Monday, we had a VFD that controls the spped of a conveyor belt fail on us. Took the replacement out of the box, installed it and bam, it failed, too.
While waiting for a replacement, we meggered the motor and it was fine. To double-check, we brought it to a local moitor shop for testing. Changed the whip from disconnect to motor. Meggered everything from VFD output all all tested OK. There's a load reactor after the VFD
Today, we installed a replacement and it fried when power was applied. Even blew the fuse
Legs are roughly equal - 576, 580 & 588 volts
Any suggestions? The only thing I can think of is a bad local disconnect, but that seems unlikely
While waiting for a replacement, we meggered the motor and it was fine. To double-check, we brought it to a local moitor shop for testing. Changed the whip from disconnect to motor. Meggered everything from VFD output all all tested OK. There's a load reactor after the VFD
Today, we installed a replacement and it fried when power was applied. Even blew the fuse
Legs are roughly equal - 576, 580 & 588 volts
Any suggestions? The only thing I can think of is a bad local disconnect, but that seems unlikely