Field Tests and Performance of High-Speed 138-Kv Air-Blast Circuit Breaker

Since 1926 many significant field tests on high-voltage circuit breakers have been made on the American Gas and Electric Company´s central system, which have served as an important aid in highvoltage circuit breaker development. Such tests have also served as a means for studying and checking the behavior of this large power system under short-circuit conditions. A 138-kv air-blast breaker of novel design has recently been given a series of field for ultrahigh-speed reclosing service. Cirthat expected of any modern oil breaker of conventional design was obtained and, in addition, an unusual superspeed reclosing performance was obtained which points the way to a possible liberalization of existing derating factors for this kind of service. While still somewhat of an innovation in the high-voltage field, the air-blast circuit breaker undoubtedly has certain basic advantages. It is believed that these tests are an important step forward in developing the possibilities of the air-blast breaker for high-voltage service and that they have brought the entire electric power industry closer to the possibility of benefit from an application of this interrupting principle.