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.