An SF6 circuit breaker using the autoexpansion principle

An SF₆ circuit-breaker which uses the principle of autoexpansion, a combination of rotary arc and self-pressurization principles, is discussed. The operating principles and the design considerations involved in this interruption technique are examined. The principal performance features are given, particularly in comparison with existing SF₆ techniques. Details of the research techniques and diagnostic systems that have facilitated the design and development of this circuit-breaker are given