- Location
- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
If the drive electronics tripped in OL, it would not ramp up, it would show the fault. If there was a bypass, I would have HOPED that the OP would have mentioned that… But that’s a good point. If there was a bypass, the VFD output would be isolated from the motor leads and be exactly the same as having an open circuit. Then if that bypass starter was tripped in OL, nothing would be happening.Jraef,
I know this is old and the OP is long gone but is it possible that the overload tripped either in the drive or if it has one in the bypass assembly? I would imagine it would throw an alarm but I'm not sure, particularly if it was in the bypass section.
It also occurred to me that in days gone by, ABB drives used to have a feature called “Base Block” which shunted the base emitter to the transistors, immediately disabling them. Other drive mfrs do the same thing, calling it an “enable” circuit and it required a jumper between two terminals to allow the drive to function. Maybe that jumper came out or was removed by someone who didn’t realize what it was. Usually though the drive gives you some sort of error code indicating that it has been disabled, but the the ABB ACS355 is an “entry level” drive so maybe not? Who knows.