ECN Forum Forums General Topics of the Trade General Discussion Area stored energy breakers

Is it ok to leave stored energy breaker in the charged position?We had a power factor correction cap catch fire on an Mcc and when i went to close the distrobution breaker i found that it was aready charged and must have been that way since Seimans racked it months ago?personaly i always leave them discharged once closed.
thanks

I can't say if it's good or bad but insulated case breakers with motor operators recharge themselves right after they close by design. The springs stay charged until the breaker needs to close again.

Drawout circuit breakers with charging motors should have a spring discharge interlock so the closing springs are discharged automaticly when they are racked out. I dont see any other hazard of leaving the springs charged.

After a breaker is closed the "spring" can be recharged without a problem. A breaker will always trip no matter if you have charged the spring or not. If you choose to recharge the spring after closing the breaker the beaker can be tripped, reclosed, and tripped again. After that you have to recharge the spring to close the breaker again.
A motor operator will always keep the spring charged instead of you doing it manually.
Bottom line is don't worry about it and simply keep the spring recharged as most commonly do.

Can any of ya'll provide me with a quick description or a link to a comprehensive source that describes what "stored energy breakers" are? I've never heard of them before but from what I read here I have a suspicion they might be similar to those large breakers in switchgear cabinets that have to be "pumped" several times before they can be closed. Is that close?

Thanks.

-John

BigJohn,yes we are talking about the same device exactly.I'm not 100% sure I'm calling it by the right name either so...
Dave T,I imagine if the breaker is left charged and then discharged while already closed it's not a problem?It just seems that there is less confusion if its discharged.
In this instance the the open/close flag had spun past the veiwing window so you could see inside the breaker as well.

[This message has been edited by frank (edited 09-19-2005).]

The correct terminology would be a drawout low voltage power circuit breaker with a motor charged-spring operated mechinism.

Because these breaker require such high energy springs to close the contacts you would have a manual charging handle that must be operated numerous times in a ratcheting movement, pumped, to charge the spring. It can not be done in one motion like would be cone with a common industrial breaker. I don't know how many out there have had the privilege of closing a 2500a frame industrial molded case circuit breaker but it's very difficult if you don't have that handle extension installed.
So on both LV power and MV breakers they are designed such that you use a ratcheting movement to wind the spring then close the breaker with a simple push of a button.
These breakers can be closed electrically with a spring release solenoid and opened remotely with a shunt trip. The motor operated is added to recharge the spring when it discharges so that you don’t have to.