Analysis on failure modes of miniature circuit breaker

In recent years, intelligent miniature circuit breaker has emerged and is developing quickly. As a new thing, it still has high failure rate. In this paper, about 64418 failure cases of traditional case circuit breaker and 25063 failure cases of intelligent circuit breaker were collected to analyze their failure modes, which is benefit to improve the quality of the intelligent circuit breaker. It is found that the most important failure mechanism is the burned caused by high contact resistance or over load. And the high contact resistance is caused by several reasons such as the wire has not been tightened enough, the copper wire is replaced by multi-strand aluminum wires, and the quality of the wire terminal on the breaker is not thick enough. Finally, several measurements are put forward to improve the reliability of the breaker.