Late Model 230-kV Oil Circuit Breaker

Recent reports on the performance of oil breakers give the impression that they are not suitable for use on modem transmission systems. They imply that oil circuit breakers have reached a design maturity and that they cannot be made adequate for today's use. The record should truthfully say that these comments are applicable only to older oil circuit breakers and not to those of modem design. A 230-kV oil circuit breaker that was developed within the past year and designed to meet today's requirements is discussed. This involves meeting the requirements of ASA Standards C37.03 to C37.010 (Symmetrical Basis of Rating). It has a 20 000-MVA interrupting rating and a 2000-ampere continuous current rating. A description of the breaker and a full complement of test results are included.