High voltage vacuum circuit breakers

A new line of high voltage vacuum power circuit breakers is being developed for 121 kV and above and will use the new vacuum interrupter module presented in a companion paper³. The first ratings in production will be 242 kV with interrupting capabilities of 40,000 amperes, followed by breakers rated 50,000 amperes; both of these will have continuous current ratings of 2000 and 3000 amperes. This paper departs from normal practice by submitting the new vacuum circuit breaker design concepts prior to manufacture. A future paper on the breaker testing program and test results will be submitted to the Institute. The breakers will be dead tank design and use SF6gas only for insulation purposes. The interrupter contacts are to be mechanically driven by charged-spring type operating mechanisms. The breakers will be supplied for conventional outdoor switchyards and for high voltage gas-insulated station equipments.