F091 fault in WEG CFW900 Drive indicates an External Protection fault. This means a peripheral safety device connected to the digital inputs has opened, forcing the drive to shut down safely.
Cause:
External fault via digital input.
- DI input wiring programmed to generate external faults is open.
Note: Necessary to set the DI in parameter C7.10.2.
Remedy:
Check digital input terminal loops and ensure external switches are not triggering open circuits.
