Cause : Over voltage comes when the DC voltage of the main circuit increases higher than rated voltage when the motor decelerates.

"E01" fault indicate that the surge voltage generated at the power supply system.

1. Increase the deceleration time.
2. Regenerative load is at the inverter output.
3. Use Dynamic Brake Unit.
4. Line voltage is too high.
5. Check whether line voltage exceeds its rating.