SOLVED!! Thank you for your input.
We did tried couple of times to increase the TD and trip setting.
Below shows our trial and error.
10A 50ms - trip
20A 50ms - trip
20A 100ms - trip
30A 100ms - trip
40A 100ms - OK both motors running.
We found the CBCT IN goes to max of 34A which explains the...
Hi dpc, current varies from 10A to 30A in CBCT.
If sum all phases, it doesn't add up to be the same. We suspect the CBCT and will try to change today.
Trip is while starting - 10ms, 20ms and 30ms during starting depends on the time delay set.
Yes, CT programmed correctly 50:5.
SEL terminalogy -...
Hey Guys.
We are commissioning 2 4000HP motors via 4KV controlgear. The issue we are facing is that both motors keep tripping during commissioning performing motor solo run. They are both tripping on 50N Ground Fault via SEL-710 relay. Ground fault current detected via CBCT 50:5. The setting...