Worldwide reliability survey of high-voltage circuit breakers

CIGRE 13.06 Working Group has conducted two worldwide reliability surveys of the reliability of high-voltage circuit breakers of 63 kV and above. The first enquiry included 78000 breaker-years of "in-service data" from 102 companies in 22 countries during the years 1974 through 1977 and included all interrupting technologies. The second enquiry included 70708 breaker-years from 132 companies in 22 countries for the years 1988 through 1991 and included only single-pressure SF/sub 6/ breakers because this is what most companies are now buying. Thirty-one US utilities and industrials submitted data. The results are briefly outlined.