High-voltage circuit breakers

The 150-kv. system operated for some years by the Southern California Edison Company has not made use of automatic operation of circuit breakers. The multiplication of generating stations and connections which accompanied the change to 220-kv. makes desirable the automatic section-alizing of the line in cases of trouble and, therefore, requires circuit breakers for automatic operation similar to that obtained on more moderate voltage systems. Circuit breakers have been manufactured for this service with high rupturing capacity and the designs have followed closely the standard designs for more moderate voltages.