Working Principle of Air Circuit Breaker

Air circuit breakers, as a normally open electrical protection device, are divided into two major components: mechanical and electrical. The core of the mechanical components is the air circuit breaker body, operating mechanism and spring energy storage system, which work together to perform the circuit breaking task. The electrical components mainly include electromagnetic coils and efficient arc extinguishing chambers, which are responsible for signal control and arc elimination in the circuit.

Operation of the air circuit breaker body: Its essence lies in the rapid disconnection of the circuit through a mechanical transmission mechanism - a pair of precise transmission rods and disconnecting contacts. After receiving the disconnection signal, a strong mechanical force is applied to the transmission rod, which drives the contacts to separate and effectively cuts off the current path.

The working principle of the air circuit breaker mainly includes two processes: movement and breaking.

Movement mechanism: When the circuit encounters abnormal conditions such as overload or short circuit, the energy pre-stored in the spring mechanism is quickly released. This energy is converted into a strong mechanical driving force, which drives the air circuit breaker body and the transmission rod to move quickly, and finally causes the contacts to separate, realizing the instant disconnection of the circuit, effectively protecting the circuit from further damage.

Breaking and arc extinguishing process: Under normal circumstances, the circuit breaker contacts remain closed and the current flows smoothly. Once an overload or short circuit is detected in the circuit, the electromagnetic coil responds immediately and generates a strong magnetic field. This magnetic field not only accelerates the separation process of the contacts, but also effectively cools and suppresses the generation of arcs through its strong magnetic force. At the same time, the built-in arc extinguishing device further intervenes and uses physical or chemical means to quickly extinguish any arc that may form. Accompanied by the "thunder sound" and dazzling flash that may be heard, this process ensures the safe disconnection of the circuit and reduces damage to the equipment.

In summary, air circuit breakers provide solid guarantees for the stable operation of power systems through their sophisticated mechanical design and efficient electrical control.