Cause : Power Supply Frequency Fault comes when the input power supply frequency exceeded the allowable frequency fluctuation.

1. A momentary power loss occurred.
2. Reset the fault.
3. An input power supply wiring terminal is loose.
4. Check for loose terminals.
5. The fluctuation in the voltage of the input power supply is too large.
6. Increase the Power Supply Frequency Fault Detection Width (L2-27).