Vacuum Circuit Breakers are the circuit breaker that contacts and breaks contacts in vacuum.

The Vacuum Circuit Breakers were first studied by Britain and the United States, and then developed to other countries such as Japan, Germany and the former Soviet Union. China began to study the theory of vacuum circuit breakers in 1959 and formally produced all kinds of vacuum circuit breakers by the beginning of 1970s. The continuous innovation and improvement of vacuum interrupters, operating mechanism and insulation level make the development of vacuum circuit breakers rapidly, and a series of important achievements have been achieved in the research of large capacity, miniaturization, intellectualization and reliability.

The Vacuum Circuit Breakers have good arc extinguishing characteristics, suitable for frequent operation, long electric life, high reliability and long period of non maintenance. It has been widely used in the power industry in our country, such as urban and rural power grid transformation, chemical industry, metallurgy, railway electrification and mine industry. From several ZN1-ZN5 varieties in the past to dozens of models and varieties, the rated current reached 4000A, the breaking current reached 5OKA, even 63kA, and the voltage reached 35kV grade.