ABB ACQ580 75hp 3ph 3 wire Delta 480V

[Dale87]

Abb acq580 75hp on a deep well pump. 500' of motor leads, 110A TCI V1000 output reactor/filter on drive output leads . Service is a 3 phase 3wire Delta 480 volt. All equipment installed in last 8 months, clean temp controlled environment. Output reactor sounds like it's got a delamination in the core or something, sounds terrible, smells terrible, current on motor is fine and balanced. Drive dc bus voltage is fine. Output voltage is fine except b phase output is 30 volts to ground on the drive. A and C are 400volts to ground. Wild voltage fluctuations from all phases to ground on mcc bus when this VFD is running. I understand it's a 3 wire Delta but I've never seen such swings....from 100-400 volts fluctuating every second. I've had ground faults in 3 wire deltas before and ground a phase but nothing like this. Could it be an arcing fault in that reactor intermittently grounding a phase? Will a VFD pick up a ground faults on it's outputs on a Delta 3 wire bank? Don't know if the mov screws are in or out. Anyone got any ideas? System is not corner grounded either fyi.

 

[cottagewood]

My first observation would be, has this just started or has it had a problem since first installation?
Is there another installation there that you can compare it to?
Could it be losing a phase somewhere to the drive input?
There is a section in the manual warning of the compatibility of the supply system with clear diagrams and solutions, have you checked that? IÂ’m guessing you have as you already checked itÂ’s not corner grounded.
I assume the motor cables are shielded, is the shield and the earth connected directly at the inverter?
Is it running in Scalar or Vector control? If its Vector itÂ’s essential that the exact motor details have been entered and the ID run has been done.

 

[Dale87]

My first observation would be, has this just started or has it had a problem since first installation?
Is there another installation there that you can compare it to?
Could it be losing a phase somewhere to the drive input?
There is a section in the manual warning of the compatibility of the supply system with clear diagrams and solutions, have you checked that? IÂ’m guessing you have as you already checked itÂ’s not corner grounded.
I assume the motor cables are shielded, is the shield and the earth connected directly at the inverter?
Is it running in Scalar or Vector control? If its Vector itÂ’s essential that the exact motor details have been entered and the ID run has been done.

Motor leads wouldn't meg. Ended up being a conductor shorted to ground at the well head. Interesting fact i guess i never realized, a drive won't see a ground fault on a Delta 3 wire service, makes since, how would it without a ground reference. Also a ground fault on the load side of a drive won't show up on grounding lights either. If it wasn't for the load reactor, id imagine the arcing fault would have wiped out the drive.

 

[RET]

Motor leads wouldn't meg. Ended up being a conductor shorted to ground at the well head. Interesting fact i guess i never realized, a drive won't see a ground fault on a Delta 3 wire service, makes since, how would it without a ground reference. Also a ground fault on the load side of a drive won't show up on grounding lights either. If it wasn't for the load reactor, id imagine the arcing fault would have wiped out the drive.

Or killed somebody.