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Are shunt trip breakers required by code on all commercial elevators? My GC is installing a two floor commercial elevator, 240 volt single phase and said no shunt trip needed. I don't think so! Any thoughts!
 

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k-911 said:
Are shunt trip breakers required by code on all commercial elevators? My GC is installing a two floor commercial elevator, 240 volt single phase and said no shunt trip needed. I don't think so! Any thoughts!
Elevator shutdown, frequently referred to as shunt trip, is intended to immediately stop elevators before water from elevator machine room or hoistway sprinklers affects brakes and electrical equipment. Both wet brakes and wet electrical equipment can cause erratic life threatening elevator operation. Therefore, it is required by Requirement 2.8.2.3.2 of ASME A17.1 (Safety Code for Elevators, Escalators and Moving Walks) to "cause disconnection of the main line power supply upon or prior to the application of water from sprinklers in the machine room or hoistway". This occurs even if the elevator car is occupied and not at a landing. Oddly, this has the effect of potentially trapping occupants between floors in an elevator during a fire.

You'd have to check with your prevailing state or local elevator codes. There is nothing in the NEC that requires a shunt trip. Be advised that if you do use a shunt trip to comply with either local codes or ASME A17.1, you are NOT PERMITTED by the NEC to have this shunt trip disconnect power to the machine room lighting, car lighting and HVAC, and hoisway/pit lighting. Oddly again, the NEC does permit you to disconnect door control power, so people can be trapped in the elevator.

I advise you to hunt down the local prevailing elevator code, because you may have amendments and the GC might be right. Often, states have amended Requirement 2.8.2.3.3 of A17.1 to exempt HYDRAULIC elevators (not traction elevators) that rise 50 feet or less from the shunt trip requirement. Here's what the NEC says about the elevator's disconnecting means (read especially 620.51(B) which says that the shunt trip is permitted when used by the sprinkler system, but it doesn't say required. The Elevator and Escalator Safety Code does require it, not the NEC):

VI. Disconnecting Means and Control
620.51 Disconnecting Means. A single means for disconnecting
all ungrounded main power supply conductors for
each unit shall be provided and be designed so that no pole
can be operated independently. Where multiple driving machines
are connected to a single elevator, escalator, moving
walk, or pumping unit, there shall be one disconnecting
means to disconnect the motor(s) and control valve operating
magnets.
The disconnecting means for the main power supply
conductors shall not disconnect the branch circuit required
in 620.22, 620.23, and 620.24.
(A) Type. The disconnecting means shall be an enclosed
externally operable fused motor circuit switch or circuit
breaker capable of being locked in the open position. The
disconnecting means shall be a listed device.
FPN: For additional information, see ASME/ANSI A17.1-
2000, Safety Code for Elevators and Escalators.
Exception: Where an individual branch circuit supplies a
wheelchair lift, the disconnecting means required by
620.51(C)(4) shall be permitted to comply with 430.109(C).
This disconnecting means shall be listed and shall be capable
of being locked in the open position.
(B) Operation. No provision shall be made to open or
close this disconnecting means from any other part of the
premises. If sprinklers are installed in hoistways, machine
rooms, control rooms, machinery spaces, or control spaces,
the disconnecting means shall be permitted to automatically
open the power supply to the affected elevator(s) prior to
the application of water. No provision shall be made to
automatically close this disconnecting means. Power shall
only be restored by manual means.
Perhaps user SpeedyPetey will add additional comments, since he's a former big-city electrician and has probably wired up his share of elevators.
 

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Discussion Starter #4
MD, thanks for responding.I was hopping you would respond as you seem to have all the answers and are willing to share. Thanks.
 

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I was under the impression shunt trip are required when the building is sprinkled. If the building is not, shunt trip are not required.
 
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