135-Kv 3,500,000-kva low-oil circuit breaker tests

A HIGH-VOLTAGE CIRCUIT BREAKER of the low-oil-content type, shown in Figure 1, was field tested in December 1951 to obtain performance characteristics on this unfamiliar design. The equipment tested was manufactured in Switzerland and is rated at 135 kv, 5 cycles, 600 amperes, and 3,000,000 kva on the European symmetrical current rating basis. Test facilities and personnel were furnished by the Bonneville Power Administration. In addition to the usual equipment there was provided a special high-accuracy cam switch designed to control accurately the relative points on the 60-cycle voltage wave at which the fault was applied and the test circuit breaker contacts parted.