Study On The Reliability Of Miniature Circuit Breakers

Miniature circuit breakers, one kind of protective electrical apparatus, are mainly used in household and industrial installations and distribution system for overload and short circuit protection. Their reliability level directly influences the power supply in house and industrial installations the safety of facilities in distribution system, so the failure of miniature circuit breakers will result in/cause extremely serious loss. In addition, the characteristic and failure modes of miniature circuit breakers are not only different from typical controlling apparatus, but also from other protective type electrical apparatus such as measuring relays. Thus, it is not suitable to introduce their reliability indexes and reliability test plans directly into those of miniature circuit breakers. Therefore, it is significant to study the reliability of miniature circuit breakers. For miniature circuit breakers, this paper analyzes its reliability indexes and reliability test methods, adopts failure rate and success rate as its reliability characteristic parameters. Furthermore, this paper studies the general requirements for the reliability test, describes the preparation of test pieces, test conditions, the test items to be examined, test methods and the criterion of failure, and the reliability compliance test plan. and test program. The reliability test device of miniature circuit breakers has been developed with applied software. To carry on the reliability test of typical miniature circuit breakers, analyze their failure mechanism and to put forward some measures to prove the reliability level of miniature circuit breakers. II To study the reliability screening test methods of miniature circuit breakers.