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Shunt Trip

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dlabrie4

New User
Location
Oak Harbor Washington
Occupation
Maintenance Electrician
I have a elevator shunt trip breaker that the output relay wiring has been capped off and not reporting anything back to the FACP. The shunt trip relay on the breaker will trip the breaker when tripped by the detector, but not report to the FACP. This shunt trip is located in the elevator mechanical room. The room has a heat detector that does report to the FACP and a Heat detector for the shunt trip. When the shunt trip is trip our elevator does not lower to any floor, trapping the occupants.
My question is how should the double pole relay wired to the elevator battery lowering device and FACP when we purchase one?
Any diagram is appreciated.
I have a GE cat no. SELA36AT0100 breaker.
 
Welcome to the forum.

Others will follow, but I think you really, really need to get the elevator service people involved.

This is life safety stuff.
 
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To be sure I understand, the shunt trip breaker has an auxiliary relay with form A, B, or C contacts so the change of state can be exported to a foreign system? This aux relay has wiring coming out but capped, and therefore the fire alarm control unit (FACU) does not receive an input when the relay is tripped?

There is no requirement in NFPA 72 to report back the state of the shunt trip breaker for elevator service when activated. If you wish, you could use the output and tie it into a monitor module and report the status to the FACU.

When activated, the shunt trip relay halts the elevator wherever it is in the hoistway. This is absolutely normal operation. It's late, but I can go into greater detail on why lowering the car is difficult in a later post.
 
Usually the shunt trip is delayed in the elevator controls until the elevator is stopped and opened at the first, or nearest floor depending on the programming. It should never trip until that condition is met. But all of that is done by the elevator tech. All we do is supply the inputs, and they interlock the shunt trip.
 
hillbilly1 said:
Usually the shunt trip is delayed in the elevator controls until the elevator is stopped and opened at the first, or nearest floor depending on the programming. It should never trip until that condition is met. But all of that is done by the elevator tech. All we do is supply the inputs, and they interlock the shunt trip.
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The problem is that the shunt, in my experience, never goes through the elevator controller. The most common scenario you'll find the shunt operating is when the firemen use their key to take control. The normal elevator control is now out of the loop; it's all manual by the firemen. When the heat detector is activated, it trips an addressable fire alarm relay in the field and that relay is the switch that puts voltage on the coil of the shunt trip. No elevator controller interface is involved.

Maybe there are elevator controllers out there that do control the shunt operation. If firemen are on a floor holding the door open, what do you think should happen? Have the elevator force the doors closed, possibly trapping the firemen on a fire floor? I'm not sure I want to write that programming for the controller. It's messy any way you look at it, and it all revolves around firemen having control of the elevator. In the usual fire case, the elevator returns to the primary or alternate recall floor, the doors open and that's it. Now if it gets hot enough in the hoistway to activate the heat detector and the shunt operates there's no problem. It's that space in between, where firemen put the elevator into fire service mode that presents an opportunity for bad things to happen.
 
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