Wire and cable MCB

Miniature circuit breaker, referred to as MCB (Micro Circuit Breaker/Miniature Circuit Breaker), is one of the most widely used terminal protection devices in building electrical terminal distribution devices. It is used for single-phase and three-phase short circuit, overload, overvoltage and other protection below 125A, including four types: single-pole 1P, two-pole 2P, three-pole 3P and four-pole 4P.

Working principle of MCB

The miniature circuit breaker is composed of operating mechanism, contact, protection device (various releases), arc extinguishing system, etc. Its main contact is closed manually or electrically. After the main contact is closed, the free release mechanism locks the main contact in the closing position. The coil of the overcurrent release and the thermal element of the thermal release are in series with the main circuit, and the coil of the undervoltage release is in parallel with the power supply. In case of short circuit or serious overload of the circuit, the armature of the overcurrent release will be closed to make the free release mechanism act, and the main contact will disconnect the main circuit. When the circuit is overloaded, the heating of the thermal element of the thermal release will bend the bimetallic sheet and push the free release mechanism to move. When the circuit is under voltage, the armature of the undervoltage release is released. It also makes the free release mechanism act

Differences between mccb and mcb circuit breakers

1. Different types. MCCB is molded case circuit breaker, while MCB is miniature circuit breaker; 2. The installation position is different. MCCB is mostly installed in the middle of the line, while MCB is mostly used at the load end; 3. The breaking capacity is different. The breaking capacity of mccb is better than that of mcb; 4. Different sizes. The volume of mccb is larger than that of mcb