F0051 fault in WEG CFW701 Drive indicates an IGBT Overtemperature. This means the internal power transistors have exceeded their safe thermal limits and the drive has tripped to prevent hardware damage.
Cause:
- High surrounding air temperature (>50 °C (122 °F)) and high output current.
- Blocked or defective cooling fan.
- Very dirty heatsink.
Remedy:
Clean the heatsink fins. Inspect the cooling fan and replace if defective. Check ambient room temperature.
