... ) The vacuum circuit breakers use vacuum interrupters embedded in resin poles 2) Embedding the interrupter in resin makes the circuit-breaker poles particularly ... the condition of rated 12/17.5KV three phase AC voltage and 50/60Hz frequency 5) It can control and ... Rated short circuit breaking current: 25, 31.5, 40KA 4) Mechanical life: 30,000, 20,000, 10,000 times Medium Voltage Vacuum Circuit Breaker