Analysis on the damage reason of vacuum circuit breakers

The vacuum circuit breaker with more advantages after such long years of application experience in power system, more than 20years used in China, from the early 1980´s till now has committed kinds of damage. In this paper the damage reasons for the vacuum circuit breaker rated 10kV, 35kV is summarized which are typically mechanical malfunction, relay protection, the leakage of vacuum and so on. Among these reasons one is emphasized and analyzed thoroughly and the method to avoid the damage is presented and discussed