Load current unbalance cause of trip?
Load current unbalance cause of trip?
(OP)
We had an interesting trip the other day. A squirrel got across a normally open tie air break switch between two 13.8kV feeders. Both station breakers tripped correctly, but a downstream recloser on one of the circuits also tripped on ground for some reason. There is no known ground source beyond that recloser. I attached the fault record from the recloser, which also shows the one-line. One thing I notice is that there is a fair amount of load current unbalance on that circuit. Do you think that could have accounted for the ground current shown in the fault record? Unfortunately we don't have PTs on that recloser so I don't know what the voltages looked like.
Thanks,
Sean
Thanks,
Sean






RE: Load current unbalance cause of trip?
RE: Load current unbalance cause of trip?
If you're curious, attached is a fault record from another recloser which had a 3-167kVA, 13.8 kV wye / 4.8 kV delta connected bank downstream from it. The fault was before the recloser in that case as well.