What is a circuit breaker?

A circuit breaker is an automatically operated safety switch that operates by measuring the heat or current flowing through the circuit. If the preset limit is exceeded, they will 'trip' and cut off the power as soon as possible. Unlike fuses, once the fault is corrected, there is no need to replace it, just reset it.

Need a circuit breaker

Circuit breakers are an essential part of any electrical system. When used in conjunction with appropriate grounding, they can prevent electric shock. Circuit breakers can also protect electrical appliances, wires, and property from fire and other damages caused by abnormal currents, short circuits, overloads, and heat accumulation.

Almost all circuit breakers have five basic components:

1. Shell: This is the shell that wraps around other parts. According to the rated current and voltage, they can be further divided into three types:

Plastic case: usually used for low-voltage circuit breakers

Insulated enclosure: used for circuit breakers rated for medium voltage and amperage

Metal cladding: typically used for high-end medium-sized circuit breakers

2. Electrical contacts: There are two contacts in the circuit breaker - fixed contacts and floating contacts (controlled by the circuit breaker). When the circuit breaker trips, the floating contacts will move away from the fixed contacts and disconnect the power supply of the circuit.

3. Arc extinguishing mechanism: When the contacts are disconnected, electricity will jump through the gap between the last contacts. This will generate an arc, which can reach very high temperatures. In order to prevent damage and prevent the arc from regenerating on its own, the circuit breaker uses an arc extinguishing mechanism to prevent these arcs.

4. Main operating mechanism: The circuit breaker can use multiple methods to disconnect the power supply. These can include spring switches, solenoids, hydraulic and pneumatic switches.

5. Trip element: The current flowing through the circuit will generate heat and magnetic field. The tripping element has been calibrated to measure current and voltage using one or both of these factors, and to trip the switch when exceeding the maximum rated value.