DanDel, The CB did not flash externally and there was no fault down stream. The CB feeds a 1250HP mill motor. When the CB failed, the incomer tripped on earth fault, as this was seen as a busbar fault. Insulation tests were done on incomers, busbar and feeders, that is how this particular...
DanDel,
You guessed right. Our minds were in some kind of auto pilot: "Something has mechanically gone wrong with this CB, lets open it and check what we shall find."
We took the gas out and opened the tank only to find a flash and a general layer of carbon. Mechanically, the...
Thanks to you guys, DanDel, Rocketir and busbar.
DanDel - We confirmed that the tank had SF6 by checking the tank gas pressure before removing the gas from the tank to enable us gain access to the CB contacts.
busbar - I have sent a querry to ACTI. I'm yet to hear from them. Thanks.
The CB...
I have jus had an 11kV SF6 Circuit Breaker flash on our plant in a manner that suggests that either there was loss of SF6 the quality of th gas had deteriorated therefore loosing some of its critical properties. Because the tests showed that there was no loss of SF6 I would like to assume that...
