Frequently asked questions
What is an USF fault on the ATV28 drive?
FA177899
18 March 2022
Issue:
ATV28 USF fault.
Product Line:
Altivar ATV28
Environment:
All
Cause:
Mains undervoltage is to low on L1 L2 L3.
Resolution:
USF is an undervoltage fault.
Check the Mains voltage on L1 L2 L3 with a digital meter.
Check the DC bus voltage on PA and PC