Circuit breaker refers to a switching device that can turn off, carry and turn off the current under normal loop conditions and can turn off, carry and turn off the current under abnormal loop conditions within a specified time.

The circuit breaker is generally composed of a contact system, an arc extinguishing system, an operating mechanism, a release device, and a housing.

The function of the circuit breaker is to cut off and connect the load circuit, as well as cut off the fault circuit, prevent the expansion of the accident and ensure safe operation. The high-voltage circuit breaker to break 1500V, the current is 1500-2000A arc, these arcs can be stretched to 2m still continue to burn not extinguished. So arc extinguishing is a problem that high voltage circuit breaker must solve.