Oil circuit breaker investigation as carried on with a 26,700-kv-a. generator

ALTHOUGH oil circuit breakers have been used for a number of years and many successful designs produced, the work of the designer has been handicapped by the lack of definite design constants, based on experimental results. On some of the earlier designs, field tests were relied upon for the confirmation of the interrupting rating. Such tests were of great value, but, due to the inherent erratic behavior of oil circuit breakers as a current interrupting device, the data obtained was not usually of a general or fundamental nature. To remedy this situation and to permit continuous and consistent research on the interrupting characteristics of alternating-current circuit-controlling devices, a special testing equipment was installed. 1