HV Circuit Breaker

High Voltage  circuit  breaker (including  breakers  rated  at  intermediate  voltage) is used  for service on circuits with voltage ratings higher than 600 volts.  Standard voltage ratings for these circuit breakers are from 4,160 to 765,000 volts and three-phase interrupting ratings of 50,000 to 50,000,000 kVA.

In  the  early  stage  of  electrical  system ,  the  major  portion  of  high-voltage  circuit breakers  were  oil  circuit  breakers.   Later,  magnetic  and  compressed-air  type  air  circuit breakers have been developed and are in use today.