ACS800 trip due to Earth fault F2330
IGBT Diode Test and Value.
1. DC+/- ------ VSD Output U Phase = 0.323 V DC
2. DC+/- ------ VSD Output V Phase = 0.322 V DC
3. DC+/- ------ VSD Output W Phase = 0.323 V DC
using multi meter to confirm the value. after we check Motor side using megger value and confirmed no short-circuit. reset and change DTC to Scalar mode (remove Motor cable from motor ) and run the VSD in manual mode ( SS switch change position ) using ABB Operator panel VSD running fine and check output voltage ok no trip happened during testing.
after we connect the cable and change the control mode Scalar to DTC and start from our controller compressor VSD running fine. output current all ok. compressor running around 15 to 20 minutes after compressor trip due to over current F2310 and reset the fault and start back again trip due to Short- circuit F2340. after many start trip with same fault like F2340.
again we power off and test the diode value this time we found the all three phase diode value is 0.001 and confirm IGBT short. customer really very unhappy because new VSD only running 20 months after failure. last year June 2018 the VSD repaired by abb under warranty due to earth fault problem F2330. the same problem start again last week (June 2019 )we went site and check the motor side to confirm no short circuit. the motor winding insulation was more than 2000 meg ohms. customer really unhappy and they not accept this issue.
For temporary solution we change Earth fault trip to warning now compressor running.
ABB VFD Serial Number- 1154503120.
what is the permanent solution on this issue how to prevent this problem in future.
I am very sorry for your customer and for the inconveniences that I imagine will have suffered. For cases like the one you reported, the best solution is to involve the ABB service, which can provide all the support you need in your case.
With all the good will, I don't believe that someone from the forum can help you, especially because we are not able to see the drive on which the problem occurs.