The molded case circuit breaker (MCCB) has three-stage protection function. The circuit breaker of class B has full selective cooperation with other short-circuit devices connected in the same circuit under short-circuit conditions. It has five kinds of disconnection characteristics: the user can adjust the LED lighting setting of the release according to the load current requirements; the electronic release is provided by the circuit breaker itself, current signal and control power supply From the ring current transformer installed in the circuit breaker.

With warning indication: when the load current exceeds the predetermined current, the light-emitting secondary attention on the cover of the circuit breaker is yellow; with overload indication: when the load current exceeds the setting current, the light-emitting secondary attention on the cover of the circuit breaker is red; with overload non disconnection for fire protection only alarm function: when the load current is overloaded, the circuit breaker does not disconnect, output 1 Each passive contact signal drives the corresponding alarm device; the overall dimension is the same as that of HZMB Series Molded Case circuit breaker, and the installation is interchangeable.

Molded case circuit breaker has the advantages of adjustable action value, high breaking capacity, convenient operation and safety, so it is widely used at present. Structure and working principle the low-voltage circuit breaker is composed of operating mechanism, contact, protection device (various releases), arc extinguishing system, etc.

The function of molded case circuit breaker is to cut off and connect the load circuit and cut off the fault circuit, so as to prevent the accident from expanding and ensure the safe operation. However, the high-voltage circuit breaker needs to disconnect 1500V and 1500A to 2000a arc, which can be stretched to 2M and still burn continuously. Therefore, arc extinguishing is a problem that must be solved for high voltage circuit breakers.