FCX-12HP分相操作箱防跳继电器烧毁事故原因分析

his paper analyze the cause that an anti-pump relay and signal relay in the protection equipment are burned due to the SF6 circle breaker‘s auxiliary contact not switching. As we can see if the circle breaker‘s auxiliary contact not switching, not only the circle breaker will be failure to operate, but also the component in the secondary circle will be burned. Moreover, it is not easy to find out the burned components if the anti-pump relay burned firstly and the signal relay , circle breaker can still work, because in this situation, the phenomenon of the burning accident is not evident, especially if the relay is burned after commission testing. When the burned components not be find out in time, it result in the equipment operating with the defects. Therefore, if the circle breaker‘s auxiliary contact not switching during the commission testing or operating, the related secondary circle must be checked in detail but not only checking the circle breaker itself.