Functions and Selections MV: Overvoltage trip auxiliary, over-votalge protect: 270V5%.MN: Lowervoltage trip auxiliary, lower-voltage protect: 170V5%.MV+MN:When voltage overthan 270v, circuit breaker will trip to protect main power circuit;When voltage underthan 170v, circuit breaker will trip to protect main power circuit.When the line trips due to overvoltage or undervoltage, if you need to recover power, you need to pre the blue reset button to recover power.If the circuit is normally powered, pre the yellow test button to test whether the module is working properly. If the circuit breaker trips, the module is in good working condition. If the circuit breaker does not trip, the module may be damaged or the wiring is wrong. Please check or replace the module in time MX: Shunt trip auxiliary, can use voltage signal (DC24V, DC12V, AC220V, AC110V etc) to control the circuit breaker to trip quickly, which can realize the function of remote control and quick power-off.OF: Auxiliary contact, used to indicate the opening and closing status of the circuit breaker, and can also be used for fire alarm SD: Alarm auxiliary. When the circuit breaker trips due to overload, short circuit, leakage and other faults in the circuit, the auxiliary device outputs a signal. This device is mainly used for fire alarm. When the line fault is eliminated, the test lever on the device can be used to test whether there is a fault in the line. If there is no fault, the circuit breaker can be closed.OF: Auxiliary contact, used to indicate the opening and closing status of the circuit breaker, and can also be used for fire alarm OF: Auxiliary contact, used to indicate the opening and closing status of the circuit breaker, and can also be used for fire alarmAbout