how to derive tcc for oil cb with dashpot, wh f-124

[1one1]

thread238-280767

does somebody have tcc for Westinghouse Type F-124-A Oil Circuit-Breaker?

also, in case that there is not one, how can it be derived? both for cb and the dashpot.

is this cb similar to any of the ge ec type ak-15,25,50,75

cb manual

http://www.electricalpartmanuals.co...use/Insulated Case Breakers/I.B.33-266-2A.pdf

http://www.homewoodsales.com/PDFs/t...ng-Mechanism-for-Type-F-122-and-F-124-Oil.pdf

http://www.homewoodsales.com/PDFs/t....B.-33-216/Type-SAF-2-Operating-Mechanism.pdf

 

[unclebob]

Hmm, this is not a low voltage breaker! These come with separate protection relays, (ex.: Westinghouse CO type induction disk) not integrated trip units, electromechanical or electronic.

http://www.electricalpartmanuals.co...ghouse/Insulated Case Breakers/D.B.33-150.pdf

 

[oldfieldguy]

This is not equivalent to the GE "AK" series, which are low-voltage breakers.

The first manual you attach shows the dashpot installation.

Assuming that the dashpot is still filled with good oil of the proper density (and it has been a long time since I've seen dashpot oil), you can do current injection to determine points on a trip curve. If you have some idea of the full current ratings, then a few tests at 200, 300 and 500% will give you some idea of the time-overcurrent characteristic.

Remember, these were never meant to be precision devices, so abandon the ideas of accuracy you're used to seeing with digital relays, or for that matter, properly maintained induction disk relays.

Further, the contact parting and clearing times are likely to be much different than the 2-3 cycles of modern circuit breakers.

With a lot of care, this equipment can be made serviceable after a fashion.

If I had to think about putting this thing into service, I'd be trying to figure out a way to upgrade.

old field guy