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Ground fault on AC Tech SC450 Drive

Ground fault on AC Tech SC450 Drive

Ground fault on AC Tech SC450 Drive


We are currently using a AC Tech SF450 VFD to drive a 5HP conveyor brush motor. We have been having recurring "UF" faults that basically renders the drives useless. A quick troubleshot suggests the fault is a result of a ground fault. Any thoughts on avoiding ground faults on a VFD Drive? Should we be using a different drive? One that has an inbuilt ground fault protection? Please advice.

RE: Ground fault on AC Tech SC450 Drive

By "conveyor brush motor" I assume that you mean a motor that is driving a brush on a conveyor, not a conveyor motor that uses brushes inside of the the motor.

On that VFD, the "UF" fault code simply means you are giving the drive a Run command before the drive has finished powering up. You must wait at least 2 seconds after applying power to give the VFD a Run command. Some brands of drives allow you to close the Run command prior to applying power, this is not one of those.

" We are all here on earth to help others; what on earth the others are here for I don't know." -- W. H. Auden

RE: Ground fault on AC Tech SC450 Drive

Thank you for the feedback @jraef. You are right in saying it is a Motor that is driving a brush under a conveyor belt. So does the UF fault renders the VFD defective? Which brands would be recommend?

RE: Ground fault on AC Tech SC450 Drive

Try a delay on your run command when you power up the drive.
Do not power up the drive with the run command active.

"Why not the best?"
Jimmy Carter

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