Shunt Trip Breaker

k-911

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!

mdshunk

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):

Perhaps user SpeedyPetey will add additional comments, since he's a former big-city electrician and has probably wired up his share of elevators.

mdshunk

I thought that I should add that if your building is not sprinklered, that also frees you from the shunt trip requirement 2.8.2.3.2 of ASME A17.1

k-911

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

mdshunk

Oh, stop it.

OSPA

Is it requred to have it monitored by fire alarm?

Magnettica

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Electric_Light

Elevators carry passengers and its code requirements are justifiably unique and different from traditional electrical requirements.

YCI

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

jmiley

In Florida they are, not sure about other area's.