FA237689
21 October 2022
Issue:USF fault on ATV61/71.
Product Line:All drives.
Environment:All.
Causes:Low voltage on drive's DC bus.
Resolution:USF is a mains undervoltage fault that appears when the drive's DC bus goes below a certain value.
Check the Mains voltage on L1, L2, and L3 with a true RMS meter.
Measure DC voltage on drive's DC bus PA (+) and PC(-) with meter.
