Cause : Control Power Fault comes when the control power supply voltage dropped due to the wiring of the control power circuit is incorrect or Backup Capacitor Unit for Momentary Power Loss is not attached to a 200 V/400 V Class Inverter of 7.5 kW or less and the value of the Momentary power loss ridethru time (L2-02) factory setting has been changed to the larger value.

1. Try turning the power supply off and on. 
2. Replace the Inverter if the fault continues to occur. 
3. Attach a Backup Capacitor Unit for Momentary Power Loss.