MHZV2 self-resetting over-voltage protector is suitable for AC 50Hz, rated voltage 230V, 400V, rated current 32A to 100A, to cut off the power supply quickly and reliably when there is overvoltage or undervoltage in the line to ensure the safety of the load. When the voltage returns to the normal value, the circuit can be automatically turned on after a delay to restore the power supply, effectively protecting the load from shock hazards when the power is turned on.