The Causes of Failure to Operate a 500 kV Circuit Breaker
In this work,we investigated the causes of a circuit breaker failing to operate in early of 2022 at a power supply bureau of Yunnan Province.The results show that severe corrosion of ejector pin is the main reason for failing to operate the circuit breaker.Surface zinc coating of ejector pin is easily react with O2 in local humid environment.Basal body of ejector pin with a carbon steel material is then severely oxidized after zinc coating is broke.To avoid this situation,chromate treatment is recommend in humid environment for carbon steel ejector pin for anti-corrosion or just choose stainless steel ejector pin.