Molded case circuit breaker( MCCB ) has the following common functions:

1. Auxiliary contact (auxiliary switch). They are electrically isolated from the main contact and are suitable for alarm and program switches. In addition to being used for alarm, the standby power can also be switched on in important applications.

2. Driver. With the switch on / off switch transmission speed is 2 times of the molded case circuit breaker, can save cost and board space; push-pull driver in the event of emergencies is most stable.

3. Shunt terminal. Unlike conventional circuit breaker contacts, current sensing elements, and loads, the shunt terminals separate the main circuit from the main circuit, allowing secondary loads to be switched in. If the primary load is short circuited or overloaded, the circuit breaker will trip and cut off the power supply of the 2 loads. Different from the auxiliary contact terminal is received, shunt circuit breaker located between the switch contacts and current sensing elements, which means that the second load will not overload or short-circuit protection, to protect the secondary circuit requires the use of a separate circuit breaker, otherwise the circuit can be used only with built-in protection circuit device.

4. Duplex control (remote tripping or relay tripping). A multiple control molded case circuit breaker combines 2 electrically isolated inductive elements to perform a plurality of functions. For example, can be used to control the actuator or sensor, over-current protection circuit and disconnect the traditional.

5. Low voltage trip. This is a separate voltage sensitive element in the circuit breaker. If the voltage drops below a predetermined value, it will open the main contact. Switching circuit breakers with low voltage tripping are widely used for on-off / on-off control of wire connected electrical apparatus.

6. Automatic trip. In the design of a fully automatic tripping, when the driver is kept in the "on" position, the circuit breaker will periodically switched on and off.

7. Automatic reset. For narrow space, suitable for automatic reset after the cooling period of the circuit breaker.

In a word, the selection of circuit breaker should be concretely analyzed according to the specific situation so that it can really play a role.