Cause : MC Answer- back(Inrush Prevention Circuit Fault) comes when a fault occurred in the surge prevention circuit. The magnetic contactor did not respond for 10 s even though the magnetic contactor ON signal has been output.

1. The magnetic contactor in the main circuit failed. 
2. The magnetic contactor excitation coil is burned out.
3. Try turning the power supply off and on. 
4. Replace the Inverter if the fault continues to occur.