``De-ion'' Air Circuit Breakers for A-C Feeder, Motor Starting, and Station Auxiliary Service

The first circuit interrupters for a-c service were of the air-break type, followed very shortly by oil circuit breakers for general high-voltage service. Air ``Deion'' circuit breakers introduced in 1928 provided a new type of circuit interrupter for a-c service. Recent applications of these principles result in a line of De-ion air circuit breakers for 2,500-volt and 5,000- volt ratings suitable for use in a-c feeder circuits, motor starting, and general station auxiliary service.