MHZM3L plastic case circuit breaker is suitable for AC 50Hz, rated voltage of 400V and below, and rated current of 10A to 800A in power distribution networks. It is used to provide indirect contact protection to humans or other animals, and it can also be used to prevent equipment insulation from aging and damage. Caused by leakage and other safety accident protection, leakage circuit breaker can be used to distribute electrical energy and overload and short circuit protection. Under normal circumstances, the circuit breaker can be used for the infrequent switching of the line and the infrequent starting of the motor respectively.