Interruption ability of a self extinguishing type gas circuit breaker

Interruption ability of a self-extinguishing-type gas circuit breaker has been investigated while varying several structural factors. With a thermal puffer cylinder (0.7 l volume), excellent interruption ability (9.5 to 31.5 kA at 84 kV) was obtained for the condition of a breaker-terminal fault (BTF). In the condition of a short-line fault (SLF), however, its interruptible arcing time width at the same current levels was only 0.2 to 0.3 cycles, where 0.5 cycles was proposed. The critical current, which is the minimum current which the breaker can interrupt, was several kiloamperes