Cause : Unknown PU fault comes when unidentified power unit logic fault. This fault code signifies the drive detected an issue it can't pinpoint to a specific reason.

An "unidentified power unit logic fault" in your ABB ACS880 drive indicates a problem within the Power Unit's (PU) internal logic circuits. The PU is a critical component responsible for managing power flow and control in the drive.

• Check the logic and firmware compatibility.