Circuit Breakers for Boulder Dam Line

The trend in recent years toward large concentrations of electric power at important centers and the necessity for stable transmission over ever-increasing distances have resulted in a demand for high voltage switching equipment with unusually short operating time. This paper describes the development along conventional lines of a circuit breaker of the deionizing grid type capable of interrupting within 3 cycles a short circuit on a 287.5-kv 60-cycle line.