Circuit breaker is a switching device that can close, carry and open the current under normal circuit conditions and can close, carry and open the current under abnormal circuit conditions within a specified period of time. Circuit breakers are divided into high-voltage circuit breakers and low-voltage circuit breakers according to their scope of use. The division of high-voltage and low-voltage boundaries is rather vague, and those above 3kV are generally referred to as high-voltage appliances.
Circuit breakers can be used to distribute electrical energy, start asynchronous motors infrequently, protect power lines and motors, etc., and automatically cut off the circuit when they are seriously overloaded or short-circuited and under-voltage faults, and their functions are equivalent to the combination of fuse-type switches and over-under thermal relays. And after breaking the fault current generally do not need to change the parts. Has been widely used.
Electricity generation, transmission and use, power distribution is an extremely important link. Distribution system includes transformers and a variety of high-voltage electrical equipment, low-voltage circuit breakers are a kind of electrical appliances used in a large number of areas.