Field tests on high-capacity air-blast station-type circuit breakers

IN January 1940 there was presented before the Institute a paper¹ describing a new high-capacity air-blast circuit breaker. Since then, breakers of higher interrupting rating have been built, following out the general principles of design and construction disclosed at that time. As part of an organized development program, such breakers have been subjected to extensive interrupting tests under factory laboratory conditions. However, it is recognized that the final proof of the interrupting performance of high-capacity circuit breakers comes as a result of tests made on actual operating systems.