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.