TRANSIENT RECOVERY VOLTAGE CONSIDERATIONS IN THE APPLICATION OF MEDIUM-VOLTAGE CIRCUIT-BREAKERS

Medium-voltage circuit breakers can fail to interrupt three-phase faul t currents when power systems have transient recovery voltage (TRV) ch aracteristics which exceed the rating of the circuit breaker, This pap er examines the application of 13.8-kV generation and load switchgear for an oil refinery in which circuit parameters as originally designed would have exceeded the 13.8-kV circuit breakers' TRV ratings had cor rective measures not been taken, This paper illustrates this case and discusses the basis of TRV, how TRV is assessed, and alternative actio ns taken to bring circuits to within the 13.8-kV circuit breaker ratin gs.