Kohler Ronan Consulting Engineers - KR Vision Newsletter - Issue 8, Fall 2018

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VISION ISSUE EIGHT | FALL 2018

Fire Protection Within Hydraulic and Traction Elevators There are two major types of elevators: hydraulic and traction. The hydraulic elevator utilizes a piston which telescopes and pushes the elevator upwards. The length of this piston limits the number of floors that the elevator can serve, as well as its speed. Hydraulic elevators tend to operate slower than traction elevators, in fact, both geared and gearless traction elevators can reach greater heights and faster speeds than their hydraulic counterparts. Traction elevators utilize sheaves, steel cables, and a counter weight. Control System Geared Machine Primary Velocity Transducer Governor Hoisting Ropes Roller Guides Secondary Position Transducer Door Operator Entrance-Protection System Load-Weighing Transducers Car Safety Device Traveling Cable

Piston

Fluid Tank/ Controller

Elevator Rail Counterweight Compensation Ropes Governor Tension Sheave Counterweight Buffer Car Buffer

Traction Elevator

Two Car Buffers In-Ground Cylinder

Hydraulic Elevator

Historically, elevators have required that a machine room house the hydraulic motor, fluids, and/or controls. Today, some traction elevators are considered “machine room less” meaning that the square footage traditionally required for a machine room is no longer needed. The biggest benefit of the machine-room-less elevator is evidently the space gained which then may be devoted to other uses. Protection of elevator hoistways (shafts) and elevator machine rooms are governed by local building and fire codes, including NFPA 13, 72, and ASME A17.1 (Safety Code for Elevators and Escalators). Elevators can be protected by several devices

including fire sprinklers, smoke detectors, heat detectors, and louvers. Fire Sprinklers Fire sprinkler requirements are outlined in NFPA 13. Essentially, automatic sprinklers in elevator machine rooms, or at the top of hoistways, must be of an ordinary or intermediate temperature rating. Top of the Shaft Upright, pendent, or sidewall sprinklers shall be installed at the top of elevator hoistways. Exception: The sprinkler required at the top of the elevator hoistway shall not be required where the hoistway for passenger elevators is noncombustible and the car enclosure materials meet the requirements of ASME A17.1, Safety Code for Elevators and Escalators. Bottom of the Shaft Sidewall spray sprinklers shall be installed at the bottom of each elevator hoistway not more than 2 ft. (0.61 m) above the floor of the pit. Exception: The sprinkler required at the bottom of the elevator hoistway shall not be required for enclosed, noncombustible elevator shafts that do not contain combustible hydraulic fluids. Other Sprinklers shall be installed at the top and bottom of elevator hoistways where elevators utilize polyurethane-coated steel belts or other similar combustible belt material. The omission for fire sprinklers is allowed in passenger elevators only; there are no exceptions to fire sprinkler requirements for freight elevators. Smoke Detection Smoke detection is required within ALL TEXT ©2018 KOHLER RONAN, LLC

the elevator shaft, elevator machine room, and at each floor level of each elevator in accordance with ASME A17.1. Should smoke be detected at any of these locations, the elevator would immediately “recall” to the predetermined floor, allow the passengers to exit, and lock out the use of the elevator. For lay people, firefighters may be able to override the system. Should smoke be detected at the “pre-determined” floor, the elevator would respond and open at an alternate, preprogrammed floor level. In general, smoke detection initiates elevator recall. If sprinkler heads are not installed, smoke detection within the shaft is not allowed; however, the local Authority Having Jurisdiction (AHJ) should be consulted. MACHINE ROOM OVERRIDE

OVERRIDE

CAR CAR

CTRL ROOM

LANDING

LANDING

LANDING

LANDING

LANDING

LANDING PIT

Traction Elevator

PIT

Machine Room-less Elevator

Heat Detection If fire sprinklers are required at either the top or bottom of the elevator shaft, a heat detector is also required within 24” of each fire sprinkler head. This heat detector shall have both a lower rating and continued on page 4

IN THIS ISSUE Lighting Control 2 Got Steam? Revit® Corner

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On the Boards

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