Hey guys, I'm having a problem that I just can't figure out. We have a fairly new 5kV switchgear lineup from Powell. We had the whole thing site tested to NETA standards back in April and everything was fine. One feeder wasn't ready so we didn't energize it until last week... when we closed the breaker, all the relays and lights shut off, only to come back on a few seconds later! Through doing it a few times, we figured out that once the breaker closes and the charging motor starts up, the voltage on the 125VDC control circuit (fed from a charger and battery stack) is dipping severely up until the point that the spring is charged, then it goes back up to 125VDC. The next time, we watched the screen on the charger... the voltage went from 125VDC to 10, then 7, then 3, then as soon as the motor was wound up, went right back to 125VDC. We figured it was something with the motor (either a resistive short or a partially seized shaft), so we took the breaker out and put in a spare we had... exact same thing!! Does anyone have any ideas??
Thanks
Thanks