High-voltage oil circuit breakers for transmission networks

THE standards of the American Institute of Electrical Engineers define an oil circuit breaker as a “device (other than a fuse) constructed primarily for the interruption, in oil, of a circuit under infrequent abnormal conditions.” Common usage, however, has sanctioned the use of the term “circuit breaker” as applying to a device for the regular and usual interruption of an energized circuit as distinguished from a switch used only for opening circuits which are de-energized or not carrying load. This paper will consider only high-voltage oil circuit breakers, the term “high voltage” being taken as applying to potentials of 25,000 volts or above.