F30021 fault in Siemens V70 Drive indicates a Ground fault. This means electrical current is escaping to the earth ground, usually caused by damaged insulation on the motor cables or inside the motor windings.
Cause:
Power unit has detected a ground fault.
- Ground fault in the power cables.
- Winding fault or ground fault at the motor.
Remedy:
- Check the power cable connections.
- Check the motor.
