Elevator Shunt Trip Operating Power

[flengineer]

Does the 120V feed for an elevator's shunt trip operating power need to be fed from a dedicated circuit? Is it considered utilization equipment per 620.55 or can I use the machine room lighting/receptacle circuit for power for the shunt trip?

 

[chris kennedy]

I'm going to bump this thread as I find it quite refreshing an engineer in my area would ask this question. Where to pick up power for the elevator shunt is something constantly missed on the E and FA pages around here. I always defer to the F/A contractor as to where to pick up power as he is the NFPA 72 expert and it is his ultimate responsibility to pass the fire inspections.

In the following install the shunt trip AC voltage is monitored by the F/A system and I had plenty of available breaker spaces. Circuit 30 is the system power and 32 is the elevator shunt.

You could also direct your question here.

Sorry about the bad pic.

 

[nakulak]

In the last couple elevators I did (maryland) I brought a neutral to the elev disco and tapped one of the phases , fused it and used it for shunt trip. nobody objected to it, and it occurred to me that it might actually be safer than providing an alternate source, since the elevator shunt trip operation was pretty much guaranteed if the elevator was operating, but I didn't know if it might be some kind of technical violation (still don't) (especially since the elevator codes seem to always be ANSI, and not something I have studied)

 

[tobacmon]

Shunt Trip for Elevators

Shunt Trip for Elevators

We have a shunt trip that was installed my guess back in 94-95 and were told by our local inspection that it needed to be on a seperate cicuit and tagged out and not on a lighting circuit if memory serves me correctly. Can you tell me if I post a picture or pictures if this is done correctly?

 

[steve66]

Yes, I think engineers try not to specify where the power comes from because they aren't sure where it should come from. I'm never sure either.

BTW, the code requires monitoring of this power.

I would not take it from the machine room lights/receptacles. I think that's supposed to be a dedicated circuit. I do like the idea of deriving it from the elevator power.

I'm never sure how to handle making sure the elevator makes it to the recall landing before we trip the power.

This is something engineers have to design themselves, when, in my opinion, this is something that should be standardized. I'm refering to the entire elevator/fire alarm/shunt trip power/shunt trip monitoring ball of wax. We draw something up on paper without really knowing any details about the elevator control panel, or the fire alarm panel. If the shunt trip is tested at all, it is tested once at startup and that it.

It just seems like all the functions that are needed for this should be part of the fire alarm system, or maybe part of the elevator control panel. It should part of a tested and listed package. Not something that we force every electrical engineer to design from scratch.

Steve