That is, when the line failure, the relay circuit breaker tripping, the device auto-reclosing after a short time interval, so that a re-breaker.
即当线路出现故障，继电保护使断路器跳闸后，自动重合闸装置经短时间间隔后使断路器重新合上。
2
A pig indicator or "pig sig" is used to detect the passage of the pig and alert the operator by tripping a suitable warning device.
清管器指示器或“清管器发讯器”用来探测清管器是否通过、并启动报警装置通知操作人员。
3
Relay box is an operational device to tripping and closing of breaker instructed by protection, breaker controlling unit, monitor unit, and auxiliary device of breaker.