Wondering if anyone could give me some insight. I have two new Abb drives (ACH 550's) on a 6 month old cooling tower. The motors are 10 hp 460 volt, I keep getting a fault code of 16 (Earth ground Fault) I have megged the motors out both motors megged above 700 megaohms, when I say both yes I have issues with both drives on the tower. They might run two weeks then fault out, they might run two days then fault out. I called ABB and was told there must be moister in the motor, and to meg out this would tell me. From what I have looked at and tested I have found no moister. From the drive to the motors on the tower is approx 100 to 150' ft run of wire, I have also been told there is a chance of capacitance build up in the wire,. If so would a load reactor help my issue. For what it is worth we have another tower that was replace about a year ago and I had the same issue with the motors on that tower for about a month, after it was started but the problem went away and has not come back.
Any feed back would be greatly appreciated
Thanks,