Dethermalizing Arc Quenchers

The primary function of the normal-type oil circuit breaker is to interrupt the circuit as rapidly as possible, without disturbing the connected system, and to leave the oil circuit breaker in substantially the same electrical and mechanical condition as before. The interruption of an electrical circuit is always accompanied by an arc, and it has been found that if the arc and its associated space are rapidly cooled or dethermalized it is readily extinguished. This paper describes dethermalizing arc quenchers that cause the arc and its associated space to be cooled by the controlled flow of oil through and around the arc. The action of these quenchers has been verified by field tests on the 16-kv and 220-kv systems of The Southern California Edison Company Ltd.