1. After the vacuum circuit breaker trolley in the high-voltage switchgear is closed in the test position, the trolley circuit breaker cannot enter the working position. (Prevents closing with load)
2. When the grounding knife in the high-voltage switchgear is closed, the trolley breaker cannot be closed. (Prevent closing with ground wire)
3. When the vacuum circuit breaker in the high-voltage switchgear is closed, the back door of the panel is locked with the machine on the grounding knife and the door. (Prevent the charging interval from being mistakenly entered).
4. The vacuum circuit breaker in the high-voltage switchgear is closed during operation, and the grounding knife cannot be turned on. (To prevent the ground wire from being charged)
5. When the vacuum circuit breaker in the high-voltage switchgear is closed for operation, it cannot exit the working position of the trolley circuit breaker. (Prevent pull broach with load)