F011 fault in WEG CFW900 Drive indicates Rectifier Overtemperature. This means the input rectifier modules have exceeded their safe thermal limits and the drive has tripped to prevent hardware damage.
Cause:
- High ambient temperature around the inverter (> 50 °C) and high output current.
- Blocked or defective cooling fan.
- Inverter heatsink is too dirty, preventing proper cooling airflow.
Remedy:
Verify fan operation and clean heatsink fins. Improve room/enclosure ventilation as needed to reduce surrounding ambient temperature.
