ® to the NEC , 9e Charles R. Miller

Australia • Brazil • Japan • Korea • Mexico • Singapore • Spain • United Kingdom • United States

CONTENTS To the Instructor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . v

SECTION 1

FOUNDATIONAL PROVISIONS

UNIT 1

INTRODUCTION TO THE NATIONAL ELECTRICAL CODE ® . . . . . . . . . . . . . . . . . . . . . . . . . . 1

UNIT 2

DEFINITIONS Competency Test Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

UNIT 3

BOXES AND ENCLOSURES Competency Test Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

UNIT 4

CABLES Competency Test Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

UNIT 5

RACEWAYS AND CONDUCTORS Competency Test Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

SECTION 2

ONE-FAMILY DWELLINGS

UNIT 6

GENERAL PROVISIONS Competency Test Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

UNIT 7

SPECIFIC PROVISIONS Competency Test Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

UNIT 8

LOAD CALCULATIONS Competency Test Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

UNIT 9

SERVICES AND ELECTRICAL EQUIPMENT Competency Test Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

SECTION 3

MULTIFAMILY DWELLINGS

UNIT 10

COMPREHENSIVE PROVISIONS Competency Test Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

UNIT 11

LOAD CALCULATIONS Competency Test Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

ii

SECTION 4

COMMERCIAL LOCATIONS

UNIT 12

GENERAL PROVISIONS Competency Test Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

UNIT 13

NONDWELLING LOAD CALCULATIONS Competency Test Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

UNIT 14

SERVICES, FEEDERS, AND EQUIPMENT Competency Test Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

SECTION 5

SPECIAL OCCUPANCIES, AREAS, AND EQUIPMENT

UNIT 15

HAZARDOUS (CLASSIFIED) LOCATIONS Competency Test Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

UNIT 16

HEALTH CARE Competency Test Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

UNIT 17

INDUSTRIAL LOCATIONS Competency Test Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

UNIT 18

SPECIAL OCCUPANCIES Competency Test Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

UNIT 19

SPECIFIC EQUIPMENT Competency Test Answers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

FINAL EXAM 1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 FINAL EXAM 1 ANSWERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 FINAL EXAM 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 FINAL EXAM 2

ANSWERS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

iii

TO THE INSTRUCTOR Illustrated Guide to the NEC ®, 9e is an exciting new tool for those who teach the National Electrical Code. This text represents a dramatic blend of new presentation styles with tried-and-true instructional practices. Symbolizing a revolutionary breakthrough in teaching material, the text communicates with the reader primarily through visualization. If a picture is truly worth a thousand words, this book is a virtual encyclopedia on the National Electrical Code. While technically accurate and highly detailed illustrations tell a story all their own, they are further enhanced through clearly written, concise blocks of text that can be read very quickly and understood with ease.

Not only is the presentation method exceptional but also the organization of material is unique. After covering fundamental provisions in Section 1, Illustrated Guide to the NEC proceeds to address code requirements according to the type of occupancy. Comprehensive information is given for one-family dwellings, multifamily dwellings, commercial locations, and special occupancies. Information found scattered throughout the Code book has been logically gathered and concentrated under the appropriate occupancy. All relevant aspects are thoroughly discussed and illustrated accordingly.

As a teaching tool, this text stands alone, unlike any previously offered. Rest assured, however, that proven training methods have not been sacrificed for the sake of being different. Unit objectives still introduce new ideas to the reader, summaries review the material after presentation, and competency tests reinforce what has been learned.

As a valuable resource to the instructor, this Instructor’s Guide provides unit competency test question answers and explanations, and two fifty-question comprehensive final exams, which can be given independently or as a single test. Unequaled as a teaching tool, Illustrated Guide to the NEC strives to make the entire process easier and more enjoyable.

From beginners to master electricians, this text has something for everyone practicing a trade in the electrical industry. The variety of teaching styles facilitated by Illustrated Guide to the National Electrical Code is essentially limitless. Whether the instructor focuses on a specific area of application or wants to teach the Code from cover to cover, Illustrated Guide to the NEC offers a visually pleasing format that holds student interest and awakens comprehension. Intended not as a replacement, but as an indispensable supplement to the National Electrical Code, the text translates the sometimes vague, often rambling, language of the Code into clearer, cleaner, simpler terms. Once the instructor has communicated these concepts so that the student understands how the Code translates in a particular area, the same techniques can be applied throughout this course of study.

As the title implies, frequent references are made to the National Electrical Code. Have each student keep a copy of the current edition close at hand. On countless occasions, the Code provides the definitive source of information. Should, for example, any confusion about terminology exist that is not cleared up by the Definitions section (Unit 2), consulting the Code’s Article 100 — Definitions section may well offer the needed clarification.

Whenever direct references are made to the Code, the class will benefit by taking the time to read the suggested article or section.

The true success of any teaching endeavor rests in the hands of the instructor. No matter how good the material, it is ultimately the instructor who enriches the mind of each and every student. It is the intention of the author and Cengage to lighten this imposing responsibility by placing exceptional resources at the instructor’s disposal.

iv

Section 1

FOUNDATIONAL PROVISIONS

UNIT 1 COMPETENCY TEST 1. Answer: Reference:

1911 NEC page 1

2. Answer: Reference:

A Informative Annex A

3. Answer: Reference:

Chapters 1, 2, 3, and 4 90.3

4. Answer: Reference:

1975 NEC page 1

5. Answer: Reference:

persons and property 90.2(A)

6. Answer: Reference:

1897 NEC page 1

7. Answer: Reference:

informational purposes 90.3

8. Answer: Reference:

New York City page 2

9. Answer: Reference:

9 90.3

10. Answer: Reference:

Underwriters Laboratories Annex I, footnote under Table I.3

11. Answer: Reference:

instructions 110.3(B)

1

UNIT 2 COMPETENCY TEST 1. Answer: general purpose Reference: Article 100 (Branch-Circuit, General Purpose) 2. Answer: Available fault current Reference: Article 100 (Fault Current, Available) 3. Answer: multiwire Reference: Article 100 (Branch-Circuit, Multiwire) periodic duty 4. Answer: Reference: Article 100 (Duty, Periodic) 5. Answer: main bonding jumper Reference: Article 100 (Bonding Jumper, Main) grounding electrode conductor 6. Answer: Reference: Article 100 (Grounding Electrode Conductor) 7. Answer: weatherproof Reference: Article 100 (Weatherproof: Informational Note) 8. Answer: effective ground-fault current path Reference: Article 100 (Ground Fault Current Path, Effective) bypass isolation transfer switch 9. Answer: Reference: Article 100 (Transfer Switch, Bypass Isolation) 10. Answer: multioutlet assembly Reference: Article 100 (Multioutlet Assembly) 11. Answer: wet Reference: Article 100 (Location, Wet) 12. Answer: thermal protector Reference: Article 100 (Thermal Protector: Informational Note) 13. Answer: cabinet Reference: Article 100 (Cabinet) 14. Answer: hoistway Reference: Article 100 (Hoistway) 15. Answer: c) both I and II Reference: 210.4(C) Exceptions No. 1 and 2 16. Answer: fuse Reference: Article 100 (Fuse) 17. Answer: Festoon lighting Reference: Article 100 (Festoon Lighting) 2

18. Answer:

One item named must be a sink; the other item can be a toilet, a urinal, a tub, a shower, a bidet, or similar plumbing fixture.

Reference: Article 100 (Bathroom)

19. Answer: c) maximum Reference: Article 100 (Continuous Load) 20. Answer: resistor Reference: Article 100 (Grounded, Solidly) 21. Answer: outlet Reference: Article 100 (Outlet) 22. Answer: branch-circuit Reference: Article 100 (Branch-Circuit) 23. Answer: Raintight Reference: Article 100 (Raintight) 24. Answer: d) an indefinitely long time Reference: Article 100 (Duty, Continuous) 25. Answer: its temperature rating Reference: Article 100 (Ampacity) 26. Answer: 50 Reference: Article 100 (In Sight From [Within Sight From, Within Sight]) 27. Answer: multifamily dwelling Reference: Article 100 (Dwelling, Multifamily) 28. Answer: the earth Reference: Article 100 (Ground) 29. Answer: vectorial sum Reference: Article 100 (Neutral Point: Informational Note) yes 30. Answer: Reference: Article 100 (Accessible, Readily)

separately derived system 31. Answer: Reference: Article 100 (Separately Derived System) branch-circuit 32. Answer: Reference: Article 100 (Feeder) appliance 33. Answer: Reference: Article 100 (Appliance) individual 34. Answer: Reference: Article 100 (Branch Circuit, Motor)

UNIT 3 COMPETENCY TEST 1. Answer:

d) 72; 6 (ft) x 12 (in.) = 72 in.

Reference: 314.28(B)

accessible 2. Answer: Reference: 314.29(A) 3. Answer:

“X” = 24 in., and “Y” = 12 in. The “X” dimension contains both straight and angle pulls. Use the larger of the two.

“X” (straight pull) = 3 x 8 = 24. “X” (angle pull) 3 x 6 + 2 = 20. The “Y” dimension has an angle pull only. “Y” = 2 x 6 = 12.

Reference: 314.28(A)

4. Answer: ½ Reference: 314.24(A) 5. Answer:

8. The total 12 AWG conductors permitted by Table 314.16(A) is 18.

The flat plaster ring does not provide any additional cubic in. capacity. Two receptacles count as 4 [314.16(B)(4)], two internal cable clamps count as 1 [314.16(B)(2)], four 12 AWG THHN copper conductors count as 4 [314.16(B)(1)], and two grounding conductors count as 1 [314.16(B)(5)] 12 AWG conductors. There are 10 existing 12 AWG conductors. Three wirenuts, two pigtails, and one equipment bonding jumper do not count.

Reference: 314.16

6. Answer: ¼ Reference: 312.2 7. Answer: 0.0625 in.

Reference: 314.100(B) 8. Answer: bushings Reference: 314.102

12. Answer: equipment grounding conductor Reference: 314.100(D) 13. Answer: ¼ Reference: 314.20 14. Answer: temperature-rated Reference: 314.17(B)(4) 15. Answer: 0 Reference: 312.2 Exception 16. Answer: 6 Reference: Table 314.16(A) 17. Answer: 8 Reference: 382.30(A) 18. Answer: 4 Reference: 314.28(A)(2) Exception and Table 312.6(A) 19. Answer: individual holes Reference: 314.17(B)(1) 20. Answer: 6 Reference: 314.27(A)(1) Exception 21. Answer: 48 times Reference: 314.71(A) 22. Answer: 1/8 in., 1/4 in.

Reference: 314.15 23. Answer: substantially equivalent Reference: 110.12(A)

24. Answer: 6 inches Reference: 300.14 25. Answer: 4.5, 4 Reference: 314.16(B)(4) and Table 314.16(B)

9. Answer: a) none Reference: 314.23(F) 10. Answer: separate box Reference: 314.28(D) 11. Answer: 4 (6 – 2 = 4) Reference: 314.16(B)(3) and Table 314.16(A)

3

UNIT 4 COMPETENCY TEST 1. Answer: 12 Reference: 334.30 2. Answer: 39.37 Reference: 324.41 3. Answer: 4½ Reference: 320.30(B) and (C) 4. Answer: 35 Reference: Table 326.24 Type MC cable 5. Answer: Reference: Article 100 (Cable, Metal Clad [Type MC]) 6. Answer: moisture Reference: 332.40(B) 7. Answer: c) 8 Reference: 334.15(C) 8. Answer: Type MV cable Reference: Article 100 (Cable, Medium Voltage [Type MV])

18. Answer: c) 90°C Reference: 320.80(A) 19. Answer:

d) 72.

6 (ft) x 12 (in.) = 72 (in.).

Reference: 330.30(B) and (C)

20. Answer: 168 Reference: Table 326.80 21. Answer: b) 12 Reference: Table 300.5(A) 22. Answer: listed bushings, listed grommets Reference: 300.4(B)(1) 1/16 23. Answer: Reference: 300.4(A)(1)

24. Answer: 20, 30 Reference: 324.10(B)(2)

9. Answer: d) I, II, and III Reference: 340.116

25. Answer: 6 Reference: 332.30

10. Answer: transition assembly Reference: 324.40(D)

26. Answer: 18 Reference: Table 300.5(A)

11. Answer: c) 24. (2 ft = 24 in.).

Reference: 320.30(D)(2)

27. Answer: circuit path Reference: 404.2(C) Informational Note

12. Answer: grounded circuit conductor Reference: 404.2(C)

28. Answer:

13. Answer: seven Reference: 330.24(B) 14. Answer: 1¼ Reference: 300.4(A)(1) 15. Answer: 7 ft.

Reference: 334.23 and 320.23(A) 16. Answer: c) I and III only Reference: 324.120(A)

4

Type MI cable 17. Answer: Reference: Article 100 (Cable, Mineral-Insulated, Metal-Sheathed [Type MI])

c) the return conductor from the switch to the outlet Reference: 200.7(C)(1)

29. Answer: substantially increased Reference: 300.21 plenum 30. Answer: Reference: Article 100 (Plenum)

UNIT 5 COMPETENCY TEST 1. Answer:

d) listed or approved for use in wet locations and arranged to drain.

Reference: 230.53

2. Answer: quarter, ¼, or 90° Reference: 344.26 3. Answer: 3.356 Reference: Chapter 9, Table 4 4. Answer: ¾ Reference: 344.28 5. Answer: c) I and II only Reference: 380.12(5) and 380.76 6. Answer: 75% Reference: 376.56(A) 7. Answer: header Reference: Aticle 100 (Header) 8. Answer: 1¼ Reference: 300.4(A)(1) 9. Answer: 4 Reference: Table 348.22 10. Answer: 16 Reference: 342.30(B)(2) and Table 344.30(B)(2) 11. Answer: 20% Reference: 378.22 12. Answer: induction Reference: 300.20(A) 13. Answer: multioutlet assembly Reference: Article 100 (Multioutlet Assembly) 14. Answer: galvanic action Reference: 342.14 15. Answer: 7 Reference: Informative Annex C, Table C9 6 16. Answer: Reference: 314.28(A)(2) 17. Answer: 85 amps Reference: 110.14(C)(1) and Table 310.16 18. Answer: 6 Reference: 250.102(E)(2)

19. Answer: c) I and III only Reference: 372.18(B) 20. Answer: 3 Reference: 362.30(A) 21. Answer: wet Reference: Article 100 (Location, Wet) 22. Answer: b) shall be removed from the raceway.

Reference: 390.57 23. Answer: corrosion protection Reference: 344.10(B)(1) 24. Answer: 8 AWG Reference: 310.3(C) 25. Answer: 180 Reference: Table 300.19(A) 26. Answer: 4 AWG Reference: 300.4(G) 27. Answer: 3 ft Reference: 378.30(A) 28. Answer: 10, 3 Reference: 342.30(B)(4) 29. Answer: 1.496 sq in.

Reference: Chapter 9, Table 4 30. Answer: equipment bonding jumpers Reference: 250.98 31. Answer: 3 Reference: 344.30(A)(1) 32. Answer: 7 Reference: Table 352.30(B) 33. Answer: 0.8 Reference: Chapter 9, Note 7 30° 34. Answer: Reference: 376.23(A) 35. Answer: 60 Reference: 310.15(B)(2) 36. Answer: unobstructed Reference: 376.56(B)(5)

37. Answer: 1/0 AWG Reference: 310.10(G)(1)

5

Section 2

ONE-FAMILY DWELLINGS

UNIT 6 COMPETENCY TEST 1. Answer: b) 20 ampere Reference: Table 210.21(B)(3)

15. Answer: 15 or 20 Reference: Table 210.21(B)(3)

2. Answer: b) multiwire branch-circuits Reference: 300.13(B)

16. Answer: individual Reference: Article 100 (Branch-Circuit, Individual)

3. Answer: 5½ Reference: 210.52

17. Answer: 12 Reference: 210.52(A)(1)

4. Answer: 6 Reference: 300.14 5. Answer:

b) must be the same size as the insulated circuit conductors Reference: Table 250.122

6. Answer: 6 Reference: 210.8(A)(8)

3; Multiply 1800 ft by 3 volt-ampere: 1800 × 3 = 5400 volt-amperes Find the total amperes: 5400 ÷ 120 = 45 amps Divide 45 amps by 15: 45 ÷ 15 = 3 Reference: 220.41

7. Answer:

2

8. Answer: b) 25 amperes Reference: 210.18 9. Answer: listed wall-mounted control device Reference: 210.70(A)(2)(2) 10. Answer: b) I and III only Reference: 406.4(A) 11. Answer: 70 Reference: 314.27(C) 12. Answer: 18 Reference: 210.52(A)(3) 13. Answer: 6 1/2 Reference: 210.52(E)(1) 14. Answer: 50 Reference: 314.27(A)(2)

6

18. Answer: c) II and III only Reference: 406.4(D)(2)(c) 19. Answer: general purpose Reference: Article 100 (Branch Circuit, General-Purpose) 20. Answer: 6 ft 7 in.

Reference: 404.8(A) 21. Answer: d) Hallway Reference: 210.70(A)(1) and (2) 22. Answer: 40 or 50 Reference: Table 210.21(B)(3) 23. Answer: b) bathrooms Reference: 210.12(A) 24. Answer:

c) the circuit conductors between the final overcurrent device protecting the circuit and the outlet(s) Reference: Article 100 (Branch-Circuit)

25. Answer: d) II or III only Reference: 240.15(B) and (B)(1)

UNIT 7 COMPETENCY TEST 1. Answer: 4 Reference: 210.52(C)(1)

18. Answer: readily accessible Reference: 240.10

2. Answer: 8 Reference: 410.10(D)

19. Answer: 6.5 Reference: 422.16(B)(2)(2)

3. Answer: c) 15 or 20 ampere Reference: Table 210.21(B)(3)

20. Answer:

4. Answer: b) 10 AWG Reference: 210.19(C) Exception No. 2 5. Answer: 194 Reference: 410.11 6. Answer: 2 Reference: 210.70(A)(2) 7. Answer: clothes closets Reference: 240.24(D) 8. Answer: b) 100% Reference: 210.21(B)(1) 9. Answer: 6 Reference: 210.50(C) 10. Answer: 20 Reference: 210.19(C) Exception No. 1 11. Answer:

9200; 4 + 5.5 + 5.5 = 15 kW. Increase Column A by 15% (15 – 12 = 3 x 5% = 15%) 8 x 15% = 1.2 kW 8 + 1.2 = 9.2 kW 9.2 x 1000 = 9200 watts.

Reference: Table 220.55, Note 6

12. Answer: 80 Reference: 210.23(B)(1) 13. Answer: 6 Reference: 410.16(D)(3) 14. Answer: 50 Reference: Article 100 (In Sight From) 15. Answer: one Reference: 210.52(H)

b) I and II only. A receptacle in a detached garage is required only if the garage has electrical power.

Reference: 210.52(G)

21. Answer: d) I, II, or III Reference: 210.52(B)(1) and 210.52(B)(1) Exception No. 2 22. Answer: c) II or III Reference: The laundry circuit must be a 20ampere circuit [210.11(C)(2)]. A single receptacle cannot exceed the rating of the circuit. A duplex receptacle rated 15 amperes is permitted on a 20-ampere circuit [Table 210.21(B)(3)].

23. Answer: 3 Reference: 210.52(D) 24. Answer:

Provisions for a future addition of a receptacle outlet must be provided.

Reference: 210.52(C)(2)

25. Answer: b) I or II only Reference: 210.11(C)(3) and 210.11(C)(3) Exception 26. Answer: 20 Reference: 210.11(C)(4) 27. Answer: 22, 30 Reference: 110.26(A)(4)

28. Answer: 2 Reference: 210.11(C)(1) 29. Answer: readily accessible Reference: 210.8 30. Answer: 25 Reference: 210.63

16. Answer: c) I or II only Reference: 422.31(B) 17. Answer: six Reference: 210.70(A)(2)(3)

7

UNIT 8 COMPETENCY TEST 1. Answer: 75, four Reference: 220.53 2. Answer:

7092 volt-amperes. First, find the total floor area of the house. Multiply the dimensions of each floor and add the two: 30 x 48 = 1440 sq ft (first floor); 22 x 42 = 924 sq ft (second floor); 1440 + 924 = 2364 total sq ft.

Next, multiply the total square ft by three (3) volt-amperes per square foot: 2364 x 3 = 7092 volt-amperes.

Reference: 220.5(C) and 220.41 0 VA 3. Answer: Reference: 220.41 4. Answer: 1500 Reference: 220.52(A) 5. Answer:

d) 6.6 kW. The question is asking for the service load, not the branchcircuit load. 3.5 + 3.5 + 5 = 12 kW (for three units). Table 220.55, Column B for three units has a demand factor of 55%. 12 x 55% = 6.6 kW. Reference: Table 220.55 14.58. 5 kVA (5000 VA) is the minimum dryer load. 5000 ÷ 240 = 20.83 (amperes) 20.83 x 70% = 14.58 (neutral amperes).

Reference: 220.54 and 220.61(B)

Table 250.66 requires a 6 AWG copper grounding electrode conductor for 1/0 service-entrance conductors.

Reference: Table 250.66 7314 volt-amperes. Heat = 6 (units) x 3000 (watts) = 18,000; [Four (or more) separately controlled, space heaters have a demand factor of 40%.

(220.30(C)(6)]; 18,000 x 40% = 7200 watts (volt-amperes). A/C = 2 (units) x 10.5 (amperes) x 230 (volts) = 4830 volt-amperes; 3 (units) x 7.2 (amperes) x 115 (volts) = 2484 volt-amperes. Air-conditioning loads have a demand factor of 100% (220.30(C)(1). Total air-conditioning load 4830 + 2484 = 7314 volt-amperes. The air-conditioning load is larger than the heating load.

Reference: 220.82(C)

10. Answer:

11. Answer: 1500 Reference: 220.52(B) 12. Answer: 8000 Reference: Table 220.55 13. Answer:

145 amperes

14. Answer:

150 amperes

15. Answer:

1 AWG copper. In accordance with Table 310.12(A), the minimum size service conductors for a 150-ampere service are 1 AWG copper.

16. Answer:

6 AWG copper

17. Answer:

114 amperes

18. Answer:

125 amperes

19. Answer:

2 AWG copper. In accordance with Table 310.12(A), the minimum size service] conductors for a 125-ampere service are 2 AWG copper.

20. Answer:

8 AWG copper

21. Answer:

4 AWG copper

6. Answer:

7. Answer:

2495 volt-amperes; dishwasher 1 x 1000 = 1000 (single-phase motor current ratings are located in Table 430.148); disposer 5.8 x 115 = 667; compactor 7.2 x 115 = 828; 1000 + 667 + 828 = 2495 volt-amperes.

Note: No demand factors are allowed on three or fewer fastened-in-place appliances.

Reference: 220.53

8. Answer: 100 Reference: 230.79(C) 9. Answer:

8

6 AWG. In accordance with Table 310.12(A), the minimum size service conductors for a 175-ampere service are 1/0 AWG copper.

Standard Method Load Calculation for One-Family Dwellings Unit 8 . . . Questions 13 through 16 1 General Lighting and Receptacle Loads 220.41

2500

1

7500

2

= 2

3000

1

= 3

1500

Do not include open porches, or unfinished areas not adaptable 3 × for future use as a habitable room or occupiable space. (sq ft using outside dimensions) 2 Small-Appliance Branch-Circuits 220.52(A) At least two small-appliance branch circuits 1500 × must be included. 210.11(C)(1) (minimum of two) 3 Laundry Branch Circuit(s) 220.52(B) At least one laundry branch circuit 1500 × must be included. 210.11(C)(2) (minimum of one)

4 Add lines 1, 2, and 3 5

12,000

12,000 9000

4 – 3000 =

5

(line 4)

Lines 5 through 8 utilize the demand factors found in Table 220.45.

----

6

(if 117,000 or less, skip to line 8)

× 25% = 7

7

=

9000

8

(line 6)

× 35% = 8

(smaller of line 5 or 117,000)

9 Total General Lighting and Receptacle Load

3000 +

----

– 117,000 = 6

(line 5, if more than 117,000)

----

+

(line 7)

3/50

3/50

= 9

6/50

1500

disposer

/ / /

(line 8)

10 Fastened-In-Place Appliances 220.53 Rated 1/4 hp or 500 Watts or Greater Use the nameplate rating.

Do not include electric cooking equipment, clothes dryers, spaceheating equipment, or airconditioning equipment.

water heater compactor

/ / /

4000

dishwasher

/ / /

828

× 75% = 10

6328

11 (If present; otherwise skip to line 12.) Use 5000 watts or the nameplate rating, whichever is larger.

The neutral demand load is 70% for services and feeders. 220.61(B) 12 Household Electric Cooking Appliances Over 1750 Watts 220.55 12 (If present; otherwise skip to line 13.) Use Table 220.55 and all of the applicable Notes.

The neutral demand load is 70% for services and feeders. 220.61(B) 13 Heating or Air-Conditioning System (Compare the heat and A/C, and omit the smaller.) 220.60 13 Include the air handler when using either one. For heat pumps, include the compressor and the maximum amount of electric heat that can be energized while the compressor is running.

14 Largest Motor (one motor only) 220.50, 440.32 through .35 and 430.24 through .26.

Multiply the volt-amperes of the largest motor by 25%. × 25% = 14 If 25% of the largest motor is in line 13, leave line 14 blank. (volt-amps of largest motor)

5000

15

34,701

If fewer than four units, put total volt-amperes on line 10.

If four or more units, multiply total volt-amperes by 75%.

(volt-amps of four or more)

11 Electric Clothes Dryers 220.54

15 Total Volt-Ampere Demand Load: Add lines 9 through 14 to find the minimum required volt-amperes.

8000 9223 ----

16 Minimum Amperes

Minimum Size Divide the total 16 17 Service or 17 volt-amperes by ÷ = Feeder 240.6(A) the voltage. (line 15) (voltage) (minimum amperes) 18 Size the Service or Feeder Conductors.

Use Table 310.12(A) to find the service conductors up to 400 amperes.

Minimum Size 18 Ratings in excess of 400 amperes shall comply with Table 310.16.

Conductors Table 310.12(A) also applies to feeder conductors supplying the entire load.

19 Size the Neutral Conductor. 220.61 310.12(D) states that the neutral service or feeder conductor Minimum Size can be smaller than the ungrounded (hot) conductors, provided the 19 Neutral requirements of 215.2, 220.61, and 230.42 are met.

Conductor 250.24(D)(1) states that the grounded conductor shall not be smaller than specified in Table 250.102(C)(1).

20 Size the Grounding Electrode Conductor (for Service). 250.66 Minimum Size Use line 18 to find the grounding electrode conductor in Table 250.66.

Grounding Size the Equipment Grounding Conductor (for Feeder). 250.122 20 Electrode Use line 17 to find the equipment grounding conductor in Table 250.122.

Conductor Equipment grounding conductor types are listed in 250.118.

34,701

240

145

150 1 copper

6 copper

9

Optional Method Load Calculation for One-Family Dwellings Unit 8 . . . Questions 17 through 20 1 General Lighting and Receptacle Loads 220.82(B)(1) 2 3 4

5

2500

1

7500

2

2

3000

1

3

1500

4

22,328

Do not include open porches, garages, or unused or 3× = unfinished spaces not adaptable for future use. (sq ft using outside dimensions) Small-Appliance Branch Circuits 220.82(B)(2) At least two small-appliance branch circuits 1500 × = must be included. 210.11(C)(1) (minimum of two) Laundry Branch Circuit(s) 220.82(B)(2) At least one laundry branch circuit 1500 × = must be included. 210.11(C)(2) (minimum of one) Appliances 220.82(B)(3) and (4) Do not include any heating Total volt-amperes Use the nameplate rating of all or air-conditioning of all appliances appliances (fastened in place, equipment in this section.

LISTED BELOW permanently connected, or water heater / clothes dryer / 4000 4000 connected to a specific circuit), 1500 ranges, ovens, cooktops, motors, dishwasher / disposer / 828 water heaters, and clothes dryers. / / Convert any nameplate rating given in amperes to volt-amperes / / by multiplying the amperes / / by the rated voltage.

Apply 220.82(B) demand factor to the total of lines 1 through 4.

34,328

24,328

– 10,000 =

9731

× 40% =

12,000

range

/ / / / /

5

19,731

+ 10,000 =

(total of lines 1 through 4)

c) Supplemental electric heating equipment for heat-pump systems. Include the

6 Heating or Air-Conditioning System 220.82(C) Use the nameplate ratings in volt-amperes for all applicable systems in lines a through e.

a) Air-conditioning and cooling systems, including heat pumps without any supplemental electric heating:

7613

× 100% =

a)

7613

b) Electric thermal storage and other heating systems, where the usual load is expected to be continuous at full nameplate value. Systems qualifying under this selection shall not be figured under any other selection in 220.82(C). × 100% = 7 Total Volt-Ampere Demand Load:

heat-pump compressor(s) at 100%. If the heat-pump compressor is prevented from operating with the supplemental heat, omit the compressor. c)

6667

× 65% = d) Electric space-heating equipment, if fewer than four separately controlled units: d) × 65% = e) Electric space-heating equipment, if four or more separately controlled units:

b)

× 40% =

7613

19,731

+

(largest VA rating from line 6a through 6e)

27,344 (line 7)

÷

240 = 8

(voltage)

= 7

(line 5)

8 Minimum Amperes Divide the total volt-amperes by the voltage.

4334

114 (minimum amperes)

Minimum Size

9 Service or

9

Feeder 240.6(A)

e)

27,344 125 (minimum is 100 amperes)

10 Size the Service or Feeder Conductors.

Use Table 310.12(A) to find the service conductors up to 400 amperes.

Ratings in excess of 400 amperes shall comply with Table 310.16.

Table 310.12(A) also applies to feeder conductors supplying the entire load.

11 Size the Neutral Conductor. 220.61 Note: There is no optional method for calculating the neutral conductor.

310.12(D) states that the neutral service or feeder conductor can be smaller than the ungrounded (hot) conductors, provided the requirements of 215.2, 220.61, and 230.42 are met.

250.24(D)(1) states that the grounded conductor shall not be smaller than specified in Table 250.102(C)(1).

12 Size the Grounding Electrode Conductor.

Use line 10 to find the grounding electrode conductor in Table 250.66.

Size the Equipment Grounding Conductor (for Feeder). 250.122 Use line 9 to find the equipment grounding conductor in Table 250.122.

Equipment grounding conductor types are listed in 250.118.

10

Minimum Size 10 Conductors

2 copper

Minimum Size 11 Neutral Conductor

Minimum Size Grounding 12 Electrode Conductor

8 copper

Neutral Method Load Calculation for One-Family Dwellings Unit Calculation 8 . . . Question 21 Standard Method Load for One-Family Dwellings 1 General Lighting and Receptacle Loads 220.41 Do not include open porches, or unfinished areas not adaptable for future use as a habitable room or occcupiable space 2 Small-Appliance Branch-Circuits 220.52(A) At least two small-appliance branch circuits must be included. 210.11(C)(1) 3 Laundry Branch Circuit(s) 220.52(B) At least one laundry branch circuit must be included. 210.11(C)(2)

4 Add lines 1, 2, and 3 5

12,000

– 3000 =

5

(line 4)

7

----

12,000 9000

4

9 Total General Lighting and Receptacle Load

7500

2

1500 ×

= 2

3000

= 3

1500

(minimum of two)

1

1500 ×

(minimum of one)

Lines 5 through 8 utilize the demand factors found in Table 220.45.

----

6

----

× 25% = 7

1

=

(sq ft using outside dimensions)

(if 117,000 or less, skip to line 8)

(line 6)

2500

3×

9000

8

× 35% = 8

(smaller of line 5 or 117,000)

3000 +

----

– 117,000 = 6

(line 5, if more than 117,000)

----

+

(line 7)

3150

3150

= 9

6150

1500

disposer

/ / /

(line 8)

10 Fastened-In-Place Appliances 220.53 Rated 1/4 hp or 500 Watts or Greater Use the nameplate rating.

Do not include electric cooking equipment, clothes dryers, space-

compactor

/ / /

-0-

dishwasher

/ / /

828

× 75% = 10

2328

11 (If present; otherwise skip to line 12.) Use 5000 watts or the nameplate rating, whichever is larger.

The neutral demand load is 70% for services and feeders. 220.61(B) 12 Household Eletric Cooking Appliances Over 1750 Watts 220.55 12 (If present; otherwise skip to line 13.) Use Table 220.55 and all of the applicable Notes.

The neutral demand load is 70% for services and feeders. 220.61(B) 13 Heating or Air-Conditioning System (Compare the heat and A/C, and omit the smaller.) 220.60 13 Include the air handler when using either one. For heat pumps, include the compressor and the maximum amount of electric heat that can be energized while the compressor is running.

14 Largest Motor (one motor only) 220.50,440.32 through .35, and 430.24 through .26 Multiply the volt-amperes of the largest motor by 25%. × 25% = 14 (volt-amps of largest motor) If 25% of the largest motor is in line 13, leave line 14 blank.

3500

15

18,958

If fewer than four units, put total volt-amperes on line 10.

If four or more units, multiply total volt-amperes by 75%.

(volt-amps of four or more)

11 Electric Clothes Dryers 220.54

828

15 Total Volt-Ampere Demand Load: Add lines 9 through 14 to find the minimum required volt-amperes.

5600 1173 207

16 Minimum Amperes

Minimum Size Divide the total 16 17 Service or 17 volt-amperes by ÷ = Feeder 240.6(A) the voltage. (line 15) (voltage) (minimum amperes) 18 Size the Service or Feeder Conductors.

Use Table 310.12 to find the service conductors up to 400 amperes.

Minimum Size 18 Ratings in excess of 400 amperes shall comply with Table 310.16.

Conductors Table 310.12(A) also applies to feeder conductors supplying the entire load.

19 Size the Neutral Conductor. 220.61 310.12(D) states that the neutral service or feeder conductor can be Minimum Size smaller than the ungrounded (hot) conductors, provided the requirements 19 Neutral of 215.2, 220.61, and 230.42 are met.

Conductor 250.24(D)(1) states that the grounded conductor shall not be smaller than specified in Table 250.102(C)(1).

20 Size the Grounding Electrode Conductor (for Service). 250.66 Minimum Size Use line 18 to find the grounding electrode conductor in Table 250.66.

Grounding Size the Equipment Grounding Conductor (for Feeder). 250.122 20 Electrode Use line 17 to find the equipment grounding conductor in Table 250.122.

Conductor Equipment grounding conductor types are listed in 250.118.

18,958

240

79

4 copper

11

UNIT 9 COMPETENCY TEST 1. Answer: 10 Reference: 230.26

19. Answer: ¼ Reference: 312.2

2. Answer: 250.102(C)(1) Reference: 250.102(C)(1)

20. Answer: b) 6 in.

Reference: 110.26(A)(3)

3. Answer:

21. Answer: 6 AWG Reference: 250.102(D) and Table 250.122

d) permitted to be less than 3 ft above the window Reference: 230.9(A) Exception

4. Answer: 5000 Reference: 240.83(C) 5. Answer: d) I, II, or III Reference: 230.62(B) 6. Answer: that of the panelboard Reference: 408.36 7. Answer: 1 ft Reference: 230.51(A) 8. Answer: concentric or eccentric Reference: 250.92(B) 9. Answer: 12 Reference: 230.24(B)(2) 10. Answer: 20 Reference: 250.52(A)(4) 11. Answer: hexagonal Reference: 240.50(C) 12. Answer: 6 Reference: 250.53(B) 13. Answer: clear, evident, and specific Reference: 408.4(A) 14. Answer: goosenecks Reference: 230.54(C) 15. Answer: 30 Reference: 110.26(A)(2) 16. Answer:

a) Under certain conditions, equipment grounding conductors shall be required to be larger than circuit conductors supplying the equipment.

Reference: 250.122

17. Answer: 6½ Reference: 110.26(A)(3) 18. Answer: 8½ Reference: 230.24(A)

12

22. Answer: 30 Reference: 240.51(A) 23. Answer: grounding electrode conductor Reference: Article 100 (Grounding Electrode Conductor) 24. Answer: 25 ohms Reference: 250.53(A)(2) Exception 25. Answer: 115% Reference: 440.12(A) and (A)(1) 26. Answer: 100 amperes Reference: 240.83(B) 27. Answer:

6 AWG. In accordance with Table 310.12(A), the minimum size service conductors are 1/0 AWG copper. The grounding electrode conductor, sized from Table 250.66 for 1/0 copper service-entrance conductors, is 6 AWG copper.

Reference: Table 250.66

28. Answer: main bonding jumper Reference: Article 100 (Bonding Jumper, Main) 29. Answer: c) 75 amperes Reference: 240.6(A) and Table 240.6(A) 30. Answer: 6 Reference: 250.53(A)(3) 31. Answer: 12½ Reference: 250.28(D)(1) and Table 250.102(C)(1) 32. Answer: service disconnecting means Reference: Article 100 (Service Conductors) 33. Answer: 3 Reference: Table 110.26(A) 34. Answer: 2, 2½ Reference: 250.52(A)(7) and 250.53(A)(5)

UNIT 9 COMPETENCY TEST continued 35. Answer: 6 Reference: 250.102(E)(2) 36. Answer: 3 Reference: 250.94(A)(2)

37. Answer: 3 Reference: 344.30(A)(3) 38. Answer:

Emergency Disconnect, Service Disconnect Reference: 230.85

39. Answer:

normally non-currentcarrying metal parts Reference: 250.24( B)

40. Answer: objectionable current Reference: 250.6(A) 41. Answer: structure Reference: Article 100 (Structure)

13

Section 3

MULTIFAMILY DWELLINGS

UNIT 10 COMPETENCY TEST 1. Answer: Equipment Reference: Article 100 (Equipment) 2. Answer: plaque, directory Reference: 230.2(E)

47.25 kW. Note: The minimum clothes dryer demand load, in dwelling unit(s), is 5000 watts (5 kW).

5 x 30 x 31.5% = 47.25 kW. Reference: 220.54 and Table 220.54

3. Answer: 20 in Reference: 210.52(C)(2) and(3)

17. Answer: 12 Reference: 210.52(A)(1)

4. Answer: disconnecting means Reference: Article 100 (Disconnecting Means)

18. Answer: easily ignitable material Reference: 240.24(D)

5. Answer: arc-fault circuit interrupter Reference: Article 100 [Arc-Fault Circuit Interrupter (AFCI)]

19. Answer: approved space Reference: 312.7

6. Answer: 8½ Reference: 230.24(A) 7. Answer: 10 AWG Reference: Table 250.122 8. Answer: 2 AWG Reference: 310.12(B) and Table 310.12(A) 9. Answer: Branch circuits Reference: 210.25(A) 10. Answer: 18 Reference: 250.80 Exception 11. Answer: 2 Reference: 230.6 12. Answer:

57.75 kW. Note: Use 12 kW for any range rated less than 12 kW. 150 (15 x 10) + 130 (13 x 10) + 120 (12 x 10) + 120 (12 x 10) = 520 (total kW) 520 ÷ 40 = 13 (average kW). Table 220.19, Column C for 40 units is 55 kW (15 + 40) 55 x 5% (Note 2) = 2.75 55 + 2.75 = 57.75 kW. Reference: 220.55 and Table 220.55

13. Answer:

hallways, stairways, and outdoor entrances Reference: 210.70(A)(2) Exception

14. Answer: 3 Reference: 230.9(A) 15. Answer: supply Reference: 250.142(A)

14

16. Answer:

20. Answer: induction Reference: 300.20(A) 21. Answer: Interrupting rating Reference: Article 100 (Interrupting Rating) 22. Answer: 4 Reference: 210.52(E)(3) 23. Answer: vertical Reference: 240.33 24. Answer: 2x4 Reference: 410.30(B)(1) 25. Answer: permanent plaque or directory Reference: 230.2(E) 26. Answer:

Hermetic refrigerant motorcompressor Reference: Article 100 (Hermetic refrigerant motor-compressor)

27. Answer: 300 Reference: 422.31(B) 28. Answer: each occupant Reference: 230.72(C) 29. Answer: Service equipment Reference: Article 100 (Service Equipment) 30. Answer: 3, 8 Reference: 410.10(D)(1) 31. Answer:

0.0125 ohms; 0.025 ÷ 1,000 = 0.000025 x 500 = 0.0125 or 0.025 ÷ 2 = 0.0125 Reference: Chapter 9, Table 9

UNIT 10 COMPETENCY TEST continued 32. Answer:

10 AWG copper; cmil = =

2xKxLxI VD 2 x 12.9 x 230 x 5.8 = 9,976 3.45

= 10 AWG copper Reference: 210.19 Informational Note and Table 430.248 33. Answer: 5 Reference: 250.68(C)(1) 34. Answer:

18.9 kW; Column B = 12 x 8 x 32% = 30.72 Column C = 27.

Use the lesser of Column B or Column C. The neutral load is 70% of the maximum unbalanced load. 27 x 70% = 18.9 220.61(B).

Reference: 220.55, Table 220.55, and 220.61(B)

35. Answer:

2.6%. The answer can be derived from either the Ohm’s Law formula or the voltage drop formula. Both are shown below.

VD = 0.00124 x 120 x 2 x 21 = 6.2496 volts 6.2496 ÷ 240 = 0.026 = 2.6% 2xKxLxI cmil 2 x 12.8712 x 120 x 21 = 10,380

VD =

= 6.2496 ÷ 240 = 0.026 = 2.6% Reference: Chapter 9, Table 8 36. Answer: 25 Reference: 210.63 and 210.63(B)(1)

37. Answer: 6 Reference: 230.71(B) 38. Answer: Service lateral Reference: Article 100 (Service Lateral)

15

UNIT 11 COMPETENCY TEST 1. Answer: 4 AWG aluminum Reference: Table 250.122 2. Answer:

42.5 kW. Note: The minimum minimum load for an electric clothes dryer in a dwelling units, is 5000 watts (5 kW). 5 x 25 x 34% = 42.5 kW. Reference: 220.54 and Table 220.54

3. Answer:

17.85 kW. Note: Use 12 kW for any range rated less than 12 kW. 15 + 14 + 12 + 12 = 53 (total kW).

53 ÷ 4 = 13.25 = 13 (average kW).

Table 220.55, Column C for 4 units is 17 kW. 17 x 5% (Note 2) = 0.85 17 + 0.85 = 17.85 kW. Reference: 220.55 and Table 220.55 24,678 volt-amperes. Dishwasher = 1000 VA. Disposer = 7.2 x 115 = 828 VA. Water heater = 0 VA (no neutral load). 1000 + 828 = 1828 VA (each unit). 1828 x 18 x 75% = 24,678 volt-amperes.

Reference: 220.53

58.5 kW; 4.5 (kW) x 50 (units) = 225 (kW); 225 (total kW) x 26% (Table 220.84(B) demand factor) = 58.5 kW. Reference: Table 220.84(B)

10. Answer:

11. Answer:

24,000 VA; 5000 (VA) x 8 (units) x 60% = 24,000 VA.

12. Answer:

23,000 VA; Column C (8 units) = 23 kW; Column B = 8 x 8.75 x 36% = 25.2 kW; 23 x 1000 = 23,000 VA.

13. Answer:

the heat; 5.8 x 115 = 667 VA (blower); 14 x 230 x125% = 4025 VA (compressor); 4.4 x 115 = 506 VA (condenser); 4200 + 667 = 4867 x 8 = 38,936 VA (heat); 667 + 4025 + 506 = 5198 x 8 = 41,584 VA (air-conditioning).

Include the air-conditioning load, omit the heating load.

14. Answer:

600 amperes

15. Answer:

350 kcmil copper. Note: Each ungrounded conductor must have a rating of at least 298.5 amperes (597 ÷ 2 = 298.5). 300 kcmil copper has a rating of only 285 amperes.

Therefore, 350 kcmil, with a rating of 310 amperes, is the minimum size for a parallel set of conductors.

16. Answer:

305 amperes

17. Answer:

2/0 copper; 305 ÷ 2 = 152.5 amperes per neutral conductor.

18. Answer:

2/0 copper

19. Answer:

400 amperes

20. Answer:

600 kcmil copper. Select a copper conductor from Table 310.16 that has an ampacity rating of at least 398 amps.

The minimum size service conductors are 600 kcmil copper.

21. Answer:

300 kcmil copper

22. Answer:

1/0 copper

4. Answer:

5. Answer:

2/0 AWG; 3/0 AWG = 167,800 cmil (Chapter 9, Table 8); 167,800 ÷ 1000 = 167.8 x 4 = 671.2 kcmil (equivalent area). Over 600 through 1100 kcmil copper = 2/0 copper.

Reference: Table 250.66

6. Answer:

15.75 amperes; 5400 ÷ 240 = 22.5; 22.5 x 70% = 15.75.

Reference: 220.54 and 220.61(B)

7. Answer:

35 kW; Column C (20 units) = 35 kW; Column B = 20 x 6.5 x 28% = 36.4 kW. Reference: 220.55 and Table 220.55

8. Answer: Zero Reference: 210.52(F) Exception No. 1 9. Answer:

4/0 AWG aluminum; 500 + 500 = 1000 kcmil (equivalent area). Over 600 through 1100 kcmil copper = 4/0 aluminum.

Reference: Table 250.66

16

Standard Method Load Calculation for Multifamily Dwellings Unit 11 . . . Questions 11 through 15, and 18 1 General Lighting and Receptacle Loads 220.41

1200

Do not include open porches, or unfinished areas not adaptable 3 × (sq ft outside dimensions) for future use as a habitable room or occupiable space 2 Small-Appliance Branch Circuits 220.52(A) At least two small-appliance branch circuits 1500 × (minimum of two) must be included. 210.11(C)(1) 3 Laundry Branch Circuit(s) 220.52(B) Include at least one laundry branch circuit *unless 1500 × *(minimum of one) meeting 210.52(F) Exception No. 1 or 2. 210.11(C)(2)

×

2

×

1

4 Add lines 1, 2, and 3 5

64,800

– 3000 = 5

(line 4)

7

----

64,800 61,800

4

× 25% = 7

9 Total General Lighting and Receptacle Load

----

= 1

28,800

8

= 2

24,000

8

= 3

12,000

(number of units)

×

(number of units)

Lines 5 through 8 utilize the demand factors found in Table 220.45.

----

6

(if 117,000 or less, skip to line 8)

(line 6)

8 (number of units)

– 117,000 = 6

----

× 35% =

8

21,630

= 9

24,630

(line 5, if more than 117,000)

61,800

8

(smaller of line 5 or 117,000)

3000 +

----

21,630

+

(line 7)

(line 8)

10 Fastened-In-Place Appliances Rated 1/4 hp or 500 Watts or Greater 220.53 Use the nameplate rating. water heaters / 32,000 Do not include electric cooking equipment, clothes dryers, space/ heating equipment, air-conditioning / equipment, or electric vehicle supply equipment.

If fewer than four units, put total volt-amperes on line 10.

If four or more units, multiply total volt-amperes by 75%.

dishwashers /

8000

/ / /

/ /

40,000 (volt-amps of four or more)

× 75% = 10

11 Electric Clothes Dryers 220.54 11 (If present, otherwise skip to line 12.) Use 5000 watts or the nameplate rating, whichever is larger.

The neutral demand load is 70% for services and feeders. 220.61(B) 12 Household Electric Cooking Appliances Over 1750 Watts 220.55 12 (If present, otherwise skip to line 13.) Use Table 220.55 and all of the applicable Notes.

The neutral demand load is 70% for services and feeders. 220.61(B) 13 Heating or Air-Conditioning System (Compare the heat and A/C, and omit the smaller.) 220.60 13 Include the air handler when using either one. For heat pumps, include the compressor and the maximum amount of electric heat that can be energized while the compressor is running.

25% of the largest motor 14 Largest Motor (one motor only) 220.50, 440.32 through .35, and is in line 13 × 25% = 14 430.24 through .26 Multiply the volt-amperes of the largest motor. (volt-amps of largest motor) by 25% If 25% of the largest motor is in line 13, leave line 14 blank.

15 Total Volt-Ampere Demand Load: Add lines 9 through 14 to find the minimum required volt-amperes.

15

30,000 24,000 23,000 41,584 ---143,214

16 Minimum Amperes

Minimum Size Divide the total 16 17 Service or 17 volt-amperes by ÷ = Feeder 240.6(A) the voltage. (line 15) (voltage) (minimum amperes) 18 Size the Service or Feeder Conductors. Tables 310.16 through 310.21 350 kcmil Cu Use the tables along with 310.15(A) through (F) to determine conductor size.

Minimum Size 18 If the overcurrent device is rated more than 800 amperes, the conductor ampacity Conductors two paralleled sets must be equal to, or greater than, the rating of the overcurrent device. 240.4(C) 19 Size the Neutral Conductor. 220.61 310.12(D) states that the neutral service or feeder conductor Minimum Size can be smaller than the ungrounded (hot) conductors, provided the 19 Neutral requirements of 215.2, 220.61, and 230.42 are met.

Conductor 250.24(D)(1) states that the grounded conductor shall not be smaller than specified in Table 250.102(C)(1).

20 Size the Grounding Electrode Conductor (for Service). 250.66 Minimum Size Use line 18 to find the grounding electrode conductor in Table 250.66.

Grounding Electrode Size the Equipment Grounding Conductor (for Feeder). 250.122 Conductor . . . or . . .

20 Use line 17 to find the equipment grounding conductor in Table 250.122.

Equipment Grounding Equipment grounding conductor types are listed in 250.118.

Conductor

143,214

240

597

600

2/0 Cu

17

Neutral Load Calculation for Multifamily Dwellings Unit 11 . . . Questions 16 and 17 1 General Lighting and Receptacle Loads 220.41

1200

Do not include open porches, or unfinished areas not adaptable 3 × (sq ft outside dimensions) for future use as a habitable room or occcupiable space 2 Small-Appliance Branch Circuits 220.52(A) At least two small-appliance branch circuits 1500 × (minimum of two) must be included. 210.11(C)(1) 3 Laundry Branch Circuit(s) 220.52(B) Include at least one laundry branch circuit *unless 1500 × *(minimum of one) meeting 210.52(F) Exception No. 1 or 2. 210.11(C)(2)

×

2

×

1

4 Add lines 1, 2, and 3 5

64,800

– 3000 = 5

(line 4)

7

----

64,800 61,800

4

× 25% = 7

9 Total General Lighting and Receptacle Load

----

= 1

28,800

8

= 2

28,800

8

= 3

12,000

(number of units)

(number of units)

Lines 5 through 8 utilize the demand factors found in Table 220.45.

----

6

(if 117,000 or less, skip to line 8)

(line 6)

×

8 (number of units)

– 117,000 = 6

----

× 35% =

8

21,630

= 9

24,630

(line 5, if more than 117,000)

61,800

8

(smaller of line 5 or 117,000)

3000 +

----

21,630

+

(line 7)

(line 8)

10 Fastened-In-Place Appliances Rated 1/4 hp or 500 Watts or Greater 220.53 Use the nameplate rating. / Do not include electric cooking equipment, clothes dryers, space/ heating equipment, air-conditioning / equipment, or electric vehicle supply equipment.

If fewer than four units, put total volt-amperes on line 10.

If four or more units, multiply total volt-amperes by 75%.

dishwashers /

8000

/ / /

/ /

8000 (volt-amps of four or more)

× 75% = 10

6000

11

16,800

12

16,100

13

9384

× 25% = 14

167

15

73,081

11 Electric Clothes Dryers 220.54 (If present, otherwise skip to line 12.) Use 5000 watts or the nameplate rating, whichever is larger.

The neutral demand load is 70% for services and feeders. 220.61(B) 12 Household Electric Cooking Appliances Over 1750 Watts 220.55 (If present, otherwise skip to line 13.) Use Table 220.55 and all of the applicable Notes.

The neutral demand load is 70% for services and feeders. 220.61(B) 13 Heating or Air-Conditioning System (Compare the heat and A/C, and omit the smaller.) 220.60 Include the air handler when using either one. For heat pumps, include the compressor and the maximum amount of electric heat that can be energized while the compressor is running.

667

14 Largest Motor (one motor only) 220.50, 440.32 through .35 and 430.24 through .26 Multiply the volt-amperes of the largest motor. by 25% If 25% of the largest motor is in line 13, leave line 14 blank.

(volt-amps of largest motor)

15 Total Volt-Ampere Demand Load: Add lines 9 through 14 to find the minimum required volt-amperes.

16 Minimum Amperes

Minimum Size Divide the total Service or 16 17 17 volt-amperes by ÷ = Feeder 240.6(A) the voltage. (line 15) (voltage) (minimum amperes) 18 Size the Service or Feeder Conductors. Tables 310.16 through 310.21 Use the tables along with 310.15(A) through (F) to determine conductor size.

Minimum Size 18 If the overcurrent device is rated more than 800 amperes, the conductor ampacity Conductors must be equal to, or greater than, the rating of the overcurrent device. 240.4(C) 19 Size the Neutral Conductor. 220.61 310.12(D) states that the neutral service or feeder conductor Minimum Size can be smaller than the ungrounded (hot) conductors, provided the 19 Neutral requirements of 215.2, 220.61, and 230.42 are met.

Conductor 250.24(D)(1) states that the grounded conductor shall not be smaller than specified in Table 250.102(C)(1).

20 Size the Grounding Electrode Conductor (for Service). 250.66 Minimum Size Use line 18 to find the grounding electrode conductor in Table 250.66.

Grounding Electrode Size the Equipment Grounding Conductor (for Feeder). 250.122 Conductor . . . or . . .

20 Use line 17 to find the equipment grounding conductor in Table 250.122.

Equipment Grounding Equipment grounding conductor types are listed in 250.118.

Conductor

73,081

18

240

305

2/0 Cu

two parallel sets

Optional Method Load Calculation for Multifamily Dwellings Unit 11 . . . Questions 19, 20, and 22 1 General Lighting and Receptacle Loads 220.84(C)(1)

1350

6

= 1

24,300

6

= 2

18,000

6

= 3

9000

6

= 4

25,200

6

= 5

7200

6

= 6

4968

6

= 7

24,000

6

= 8

63,600

= 9

----

= 10

----

= 11

----

12

40,968

Multiply total VA by Table 220.84(B) + = 13 (total volt-amperes from lines 1 through 12) (Table 220.84(B) demand factor) demand factor percentage.

14 House Load (If present; otherwise skip to line 15.)

14 Calculate in accordance with Article 220, Part III. Do not include Table 220.84(B) demand factors.

15 Minimum Amperes Minimum Size Divide the total 16 Service or 16 15 volt-amperes ÷ = Feeder 240.6(A) by the voltage. (lines 13 and 14) (voltage) (minimum amperes)

95,584

2 Small-Appliance Branch Circuits 220.84(C)(2) At least two small-appliance branch circuits must be included. 210.11(C)(1) 3 Laundry Branch Circuit(s) 220.84(C)(2) Include at least one laundry branch circuit *unless meeting 210.52(F) Exception No. 1 or 2. 210.11(C)(2)

4 through 11 Appliances and Motors 220.84(C)(3) and (4)

water heater

Use the nameplate rating of all appliances (fastened in place, permanently connected, or connected to a specific circuit), ranges, wall-mounted ovens, counter-mounted cooking units, motors, water heaters, and clothes dryers.

dishwashers

3×

(sq ft outside dimensions)

1500 × 1500 ×

2

×

1

×

4200

×

1200

×

828

×

4000

×

10,600

×

(minimum of two)

*(minimum of one)

/

(volt-amperes each)

Convert any nameplate rating given in amperes to volt-amperes by multiplying the amperes by the rated voltage.

Do not include any heating or air-conditioning equipment in this section.

/

(volt-amperes each)

disposers

/

(volt-amperes each)

clothes dryers

/

(volt-amperes each)

/

ranges

×

(volt-amperes each)

/ (volt-amperes each)

/ (volt-amperes each)

/ (volt-amperes each)

× × ×

(number of units)

(number of units)

(number of units)

(number)

(number)

(number)

(number)

(number)

(number)

(number)

(number)

12 Heating or Air-Conditioning System (Compare the heat and A/C, and omit the smaller.) 220.84(C)(5) Include the air handler when using either one.

For heat pumps, include the compressor and the maximum amount of electric heat that can be energized while the compressor is running.

13 Total Volt-Ampere Demand Load:

95,584

6828 (volt-amperes each)

217,236

240

×

6

=

(number)

44%

398

400

17 Size the Service or Feeder Conductors. Tables 310.16 through 310.21 Use the tables along with 310.15(B) through (F) to determine conductor size.

Minimum Size 17 If the overcurrent device is rated more than 800 amperes, the conductor ampacity Conductors must be equal to, or greater than, the rating of the overcurrent device. 240.4(C) 18 Size the Neutral Conductor. 220.61 Note: There is no optional method for calculating the neutral conductor.

Minimum Size 310.12(D) states that the neutral service or feeder conductor Neutral 18 can be smaller than the ungrounded (hot) conductors, provided the Conductor requirements of 215.2, 220.61, and 230.42 are met.

250.24(D)(1) states that the grounded conductor shall not be smaller than specified in Table 250.102(C)(1).

Minimum Size 19 Size the Grounding Electrode Conductor. 250.66 Grounding Electrode Use line 17 to find the grounding electrode conductor in Table 250.66.

Conductor . . . or . . . 19 Size the Equipment Grounding Conductor (for Feeder). 250.122 Equipment Grounding Use line 16 to find the equipment grounding conductor in Table 250.122.

Conductor Equipment grounding conductor types are listed in 250.118.

600 kcmil Cu

1/0 Cu

19

Neutral Load Calculation for Multifamily Dwellings Unit 11 . . . Question 21 1 General Lighting and Receptacle Loads 220.41

1350

Do not include open porches, garages, or unfinished areas not 3 × adaptable for future use as a habitable room or occupiable space (sq ft outside dimensions) 2 Small-Appliance Branch Circuits 220.52(A) At least two small-appliance branch circuits 1500 × (minimum of two) must be included. 210.11(C)(1) 3 Laundry Branch Circuit(s) 220.52(B) Include at least one laundry branch circuit *unless 1500 × *(minimum of one) meeting 210.52(F) Exception No. 1 or 2. 210.11(C)(2)

×

2

×

1

4 Add lines 1, 2, and 3 5

51,300

– 3000 = 5

(line 4)

7

----

51,300 48,300

4

× 25% = 7

9 Total General Lighting and Receptacle Load

----

= 1

24,300

6

= 2

18,000

×

6

= 3

9000

(number of units)

(number of units)

Lines 5 through 8 utilize the demand factors found in Table 220.45.

----

6

(if 117,000 or less, skip to line 8)

(line 6)

6 (number of units)

– 117,000 = 6

----

× 35% =

8

16,905

= 9

19,905

(line 5, if more than 117,000)

48,300

8

(smaller of line 5 or 117,000)

3000 +

----

16,905

+

(line 7)

(line 8)

10 Fastened-In-Place Appliances Rated 1/4 hp or 500 Watts or Greater 220.53 Use the nameplate rating. / Do not include electric cooking equipment, clothes dryers, space/ heating equipment, air-conditioning / equipment, or electric vehicle supply equipment.

If fewer than four units, put total volt-amperes on line 10.

If four or more units, multiply total volt-amperes by 75%.

dishwashers /

7200

disposers

/ /

12,168 (volt-amps of four or more)

× 75% = 10

11 Electric Clothes Dryers 220.54

/ / /

4968

9126

11 (If present, otherwise skip to line 12.) Use 5000 watts or the nameplate rating, whichever is larger.

The neutral demand load is 70% for services and feeders. 220.61(B) 12 Household Electric Cooking Appliances Over 1750 Watts 220.55 12 (If present, otherwise skip to line 13.) Use Table 220.55 and all of the applicable Notes.

The neutral demand load is 70% for services and feeders. 220.61(B) 13 Heating or Air-Conditioning System (Compare the heat and A/C, and omit the smaller.) 220.60 13 Include the air handler when using either one. For heat pumps, include the compressor and the maximum amount of electric heat that can be energized while the compressor is running.

14 Largest Motor (one motor only) 220.50, 440.32 through .35 and 430.24 through .26 Multiply the volt-amperes of the largest motor × 25% = 14 by 25%. If 25% of the largest motor is in line 13, leave line 14 blank. (volt-amps of largest motor)

15,750

15

67,692

828

15 Total Volt-Ampere Demand Load: Add lines 9 through 14 to find the minimum required volt-amperes.

14,700 8004 207

16 Minimum Amperes

Minimum Size Divide the total 16 17 Service or 17 volt-amperes by ÷ = Feeder 240.6(A) the voltage. (line 15) (voltage) (minimum amperes) 18 Size the Service or Feeder Conductors. Tables 310.16 through 310.21 Use the tables along with 310.15(A) through (F) to determine conductor size.

Minimum Size 18 If the overcurrent device is rated more than 800 amperes, the conductor ampacity Conductors C must be equal to, or greater than, the rating of the overcurrent device. 240.4(C) 19 Size the Neutral Conductor. 220.61 310.12(D) states that the neutral service or feeder conductor Minimum Size can be smaller than the ungrounded (hot) conductors, provided the 19 Neutral requirements of 215.2, 220.61, and 230.42 are met.

Conductor 250.24(D)(1) states that the grounded conductor shall not be smaller than specified in Table 250.102(C)(1).

20 Size the Grounding Electrode Conductor (for Service). 250.66 Minimum Size Use line 18 to find the grounding electrode conductor in Table 250.66.

Grounding Electrode Size the Equipment Grounding Conductor (for Feeder). 250.122 Conductor . . . or . . .

20 Use line 17 to find the equipment grounding conductor in Table 250.122.

Equipment Grounding Equipment grounding conductor types are listed in 250.118.

Conductor

67,692

20

240

282

300 kcmil Cu

Section 4

COMMERCIAL LOCATIONS

UNIT 12 COMPETENCY TEST 1. Answer: the total ampere ratings of such units.

Reference: 220.11(B)

18. Answer: 20 amperes Reference: 410.153

2. Answer: Chain-supported Reference: 410.14

19. Answer: two Reference: 210.60(B)

3. Answer:

20. Answer: 2, 12 Reference: 410.59(C)

environmental conditions, current, voltage, and temperature Reference: 410.52

4. Answer: electric-discharge lighting Reference: Article 100 (Electric-Discharge Lighting) 5. Answer: luminaire Reference: Article 100 (Luminaire) 6. Answer: 50 Reference: 210.23(B)(2) 7. Answer: 2x4 Reference: 410.30(B)(1) 8. Answer: 30 Reference: 600.5(C)(1) 9. Answer:

0

Reference: 210.52(D) and 210.60(A) 10. Answer: grounded, grounded Reference: 410.90 11. Answer: 150, 2 Reference: 220.46(B) 12. Answer: 300 volts Reference: 410.130(B) 13. Answer: Electric-discharge and LED Reference: 410.24(B)

21. Answer: 20 amperes Reference: 600.5(C)(2) 22. Answer: 20 Reference: 410.30(B)(1) Exception No. 2 23. Answer: 90 volt-amperes Reference: 220.14(I) 24. Answer: listed Reference: 410.64(A) 25. Answer: 6 ft Reference: 210.62 26. Answer: c) II or III Reference: Article 100 (Branch-Circuit Selection Current) 27. Answer: 50 Reference: 410.62(C)(2) 28. Answer: 1200 volt-amperes Reference: 220.14(F) 4,000 volt-amperes The unit load per square foot for a retail occupancy is 1.9.

2,105 × 1.9 = 3,999.5 = 4,000 Do not multiply this number by 125 percent.

Reference: Table 220.42(A)

29. Answer:

14. Answer: 200 volt-amperes Reference: 220.46(A)

30. Answer: 4, 2 Reference: 410.154

15. Answer:

31. Answer: d) 200% Reference: 600.6(B)

7. Two supports in the first 4-foot section and one support in each additional 4-foot section Reference: 410.154

16. Answer: 8 Reference: 410.30(B)(1) Exception No. 1 17. Answer:

a) 100%. Note: The listed reference states that the device must be capable of carrying the starting current of the motor. The key to this question is starting current, not rated-load current.

Reference: 440.22(A)

32. Answer:

c) all conductors have an insulation rating equal to at least the maximum circuit voltage applied to any conductor within the enclosure.

Reference: 300.3(C)(1)

21

UNIT 12 COMPETENCY TEST continued 33. Answer: 3 Reference: 410.68 34. Answer: grounded Reference: 410.90 35. Answer: 20 amperes Reference: 210.21(A) 36. Answer: ½ Reference: 410.116(A)(1) 37. Answer: 25 Reference: 210.63 and 210.63(B)(1) 38. Answer: listed, extra-duty Reference: 406.9(B)(1) 13 Receptacles are calculated at 180 volt-amperes per yoke. The rating of each receptacle is 1.5 amperes (180 ÷ 120 = 1.5). Thirteen receptacles are permitted on a 20-ampere overcurrent protective device (20 ÷ 1.5 = 13.3 = 13).

Reference: 220.14(I)

39. Answer:

22

UNIT 13 COMPETENCY TEST 1. Answer:

65 kVA. Use the total kVA load; no derating factors apply to commercial laundries. 10 x 5 = 50 10 x 1.5 = 15 50 + 15 = 65 kVA Reference: 220.14(A)

2. Answer: 1.9 Reference: Table 220.42(A) Barber shops and beauty parlors are considered retail occupancies.

3. Answer: 600 Reference: 220.14(E) 4. Answer:

17,625 volt-amperes. Table 220.42(A) requires 1.5 volt-amperes per square ft (1.5 x 11,750 = 17,625 VA).

Reference: Table 220.42(A) Clubs are considered restaurant occupancies.

5. Answer:

43.68 kW; 12 + 12 + 10 + 8 + 8 + 1.2 + 1.5 + 10 + 4.5 = 67.2 x 65% = 43.68 Reference: 220.56 and Table 220.56

6. Answer: 150 volt-amperes, 2 Reference: 220.46(B) 7. Answer:

9600 volt-amperes; 52 x 180 = 9360 VA. Use the larger of calculated load or 1 volt-ampere per square foot.

Reference: 220.14(I) and (J)

8. Answer: noncoincident Reference: 220.60 9. Answer:

27,500 volt-amperes; 250 x 180 = 45,000 VA. The first 10,000 voltamperes is rated 100%, the remainder is multiplied by 50%.

45,000 – 10,000 = 35,000 x 50% = 17,500 + 10,000 = 27,500

11. Answer:

15,080 volt-amperes. 320 – 60 = 260 ÷ 5 = 52 x 180 = 9360 voltamperes for non-simultaneous use multioutlet assemblies. 60 x 180 = 10,800 volt-amperes for simultaneous use multioutlet assemblies. 9360 + 10,800 = 20,160 volt-amperes (before demand factors). Apply Table 220.47 demand factors to the total multioutlet assembly load. 20,160 – 10,000 = 10,160 x 50% = 5080 + 10,000 = 15,080 volt-amperes.

Reference: 220.14(H) and 220.47

12. Answer:

2 AWG. Column C = 27 kW; Column B = 30.72 kW (12 x 8 x 32%). Use the smaller rating, 27 kW. 27 x 1000 = 27,000 ÷ 240 = 115 A. Table 310.16 requires 2 AWG THW copper conductors.

Reference: Table 220.55, Note 7 and Table 310.16

13. Answer:

24,950 volt-amperes. Each room has 540 sq ft (18 x 30). The total area for all 50 rooms is 27,000 sq ft (50 x 540). The guest room general lighting load, computed by Table 220.42(A), is 45,900 volt-amperes (27,000 x 1.7).

This load can be derated using Table 220.45. The first 20,000 VA is derated to 12,000 VA (20,000 x 60%). The The remainder is derated to 12,950 VA (25,900 x 50%). The total calculated load for the guest rooms in this motel is 24,950 VA (12,000 + 12,950).

Note: The room receptacles are included in the general lighting load (220.44).

Reference: Table 220.42(A) and Table 220.45

14. Answer: 8000 volt-amperes (200 × 40 = 8000) Reference: 220.14(G)

Reference: 220.14(I) and Table 220.47 15. Answer: 13,600 volt-amperes. The unit load for a gymnasium-type occupancy is 1.7 volt-amperes per ft2 .

Reference: 8000 x 1.7 = 13,600 Reference: Table 220.42(A) Auditoriums are consider- 16. Answer: ed gymnasium-type occupancies.

Reference:

10. Answer:

the maximum volt-ampere rating of the equipment and lamps for which the luminaire(s) is rated 220.14(D) 125% of the largest motor plus the sum of the other loads 220.18(A)

23

UNIT 13 COMPETENCY TEST continued 26. Answer:

17. Answer: 180 volt-amperes Reference: 220.14(I) 18. Answer:

18 kW; 12 + 2.8 + 4.2 + 0.8 + 0.8 + 6 = 26.6 x 65% = 17.29 kW. Note: The feeder demand load can never be smaller than the rating of the two largest pieces of equipment. The two largest pieces (range and water heater) have a total rating of 18 kW. Reference: 220.56

19. Answer:

90,000 volt-amperes; 150 x 15 x 25 = 56,250 (total sq ft). The hospital general lighting load, computed by Table 220.42(A), is 90,000 VA (56,250 x 1.6). This load cannot be derated using Table 220.45. Table 220.42(A) already includes the additional 25% for continuous loads.

45,764 volt-amperes.

Electric heat: 10,000. Blower motor: 4 × 208 × 1.732 = 1441 VA. Each heating unit = 11,441. Total heating = 45,764 VA. Compressor: 19.6 × 208 × 1.732 × 125% = 8826 VA. Condenser: 3 × 208 × 1.732 = 1081 VA. Air handler: 4 × 208 × 1.732 = 1441 VA. Each air conditioning unit = 11,384 VA. Total air conditioning = 43,392 VA. Reference: 220.60

27. Answer:

350 amperes

28. Answer:

2/0 AWG. The minimum required ampacity is 304 amperes. A parallel run of 1/0 AWG conductors only has a combined rating of 300 amperes.

Therefore, the next larger conductor is required.

29. Answer:

1/0 copper; Since the conductors are paralleled, each neutral requires 81 amperes (162 ÷ 2).

Size 4 AWG copper conductors would carry the current, but the smallest conductor permitted to be connected in parallel is 1/0 AWG. See 250.24(D)(2) and 310.10(G)(1)

30. Answer:

2 AWG. The combined area for the paralleled service-entrance conductors is 266.2 kcmil (133.1 + 133.1).

Reference: Table 220.42(A) 20. Answer: the total ampere ratings of such units Reference: 220.11(B) 21. Answer:

26,690 volt-amperes; 200 x 180 = 36,000 VA (receptacles) 80 ÷ 5 = 16 x 180 = 2880 VA (multioutlet assemblies) 25 x 180 = 4500 VA (simultaneously used multioutlet assemblies); 36,000 + 2880 + 4500 = 43,380 VA (before applying the demond factors of 220.47); 43,380 – 10,000 = 33,380 x 50% = 16,690 + 10,000 = 26,690 VA.

Reference: 220.14(H), 220.14(I) and Table 220.47 22. Answer:

24,700 volt-amperes; 1.3 x 19,000 = 24,700 VA Reference: Table 220.42

23. Answer:

3600 volt-amperes; 150 = 3,600 VA Reference: 220.46(B)

48 ÷ 2 = 24 x

24. Answer:

1800 volt-amperes; 15 x 120 = 1800 VA Reference: 220.14(F)

25. Answer:

The four air-conditioner compressor motors and the four condenser fan motors. See question number 26.

Reference: 220.60

24

Nondwelling Feeder/Service Load Calculation Unit 13 . . . Questions 21 through 28, and 30 1 Receptacle Load (noncontinuous) 220.14(I) Multiply each single or multiple receptacle on one strap by 180 volt-amperes.

1 Multiply each single piece of equipment comprised of four or more receptacles by 90 VA per receptacle.

2 Fixed Multioutlet Assemblies (noncontinuous) 220.14(H) Where not likely to be used simultaneously, multiply each 5-ft section by 180 volt-amperes.

2 Where likely to be used simultaneously, multiply each 1-ft section by 180 volt-amperes.

3 Receptacle Load Demand Factor (for nondwelling receptacles) 220.47 If the receptacle load is more than 10,000 volt-amperes, apply the demand factor from Table 220.47.

3 Add lines 1 and 2. Multiply the first 10 kVA or less by 100%. Then multiply the remainder by 50%.

4 Receptacle Load (office buildings only) 220.14 (J) (1) Calculate the demand in line 3. (2) Multiply 1 volt-ampere per sq ft 1× = 4 (sq ft outside dimensions) and add to line 4. (3) Compare lines 3 and 4, and omit the smaller.

5 General Lighting Load Table 220.42(A) Multiply the VA unit load (for the type of occupancy) by the sq ft outside dimensions. This × = 5 table already includes the additional 25% for continuous loads. (VA unit load) (sq ft outside dimensions) 6 Lighting Load Demand Factors 220.45. Apply Table 220.45 demand factors to certain portions of 6 hotels, motels, apartment houses (without provisions for cooking), and storage warehouses.

Do not include areas in hotels and motels where the entire lighting will be used at one time.

7 Track Lighting (in addition to general lighting) 220.46(B) Include 150 volt-amperes for every 2 ft, ÷2 × 150 = 7 (total linear ft) or fraction thereof, of lighting track.

8 Sign or Outline Lighting Outlet (where required) 220.14(F) 8 Each commercial building (or occupancy) accessible to pedestrians must have at least one outlet per tenant space entrance. 600.5(A) Each outlet must be at least 1200 volt-amperes.

9 Show-Window Lighting 220.46(A) Include at least 200 volt-amperes for each linear foot, × 200 = 9 (total linear ft of show window) measured horizontally along the show window’s base.

10 Continuous Loads 215.2(A)(1), 215.3, and 230.42(A)(1) Multiply the continuous load volt-amperes (listed above) by 25%. × 25% = 10 (General-purpose receptacles are not considered continuous.) (total continuous load volt-amperes) 11 Kitchen Equipment 220.56 11 Multiply three or more pieces of equipment by the Table 220.56 demand factor (%).

1.3

36,000 7380 26,690

----

----

19,000

24,700

48

----

24

3600 1800

----

----

5400

1350 ----

Use Table 220.55 for household cooking equipment used in instructional programs. Table 220.55, Note 5

12 Noncoincident Loads 220.60. The smaller of two (or more) noncoincident loads can be omitted, as long as they will never be energized simultaneously (such as certain portions of heating and A/C systems). 12 Calculate fixed electric space-heating loads at 100% of the total connected load. 220.51 13 Motor Loads 220.11(A), 430.24, 430.25, 430.26, and Article 440 Multiply the largest motor (one motor only) by 25% and add it to the load.

13 If 25% of the largest motor is in line 12, leave line 13 blank.

14 All Other Loads.

14 Add all other noncontinuous loads into the calculation at 100%.

Multiply all other continuous loads (operating for 3 hours or more) by 125%.

45,764

15 Total Volt-Ampere Demand Load: Add lines 3 through 14 to find the minimum required volt-amperes.

109,264

15

360 5000

16 Minimum Amperes

Minimum Size Divide the total 16 17 Service or 17 volt-amperes by ÷ = Feeder 240.6(A) the voltage. (line 15) (voltage) (minimum amperes) 18 Size the Service or Feeder Conductors. Tables 310.16 through 310.21 AWG Cu Use the tables along with 310.15(A) through (F) to determine conductor size.

Minimum Size 18 If the overcurrent device is rated more than 800 amperes, the conductor ampacity Conductors two paralleled sets must be equal to, or greater than, the rating of the overcurrent device. 240.4(C) 19 Size the Neutral Conductor. 220.61 The neutral service or feeder conductor can be smaller than the ungrounded Minimum Size (hot) conductors, but not smaller than the maximum unbalanced load determined 19 Neutral

by Article 220. 250.24(C)(1) states that the grounded conductor shall not be smaller Conductor than specified in Table 250.102(D)(1). A further demand factor is permitted for any neutral load over 200 amperes.

20 Size the Grounding Electrode Conductor (for Service). 250.66 Minimum Size Use line 18 to find the grounding electrode conductor in Table 250.66.

Grounding Electrode Size the Equipment Grounding Conductor (for Feeder). 250.122 Conductor . . . or . . .

AWG 20 Use line 17 to find the equipment grounding conductor in Table 250.122.

Equipment Grounding Equipment grounding conductor types are listed in 250.118.

Conductor

109,264

360

350

304

2/0

2

Cu

25

Nondwelling Neutral Load Calculation Unit 13 . . . Question 29 1 Receptacle Load (noncontinuous) 220.14(I) Multiply each single or multiple receptacle on one strap by 180 volt-amperes.

1 Multiply each single piece of equipment comprised of four or more receptacles by 90 VA per receptacle.

2 Fixed Multioutlet Assemblies (noncontinuous) 220.14(H) Where not likely to be used simultaneously, multiply each 5-ft section by 180 volt-amperes.

2 Where likely to be used simultaneously, multiply each 1-ft section by 180 volt-amperes.

3 Receptacle Load Demand Factor (for nondwelling receptacles) 220.47 If the receptacle load is more than 10,000 volt-amperes, apply the demand factor from Table 220.47.

3 Add lines 1 and 2. Multiply the first 10 kVA or less by 100%. Then multiply the remainder by 50%.

4 Receptacle Load (office buildings only) 220.14 (J) (1) Calculate the demand in line 3. (2) Multiply 1 volt-ampere per sq ft 1× = 4 (sq ft outside dimensions) and add to line 4. (3) Compare lines 3 and 4, and omit the smaller.

5 General Lighting Load Table 220.42(A) Multiply the VA unit load (for the type of occupancy) by the sq ft outside dimensions. This × = 5 table already includes the additional 25% for continuous loads. (VA unit load) (sq ft outside dimensions) 6 Lighting Load Demand Factors 220.45. Apply Table 220.45 demand factors to certain portions of 6 hotels, motels, apartment houses (without provisions for cooking), and storage warehouses.

Do not include areas in hotels and motels where the entire lighting will be used at one time.

7 Track Lighting (in addition to general lighting) 220.46(B) Include 150 volt-amperes for every 2 ft, ÷2 × 150 = 7 (total linear ft) or fraction thereof, of lighting track.

8 Sign or Outline Lighting Outlet (where required) 220.14(F) 8 Each commercial building (or occupancy) accessible to pedestrians must have at least one outlet per tenant space entrance. 600.5(A) Each outlet must be at least 1200 volt-amperes.

9 Show-Window Lighting 220.46(A) Include at least 200 volt-amperes for each linear foot, × 200 = 9 (total linear ft of show window) measured horizontally along the show window’s base.

10 Continuous Loads 215.2(A)(1), 215.3, and 230.42(A)(1) Multiply the continuous load volt-amperes (listed above) by 25%. × 25% = 10 (General-purpose receptacles are not considered continuous.) (total continuous load volt-amperes) 11 Kitchen Equipment 220.56 11 Multiply three or more pieces of equipment by the Table 220.56 demand factor (%).

1.3

36,000 7380 26,690

----

----

19,000

24,700

48

24

---3600 1800

----

----

5400

1350

Use Table 220.55 for household cooking equipment used in instructional programs. Table 220.55, Note 5

12 Noncoincident Loads 220.60. The smaller of two (or more) noncoincident loads can be omitted, as long as they will never be energized simultaneously (such as certain portions of heating and A/C systems). 12 Calculate fixed electric space-heating loads at 100% of the total connected load. 220.51 13 Motor Loads 220.11(A), 430.24, 430.25, 430.26, and Article 440 Multiply the largest motor (one motor only) by 25% and add it to the load.

13 If 25% of the largest motor is in line 12, leave line 13 blank.

14 All Other Loads.

14 Add all other noncontinuous loads into the calculation at 100%.

Multiply all other continuous loads (operating for 3 hours or more) by 125%.

15 Total Volt-Ampere Demand Load: Add lines 3 through 14 to find the minimum required volt-amperes.

15

------------58,140

16 Minimum Amperes

Minimum Size Divide the total 16 17 Service or 17 volt-amperes by ÷ = Feeder 240.6(A) the voltage. (line 15) (voltage) (minimum amperes) 18 Size the Service or Feeder Conductors. Tables 310.16 through 310.21 Use the tables along with 310.15(A) through (F) to determine conductor size.

Minimum Size 18 If the overcurrent device is rated more than 800 amperes, the conductor ampacity Conductors must be equal to, or greater than, the rating of the overcurrent device. 240.4(C) 19 Size the Neutral Conductor. 220.61 The neutral service or feeder conductor can be smaller than the ungrounded Minimum Size (hot) conductors, but not smaller than the maximum unbalanced load determined 19 Neutral

by Article 220. 250.24(D)(1) states that the grounded conductor shall not be smaller Conductor than specified in Table 250.102(C)(1). A further demand factor is permitted for any neutral load over 200 amperes.

20 Size the Grounding Electrode Conductor (for Service). 250.66 Minimum Size Use line 18 to find the grounding electrode conductor in Table 250.66.

Grounding Electrode Size the Equipment Grounding Conductor (for Feeder). 250.122 Conductor . . . or . . .

20 Use line 17 to find the equipment grounding conductor in Table 250.122.

Equipment Grounding Equipment grounding conductor types are listed in 250.118.

Conductor

58,140

26

360

162

1/0 Cu

two paralleled sets

UNIT 14 COMPETENCY TEST 1. Answer: first Reference: 250.30(A)(1) and (5)

18. Answer: 50 kVA Reference: 450.13(B)

2. Answer: three Reference: 408.54

19. Answer: 30 Reference: 110.26(A)(1)(a)

3. Answer: damaged or contaminated Reference: 110.12(B)

20. Answer: 115 Reference: 445.13(A)

4. Answer:

21. Answer: 6 Reference: 110.26(A)(3)

grounded conductor, grounded conductor Reference: 250.30 Informational Note No. 1

5. Answer:

2 (or one entrance at each end of the working space) Reference: 110.26(C)(2)

6. Answer: four times (or 400%) Reference: Table 450.3(B) Note 3 7. Answer: 30 Reference: 110.26(A)(2) 8. Answer: bushing Reference: 445.16 9. Answer: orange Reference: 110.15 10. Answer: 1000 amperes Reference: 230.95 11. Answer: grounded Reference: 250.104(D)(1) 12. Answer: 5 Reference: 368.30 13. Answer: 18 ft Reference: 230.24(B)(4) 14. Answer: guarded Reference: Article 100 (Guarded) 15. Answer: 800 Reference: 240.4(C) 16. Answer: Table 312.6(B)(2) Reference: 408.55(A) 17. Answer: separately derived system Reference: Article 100 (Separately Derived System)

22. Answer: 50 Reference: 368.17(B) Exception 23. Answer: durable and visible Reference: 240.83(A) 24. Answer: 6½ Reference: 110.26(A)(3) 25. Answer: 42 (3½ ft = 42 in.)

Reference: Table 110.26(A)(1) 26. Answer: Class 2 or Class 3 transformers Reference: 450.14 27. Answer: 4 Reference: 368.10(C)(2)(b) 28. Answer: Switchboard Reference: Article 100 (Switchboard) 29. Answer: 15 kW Reference: 445.13(B) 30. Answer: 6 Reference: 110.26(E)(1)(a) 31. Answer: 3 Reference: 408.18(A) 32. Answer: 12½% Reference: 250.28(D)(1) and Note 1. Under Table 250.102(C)(1) 33. Answer: enclosed Reference: Article 100 (Enclosed) 34. Answer: 6 Reference: 368.10(C)(2)(a) 35. Answer: vented portion Reference: 450.10(A)

27

UNIT 14 COMPETENCY TEST continued 36. Answer: 1000 amps Reference: 110.16(B) 37. Answer: 110.25 Reference: 450.14 38. Answer: 800, 25 Reference: 110.26(C)(3)

28

Section 5

SPECIAL OCCUPANCIES, AREAS, AND EQUIPMENT

UNIT 15 COMPETENCY TEST 1. Answer: Class I, Division 1 or Zone 1 Reference: 513.3(A)

16. Answer: 10 Reference: 501.15(B)(2)

2. Answer: Class I, Division 2 Reference: 500.8(B)(4)

17. Answer: 5 Reference: 516.29(2)

3. Answer: Class I, Division 2 Reference: 500.5(B)(2)(1)

18. Answer: 502.100(B) Reference: 503.100

4. Answer: ¾ Reference: 344.28

19. Answer: 18, 20 Reference: Table 514.3(B)(1)

5. Answer: Class I, Division 1 or Zone 1 Reference: Table 515.3

20. Answer: 5, 10 Reference: Table 515.3

6. Answer: five Reference: 500.8(E)(1)

21. Answer: dusttight Reference: Article 100 (Dusttight)

7. Answer: threaded bosses Reference: 502.10(A)(3)

22. Answer: 3, 20 Reference: 516.29(4)

8. Answer: 2 Reference: 501.15(C)(3)

23. Answer: 18 Reference: 513.10(C)(1)

9. Answer: 5, 5 Reference: 513.3(C)(1)

24. Answer: Class II, Division 1 Reference: 500.5(C)(1)(1)

10. Answer: Dust-ignitionproof Reference: Article 100 (Dust-ignitionproof)

25. Answer: 18 Reference: Table 511.3(C)

11. Answer:

5/8 26. Answer: Reference: 501.15(C)(3)

flammable gases, flammable liquidproduced vapors, or combustible liquid-produced vapors Reference: 500.5(B)

12. Answer: 12 Reference: 511.7(B)(1)(b) 13. Answer: Class III, Division 1 Reference: 500.5(D)(1)(b) Any five of the following: explosionproof equipment, dust-ignitionproof, dusttight, purged and pressurized, intrinsic safety, nonincendive (circuit, equipment, and component), oil immersion, hermetically sealed, or flammable gas detection system.

Reference: 500.7(A) through (K)

27. Answer: 18 Reference: 513.3(B) 28. Answer: 20, 100 Reference: 514.11(A) 29. Answer: 500 Reference: Article 100 (Combustible Dust)

14. Answer:

30. Answer: surface temperatures Reference: 503.5

15. Answer: nonincendive circuit Reference: Article 100 (Nonincendive Circuit)

29

UNIT 16 COMPETENCY TEST 1. Answer: oil-resistant Reference: 517.78(B) 2. Answer: 10 seconds Reference: 517.32(B) 3. Answer: 10 AWG Reference: 517.14 4. Answer: critical branch Reference: Article 100 (Critical Branch) 5. Answer: color or marking Reference: 517.31(E) 6. Answer: Patient-equipment grounding point Reference: Article 100 (Patient-equipment Grounding Point) 7. Answer:

connected to an equipment grounding conductor Reference: 517.62

8. Answer: 50, 100.

Reference: 517.72(A) 9. Answer: 2 Reference: 517.19(A) 10. Answer: 6, 7½ Reference: Article 100 (Patient Care Vicinity) 11. Answer: 3.7, 5 Reference: 517.160(B)(1) listed and identified as "tamperresistant", listed tamper-resistant Reference: 517.18(C)

12. Answer:

13. Answer: 2 Reference: Article 100 (Category 2 Space under Patient Care Space) 14. Answer: 5 Reference: 517.60(A)(1) 15. Answer: 100 percent Reference: 517.17(C) 16. Answer: 30 amperes Reference: 517.72(C) 17. Answer: life safety branch Reference: Article 100 (Life Safety Branch) 18. Answer: ambulatory health care occupancy Reference: Article 100 (Ambulatory Health Care Occupancy)

30

19. Answer: flammable anesthetizing location Reference: Article 100 (Location, Anesthetizing, Flammable) 20. Answer: 14 Reference: 517.19(B)(1) 21. Answer: 100 volts Reference: 517.13(B)(1)(3) 22. Answer: 24 volts Reference: 517.63(D) 23. Answer: essential electrical system Reference: Aricle 100 (Essential Electrical System) 24. Answer: 10 AWG Reference: 517.19(D) 25. Answer: 60 amperes Reference: 517.71(B) 26. Answer: eight Reference: 517.18(B)(1) 27. Answer: 1 Reference: Article 100 (Category 1 Space under Patient Care Space) 28. Answer: 150, 120 Reference: 517.42(B)(2) 29. Answer: 20 Reference: 517.74(B) 30. Answer: 3 Reference: 517.61(A)(7) 31. Answer: ground-fault current Reference: 517.13(A) 32. Answer: life safety, equipment Reference: 517.42(A) 33. Answer: 50, 100.

Reference: 517.73(A) 34. Answer: reference grounding points Reference: 517.19(H) 35. Answer: Wet procedure location Reference: Article 100 (Loacation, Wet Procedure) 36. Answer: 36 Reference: 517.19(C)(1)

UNIT 17 COMPETENCY TEST 1. Answer: the proper connections Reference: 430.9(A)

19. Answer: 125% Reference: 430.22

2. Answer: 3 Reference: 460.3(A)

20. Answer: industrial machine Reference: Article 100 (Machinery, Industrial)

3. Answer: a) I only Reference: 392.12

21. Answer: 20 Reference: 630.42(C)

4. Answer: 1½ Reference: 610.21(B)

22. Answer: cable tray clamp Reference: 392.18(G)

5. Answer: can be started Reference: 430.7(B)(1)

23. Answer: 500% Reference: 430.72(C)(4)

6. Answer: 3 hours Reference: 450.42

24. Answer: 2½ Reference: 610.57

7. Answer: b) II only Reference: 230.71(B)

25. Answer: 1½ hours Reference: 450.45(E)

8. Answer: 50 volts, 1 minute Reference: 460.6(A)

26. Answer: 50% Reference: 630.31(A)(1)

9. Answer: 115% Reference: 430.110(A)

27. Answer: transversely, vertically Reference: 392.18(D)

10. Answer: 600 amperes Reference: Table 392.60(B), Footnote to table

28. Answer: Table 430.22(E) Reference: 430.22(E)

11. Answer: 430.52 and 430.53 Reference: 670.4(C)

29. Answer: 3 hours Reference: 450.43(A)

12. Answer: 125% Reference: 669.5

30. Answer: Barriers Reference: 430.97(E)

13. Answer: 100 kVA Reference: 450.46

31. Answer: Table 430.52(C)(1) Reference: 610.42(A)

14. Answer: 200% Reference: 630.12(B)

32. Answer: 400% Reference: 430.35(A)

15. Answer: 26 amperes Reference: Table 430.250

33. Answer: c) III only Reference: 460.6(B)

16. Answer: 135% Reference: 460.8(A)

34. Answer: locked-rotor current Reference: 430.82(A)

17. Answer: 7½ hp Reference: 610.43(D) 18. Answer: 4 Reference: 450.43(B)

35. Answer: vented portion Reference: 450.10(A) 36. Answer: 30 Reference: 240.21(B)(4)(9)

31

UNIT 17 COMPETENCY TEST continued 37. Answer: 1/0 Reference: 250.102(C)(2) and Table 250.102(C)(1) racewayy, cable, handole enclosure, or underground box Reference: 230.7

38. Answer:

39. Answer: 1/0 Reference: 250.122(F)(1)(b) and Table 250.122 40. Answer: 2 AWG Reference: 250.64(D)(1) and Table 250.66

32

UNIT 18 COMPETENCY TEST 1. Answer: manufactured building Reference: Article 100 (Building, Manufactured)

19. Answer: point of attachment Reference: 545.6 and Exception

2. Answer: 1 Reference: 551.71(A)

20. Answer: 150 Reference: 520.25(C)

3. Answer: 2 Reference: 550.32(F)

21. Answer: within sight from Reference: 550.32(A)

4. Answer: two-fer Reference: Article 100(Two-Fer)

22. Answer: 8 AWG Reference: 540.13

5. Answer: dust, dust Reference: 547.22

23. Answer: 12,000, 2400 Reference: 551.73(A)

6. Answer: 8 Reference: 520.72

24. Answer: 50-ampere receptacle Reference: 551.71(C)

7. Answer: 590 Reference: 518.3

25. Answer: floating building Reference: Article 100 (Building, Floating)

8. Answer: 70 Reference: 551.71(B) 9. Answer: mobile home Reference: Article 100 (Mobile Home) 10. Answer:

no closer than 5 ft horizontally from and adjacent to the structure served

Reference: 555.4 11. Answer: readily accessible Reference: 520.21(2) 12. Answer: 6 Reference: 525.21(A) 13. Answer: 30 Reference: 540.12 14. Answer: 21, 36½ Reference: 550.10(D) 15. Answer: b) I only Reference: 520.9

26. Answer: 50 Reference: 550.10(A) 27. Answer: 15 Reference: 525.5(B)(1) 28. Answer: 35- or 70-mm, 13/8, 5.4 Reference: Article 100 (Projector, Professional-Type) 29. Answer: 10 AWG Reference: 545.4(B) 30. Answer: 8 Reference: 547.21 31. Answer: 20, 40 Reference: 551.71(C) 32. Answer: 20 amperes Reference: 520.41(A) 33. Answer: 12, 6 Reference: 210.65(B)(2)

16. Answer: 30 Reference: 555.33(A)(4) 17. Answer: 100 Reference: 518.2(B) 18. Answer: 3, 18 Reference: 551.79

33

UNIT 19 COMPETENCY TEST 1. Answer: entirely on or above the ground Reference: Article 100

21. Answer: 8 to 12 Reference: 604.100(A)(1)

2. Answer: continuous, 125 Reference: 625.41

22. Answer: 18 Reference: 680.23(A)(5)

3. Answer: 5 Reference: 680.41(A)

23. Answer: 14 Reference: 600.9(A)

4. Answer: grounded metal barrier Reference: 680.23(A)(2)

24. Answer: 5, 5 Reference: 680.22(B)(3)

5. Answer: intermittent Reference: 620.61(B)(1)

25. Answer: 5 Reference: 680.57(C)(1)

6. Answer: 50 Reference: 600.32(J)(1)(2)

26. Answer: 200°C (or 392°F) Reference: 620.11(A) and (A)(1)

7. Answer: 5, 12 Reference: 680.26(B)(7)

27. Answer: 5, 12 Reference: 680.22(B)(1)

8. Answer: 6 Reference: 680.62(E)

28. Answer: 125% Reference: 645.5(A)

9. Answer:

29. Answer:

10. Answer: 18, 24 Reference: 625.50

30. Answer: primary pad Reference: Article 100 (Primary Pad)

11. Answer: forming shell Reference: Article 100 (Forming Shell)

31. Answer: 30 amperes Reference: 600.5(C)(1)

12. Answer: d) 200% Reference: 600.6(B)

32. Answer: listed potting compound Reference: 680.23(B)(2)(b)

13. Answer: 5, 5 Reference: 640.10(A)

33. Answer: 125%, 100% Reference: 695.6(B)(1)

14. Answer: 6, 20 Reference: 680.22(A)(1)

34. Answer: 5, 5 Reference: 680.22(C)

15. Answer: 15% Reference: 695.7(A)

35. Answer: 605 Reference: 605.1(A)

16. Answer: 7½ Reference: 680.43(B)(1)(b)

36. Answer: 4, 8 in.

Reference: 680.24(A)(2)(a)

enclosed to protect against accidental contact Reference: 620.4

17. Answer: 6 Reference: 620.44(2) 18. Answer: 15 Reference: 645.5(B)(1) 19. Answer: accessible Reference: 680.73 20. Answer: 20 Reference: 680.22(A)(4)

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no fewer than one more than the number of conduit entries Reference: 680.24(D)

37. Answer: 15 Reference: 620.32 38. Answer: Reference:

6 647.7(A)(3)

FINAL EXAM 1 1. No handhole shall be required in a metal pole, supporting a luminaire, that is ft or less in height above grade that is provided with a hinged base.

trays or between the cable tray or between the cable tray and the raceway(s) or the equipment shall not exceed _______ ft.

2. Where run across the top of framing members, or across the face of rafters or studding, within ft of the floor or horizontal surface, in an attic that has permanent stairs, nonmetallic-sheathed cable shall be protected by substantial guard strips that are at least as high as the cable.

13. In dwelling units, hallways of ft or more in length shall have at least one receptacle outlet.

3. Mandatory NEC rules are those that identify actions that are specifically required or prohibited and are characterized by the use of the terms .

4.

In other than dwelling units, in addition to other arcflash hazard warning requirements in this section, a permanent label shall be field or factory applied to service equipment rated amps or more.

5. A location temporarily subject to dampness or wetness, as in the case of a building under construction, is classified as a(n) location.

6. Kitchen countertop receptacle outlets in dwelling units shall be installed so that no point along the wall line is more than in., measured horizontally from a receptacle outlet in that space.

7.

In hazardous (classified) locations, NPT threaded entries into explosionproof equipment shall be made up with at least threads fully engaged.

8. The disconnecting means for motor circuits rated 1000 volts, nominal, or less, shall have an ampacity rating of at least of the full-load current rating of the motor.

9. The life safety and critical branches of a hospital essential electrical system shall be installed and connected to the alternate power source specified in 517.41(A) and (B) so that all specified functions for the life safety and critical branches are automatically restored to operation within after interruption of the normal source.

10. Where an equipment bonding jumper is installed on the outside of a raceway, the length shall not exceed ft and shall be routed with the raceway or enclosure.

11. A surface-mounted incandescent or LED luminaire installed on the ceiling of a clothes closet must have a minimum clearance of in. between the luminaire and the nearest point of the clothes closet storage space.

12. Where cable trays support individual conductors or multiconductor cables and where the conductors or multiconductor cables pass from one cable tray to another, or from a cable tray to raceway(s) or from a cable tray to equipment where the conductors are terminated, the distance between the cable

14. A bathroom is an area that includes: I. a tub and a toilet.

II. a sink and a toilet.

III. a toilet and a shower. a) I only b) II only c) either I or III d) I, II, and III 15. An outdoor motor fuel dispensing device is considered to be a Class I, Division 2 location up to in. above grade level within ft horizontally in all directions from the dispenser enclosure.

16. Where nonmetallic-sheathed cable is run at angles with joists in unfinished basements and crawl spaces, it shall be permissible to secure cables not smaller than two conductors directly to the lower edges of the joists.

17. The ampacity of the supply conductors for a resistance welder that can be operated at different times at different values of primary current or duty cycle shall not be less than of the rated primary current for seam and automatically fed welders.

18. Service conductors installed as open conductors shall have a clearance of not less than ft from windows that are designed to be opened.

19. The is the connection between the grounded circuit conductor and the equipment grounding conductor, or the supply-side bonding jumper, or both at the service.

20. For installations within or behind a surface o f noncombustible material, boxes shall be made so that the front edge of the box will not be set back of the finished surface more than in.

21. Each Category 2 space patient bed location in a health care facility be provided with a minimum of receptacle(s).

22. Plug fuses of and rating shall be identified by a hexagonal configuration of the window, cap, or other prominent part to distinguish them from fuses of higher ampere ratings.

23. Branch-circuits that supply neon tubing installations shall not be rated in excess of .

24. The width of the working of space in front of electrical equipment, operating at 1000 volts or less, shall be or 30 in., whichever is greater.

25. For each major repair garage floor, the entire area up to a level of in. above the floor shall be classified as Class I, Division 2 if ventilation is not provided.

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FINAL EXAM 1 continued 26. One 15-ampere-rated duplex receptacle may be installed on a ampere branch-circuit.

27.

is defined as connected to establish electrical continuity and conductivity.

28. In dormitory units, all nonlocking-type 125- and 250volt, 15- and 20-ampere receptacles shall be ______ .

openings, fireplaces, stationary appliances, and fixed cabinets that do not have countertops or similar work surfaces shall have a receptacle outlet.

40. Busways shall be securely supported at intervals not exceeding ft unless otherwise designed and marked.

29. If it is unlikely that two or more loads wil be in use simultaneously, it shall be permissible to use only the largest load(s) that will be used at one time for calculating the total load of a feeder or service.

41. All exposed lamps in theater dressing or makeup areas including rooms where they are less than ft from the floor, shall be equipped with openend guards riveted to the outlet box cover or otherwise sealed or locked in place.

30. Branch-circuit conductors that supply a single motor used in a continuous duty application shall have an ampacity of not less than of the motor’s fullload current rating as determined by 430.6(A)(1).

42. When calculating track lighting loads for a commercial service, an additional load of volt-amperes shall be included for every ft of lighting track or fraction thereof.

31. A clearly labeled emergency shutoff or control switch for the purpose of stopping the motor(s) that provide power to the recirculation system and jet system shall be installed at a point readily accessible to the users and at least ft away, adjacent to, and within sight of the spa or hot tub for other than one-family dewllings.

43. In aircraft maintenance and storage hangars, the area within ft horizontally from aircraft power plants or aircraft fuel tanks shall be classified as a Class I, Division 2 or Zone 2 location that shall extend upward from the floor to a level ft above the upper surface of wings and engine enclosures.

32. Where are installed in a box, each section shall be considered as a separate box.

44. The walls and roofs of transformer vaults shall be constructed of materials that have approved structural strength for the conditions with a minimum fire resistance of .

33. In a location where flammable anesthetics are employed, the entire area shall be considered to be a Class I, Division I location that shall extend upward to a level ft above the floor.

34. Service conductors shall be considered outside of a building or other structure where installed under not less than in. of concrete beneath a building or other structure.

35. A compartment or chamber to which one or more air ducts are connected and that forms part of the air distribution system is a(n) .

36. All cables installed in agricultural buildings shall be secured within in. of each cabinet, box, or fitting.

37. Where field-installed wiring pass through an opening in an enclosure, conduit box, or barrier, a shall be used to protect the conductors from the edges of an opening having sharp edges within generators.

38. The service equipment shall be mounted in a readily from the accessible outdoor location, and mobile home it serves.

39. Any dwelling unit wall space ft or more in width (including space measured around corners) and unbroken along the floor line by doorways and similar

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45. Exposed vertical risers from industrial machinery shall be permitted to be supported at intervals not exceeding ft, provided the intermediate metal conduit is made up with threaded couplings, is securely supported at the top and bottom of the riser, and no other means of intermediate support is readily available.

46. Duty on elevator driving machine motors shall be rated as .

47. Continuous duty is an operation at a substantially constant load for .

48. Each Category I space patient bed location in a health branch care facility be shall supplied by at least cricuit(s).

49. A metal pole, supporting a luminaire, does not require a handhole if the pole is ft or less in height above grade where the supply wiring method continues without splice or pull point, and where the interior of the pole and any splices are accessible by removing the luminaire.

50.

For a one-family dwelling, at least one receptacle outlet readily accessible from grade and located not more than ft above grade level shall be installed at the front and back of the dwelling.

FINAL EXAM 1

ANSWERS

1. Answer: 20 Reference: 410.30(B)(1) Exception No. 2

19. Answer: main bonding jumper Reference: Article 100 (Bonding Jumper, Main)

2. Answer:

20. Answer: ¼ Reference: 314.20

7. Section 334.23 states that nonmetallic-sheathed cable installed in attics must comply with 320.23.

Reference: 320.23(A)

3. Answer: shall or shall not Reference: 90.5(A) 4. Answer: 1000 Reference: 110.16(B) 5. Answer: dry Reference: Article 100 (Location, Dry) 6. Answer: 24 Reference: 210.52(C)(1) 7. Answer: 5 Reference: 500.8(E)(1) 8. Answer: 115% Reference: 430.110(A) 9. Answer: 10 seconds Reference: 517.32(B) 10. Answer: 6 Reference: 250.102(E)(2) 11. Answer: 12 Reference: 410.16(D)(1) 12. Answer: 6 Reference: 392.30(B)(3) 13. Answer: 10 Reference: 210.52(H) 14. Answer: b) II only Reference: Article 100 (Bathroom) 15. Answer: 18, 20 Reference: Table 514.3(B)(1) 16. Answer: 6 AWG Reference: 334.15(C) 17. Answer: 70% Reference: 630.31(A)(1)

21. Answer: 8 Reference: 517.18(B)(1) 22. Answer: 15-ampere, lower Reference: 240.50(C) 23. Answer: 30 amperes Reference: 600.5(C)(1) 24. Answer: the width of the equipment Reference: 110.26(A)(2) 25. Answer: 18 Reference: Table 511.3(C) 26. Answer: 15 or 20 Reference: Table 210.21(B)(3) 27. Answer: Bonded or Bonding Reference: Article 100 (Bonded) 28. Answer: listed tamper-resistant receptacles Reference: 406.12 29. Answer: noncoincident Reference: 220.60 30. Answer: 125% Reference: 430.22 31. Answer: 5 Reference: 680.41(A) 32. Answer: permanent barriers Reference: 314.28(D) 33. Answer: 5 Reference: 517.60(A)(1) 34. Answer: 2 Reference: 230.6 35. Answer: plenum Reference: Article 100 (Plenum) 36. Answer: 8 Reference: 547.21

18. Answer: 3 Reference: 230.9(A)

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FINAL EXAM 1

ANSWERS continued

37. Answer: bushing Reference: 445.16 38. Answer: within sight Reference: 550.32(A) 39. Answer: 2 Reference: 210.52(A)(2)(1) 40. Answer: 5 Reference: 368.30 41. Answer: 8 Reference: 520.72 42. Answer: 150, 2 Reference: 220.46(B) 43. Answer: 5, 5 Reference: 513.3(C)(1) 44. Answer: 3 hours Reference: 450.42 45. Answer: 20 Reference: 342.30(B)(3) 46. Answer: intermittent Reference: 620.61(B)(1) 47. Answer: an indefinitely long time Reference: Article 100 (Duty, Continuous) 48. Answer: 2 Reference: 517.19(A) 49. Answer: 8 Reference: 410.30(B)(1) Exception No. 1 50. Answer: 6½ Reference: 210.52(E)(1)

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FINAL EXAM 2 1. Equipment that is visible and not more than distant from other equipment is that other equipment.

13.

2. Each operating room in a health care facility shall be provided with a minimum of receptacles.

14. Where a permanently installed swimming pool is installed, at least one 125-volt 15- or 20-ampere receptacle on a general-purpose branch circuit shall be located a minimum of ft from and not more than from the inside wall of the pool.

3. Electrical nonmetallic tubing shall not have more than the equivalent of four bends between pull points.

A grounded circuit conductor shall be permitted to be connected to non-current-carrying metal parts of equipment on the side of the ac servicedisconnecting means.

4.

In each conduit run leaving a Class I, Division 2 location, the sealing fitting shall be permitted to be installed on either side of the boundary within ft of the boundary.

15. In multiwire branch circuits, the continuity of a(n) shall not depend on device connections such as lampholders, receptacles, and so forth, where the removal of such devices would interrupt the continuity.

5.

The point of attachment of the overhead service conductors to a building shall not be less than ft above finish grade.

16. The NEC is not intended as a design specification or a(n) .

6. Nonmetallic-sheathed cable must be secured within in. from a single gang plastic device box (2¼ in. x 4 in.) mounted in a wall if the cable is not secured to the box.

7. The space equal to the width and depth of switchboards, panelboards, and motor control centers and extending from the floor to a height of ft above the equipment or to the structural ceiling, whichever is lower, shall be dedicated to the electrical installation.

8. On a 4-wire, delta-connected system where the midpoint of one phase winding is grounded, only the conductor or busbar having the higher phase voltage to ground shall be durably and permanently marked by an outer finish that is in color or by other effective means. is a conductor that ensures the required 9. A(n) electrical conductivity between metal parts that are required to be electrically connected.

10. For dwelling units, in each attached garage and in each detached garage with electric power, at least one receptacle outlet shall be installed in each vehicle bay and not more than ft above the floor.

11. The total rating of utilization equipment fastened in place, other than luminaires, shall not exceed percent of the branch-circuit ampere rating where lighting units, cord - and plug-connected utilization equipment not fastened in place, or both, are also supplied.

12. A surface-mounted fluorescent luminaire installed on the ceiling of a clothes closet must have a minimum clearance of in between the luminaire and the nearest point of the closet storage space.

17. A(n) is a device intended to provide protection from the effects of arc faults by recognizing characteristics unique to arcing and by functioning to de-energize the circuit when an arc fault is detected.

18. Panelboards shall be durably marked by the manufacturer with and the number of ac phases or dc buses for which they are designed and with the manufacturer’s name or trademark in such a manner so as to be visible after installation, without disturbing the interior parts or wiring.

19. Service-entrance cables shall be supported by straps or other approved means within 12 in. of every service head, gooseneck, or connection to a raceway or enclosure and at intervals not exceeding in.

20. The ampacity of capacitor circuit conductors shall not be less than of the rated current of the capacitor, if rated 1000 volts or less.

21. A(n) is defined as the connection between the grounded circuit conductor and the supply-side bonding jumper, or the equipment grounding conductor, or both, at a separately derived system.

22. If the vertical rise is greater than ft, 250 kcmil copper conductors in vertical raceways shall be supported.

23. Each patient bed location in a Category 1 space of a health care facility shall be provided with a minimum of receptacle(s).

24. For dewlling units, a receptacle outlet shall be installed at each kitchen countertop space that is in. or wider.

25.

Covers of outlet boxes and conduit bodies having holes through which flexible cord pendants may pass shall be provided with approved or shall have smooth, well-rounded surfaces on which the cord will bear.

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FINAL EXAM 2 continued 26. Internal parts of electrical equipment, including busbars, wiring terminals, insulators, and other surfaces, shall not be by foreign materials such as paint, plaster, cleaners, abrasives, or corrosive residues.

38. Sign or outline lighting system equipment shall be at least ft above areas accessible to vehicles unless protected from physical damage.

39. A continuous load is where the maximum current is expected to continue for .

27. Interior metal water piping that is electrically continuous with a metal underground water pipe electrode and is located not more than ft from the point of entrance to the building, as measured along the water piping, shall be permitted to extend the connection to the grounding electrode(s).

40. At least one receptacle outlet shall be located on a wall or partition that is to the sink or sink countertop, located on the countertop, or installed on the side or face of the sink cabinet in a dwelling unit bathroom.

28. In commercial garages, lamps and lampholders for fixed lighting that is located over lanes through which vehicles are commonly driven shall be located not less than ft above the floor level.

41. At a carnival, a means to disconnect each portable structure from all ungrounded conductors shall be provided, and the disconnecting means shall be located within sight of and within ft of the operator’s station.

29. Circuit conductors between the final overcurrent device protecting the circuit and the outlet(s) is called a(n) .

30. In any anesthetizing area of a health care facility, all metal raceways and metal-sheathed cables, and all normally non-current-carrying conductive portions of fixed electric equipment, shall be .

31. A single piece of equipment consisting of a multiple receptacle comprised of four or more receptacles shall be calculated at not less than per receptacle.

32. All fixed metal parts that are within ft horizontally of the inside walls of a permanently installed swimming pool, and within ft above the pool’s maximum water level shall be bonded together.

33. In both exposed and concealed locations, where a cable- or raceway-type wiring method is installed through bored holes in joists, rafters, or wood members, holes shall be bored so that the edge of the hole is not less than in. from the edges of the wood member.

34. Receptacle outlets installed in a dwelling unit for specific appliances, such as laundry equipment, shall be installed within ft of the intended location of the appliance.

35. Outdoor mobile home disconnecting means shall be installed so the center of the grip of the operating handle, when in the highest position, is not more than ft in. above the finished grade or working platform.

36. Circuit breakers shall be marked with their ampere rating in a manner that will be after installation.

37. A door sill or curb that is of an approved height that will confine the oil from the largest transformer within the vault shall be provided, and in no case shall the height be less than in.

40

42.

Ground-fault protection of equipment shall be provided for solidly grounded wye electric services of more than 150 volts to ground, but not exceeding 1000 volts phase-to-phase for each service disconnect rated or more.

43. Flexible cords shall be secured to the undersides of showcases so that a separation between cases not in excess of in., or more than in. between the first case and the supply receptacle, will be ensured.

44. A(n) is a structure designed to support a wetniche luminaire assembly and intended for mounting in a pool or fountain structure.

45. If multiple ground rods are installed for the grounding electrode system, they shall not be less than _____ ft apart.

46. Generally, receptacles in dwelling units shall be so installed so that no point measured horizontally along the floor line of any wall space is more than ft from a receptacle outlet.

47. Shore power for boats shall be provided by single receptacles rated not less than amperes.

48. Aircraft energizers shall be designed and mounted such that all electric equipment and fixed wiring will be at least in. above floor level.

49. Unless otherwise permitted, Type AC cable shall be supported and secured at intervals not exceeding _____ ft.

50. The life safety branch and equipment branches in a hospital shall be installed and connected to the alternate source of power so that all specified functions for the life safety and equipment branches are automatically restored to operation within ________ seconds after the interruption of the normal source.

FINAL EXAM 2

ANSWERS

1. Answer: 50, in sight from Reference: Article 100 (In Sight From) 2. Answer: 36 Reference: 517.19(C)(1) 3. Answer: quarter, ¼, or 90° Reference: 362.24(B).

4. Answer: 10 Reference: 501.15(B)(2) 5. Answer: 10 Reference: 230.26 6. Answer: 8 Reference: 314.17(B)(2) Exception 7. Answer: 6 Reference: 110.26(E)(1)(a) 8. Answer: orange Reference: 110.15 9. Answer: bonding conductor Reference: Article 100 (Bonding Conductor) 10. Answer: 5½ Reference: 210.52(G)(1) 11. Answer: 50 Reference: 210.23(B)(2) 12. Answer: 6 Reference: 410.16(D)(2) 13. Answer: supply Reference: 250.142(A)

19. Answer: 30 Reference: 230.51(A) 20. Answer: 135% Reference: 460.8(A) 21. Answer: System bonding jumper Reference: Article 100 (Bonding Jumper, System) 22. Answer: 60 Reference: Table 300.19(A) 23. Answer: 14 Reference: 517.19(B)(1) 24. Answer: 12 Reference: 210.52(C) 25. Answer: bushings Reference: 314.102 26. Answer: damaged or contaminated Reference: 110.12(B) 27. Answer: 5 Reference: 250.68(C)(1) 28. Answer: 12 Reference: 511.7(B)(1)(b) 29. Answer: branch-circuit Reference: Article 100 (Branch-Circuit) 30. Answer:

connected to an equipment grounding conductor Reference: 517.62

14. Answer: 6, 20 Reference: 680.22(A)(1)

31. Answer: 90 volt-amperes Reference: 220.14(I)

15. Answer: grounded conductor Reference: 300.13(B)

32. Answer: 5, 12 Reference: 680.26(B)(7)

16. Answer:

33. Answer: 1¼ Reference: 300.4(A)(1)

instruction manual for untrained persons Reference: 90.2(A)

17. Answer: Arc-Fault Circuit Interrupter Reference: Article 100 (Arc-Fault Circuit Interrupter) 18. Answer: the voltage and the current rating Reference: 408.58

34. Answer: 6 Reference: 210.50(C) 35. Answer: 6, 7 Reference: 550.32(F) 36. Answer: durable and visible Reference: 240.83(A)

41

FINAL EXAM 2

ANSWERS continued

37. Answer: 4 Reference: 450.43(B) 38. Answer: 14 Reference: 600.9(A) 39. Answer: 3 hours or more Reference: Article 100 (Continuous Load) 40. Answer: adjacent Reference: 210.52(D) 41. Answer: 6 Reference: 525.21(A) 42. Answer: 1000 amperes Reference: 230.95 43. Answer: 2, 12 Reference: 410.59(C) 44. Answer: forming shell Reference: Article 100 (Forming Shell) 45. Answer: 6 Reference: 250.53(A)(3) 46. Answer: 6 Reference: 210.52(A)(1) 47. Answer: 30 Reference: 555.33(A)(4) 48. Answer: 18 Reference: 513.10(C)(1) 49. Answer: 4½ Reference: 320.30(B) and (C) 50. Answer: 10 Reference: 517.43

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