Abstract :
The paper advocates a universal method of rating oil circuit breakers which will be devoid of as many variables as possible. Rating circuit breakers with reference to the aggregate full load of all synchronous apparatus alone is not sufficient to guide in the selection of the proper circuit breaker, as the location of the switching equipment and interposed lines is of equal importance. If rupturing capacity were rated as “maximum instantaneous,” meaning by “instantaneous” the elimination of time limit relays in tripping, it would eliminate all rating in reference to non-automatic, cell mounted, pipe frame, time-limit tripping, etc., and be confined entirely to the switch itself. The author suggests that all circuit breaking devices be rated with reference to the rupturing capacity on their instantaneous action.
