Circuit breakers High-voltage circuit breakers and low-voltage circuit breakers are electrical protection devices. There are many types of them, and they all have arc extinguishing devices.

The full name of the air switch is an air-type low-voltage circuit breaker, which is a type of circuit breaker and is mainly used in low-voltage circuits.

Because it uses air as a medium for arc extinguishing, it is called an air-type low-voltage circuit breaker, or air switch for short. The power distribution in our usual homes is basically an air switch.

Isolation switch is a high-voltage switchgear, mainly used in high-voltage circuits. Isolation switch is a kind of switch equipment without arc extinguishing device. It is mainly used to disconnect the circuit with no load current and isolate the power supply. There is an obvious disconnection point in the open state to ensure the safe maintenance of other electrical equipment. The isolating switch can reliably pass the normal load current and short-circuit fault current in the closed state. Since the isolating switch has no special arc extinguishing device, it cannot cut off the load current and short-circuit current. Therefore, the isolating switch can only be operated when the circuit has been disconnected by the circuit breaker. It is strictly forbidden to operate with load to avoid serious equipment and personal accidents. Only voltage transformers, lightning arresters, no-load transformers whose excitation current does not exceed 2A, and no-load circuits whose current does not exceed 5A can be directly operated with isolation switches.

In electric power applications, circuit breakers and isolating switches are mostly used in combination. Circuit breakers are used to control load current, and isolating switches are used to form an obvious disconnection point.