F042 fault in WEG CFW900 Drive indicates a Brake IGBT Desaturation. This means the dynamic braking transistor experienced a short circuit or severe overcurrent, triggering a hardware protection trip.
Cause:
- Short circuit on the connecting cables of the dynamic braking.
Remedy:
Check connection cables of the braking resistor for insulation wear or short circuits. Verify the resistance of the dynamic braking resistor.
