| 摘要 |
A fault protection apparatus 10 for an electrical distribution system, in particular a ring main unit comprises a plurality of feeders 12. A respective switching device 16 is provided in each feeder between a common feeder connection point and a respective feeder terminal and a respective feeder protection device associated with each feeder. Each feeder protection device comprises a sensor 22 and a feeder protection relay 24. The feeder protection relay is coupled to the respective switching device and is operable by the sensor to operate the respective switching device. A first terminal of each feeder protection relay is connected to the a terminal of the respective sensor, a respective second terminal of at least two feeder protection relays is connected to a common relay connection point, and a respective second terminal of the respective sensors of the at least two feeder protection relays is connected to a common sensor connection point. The apparatus further comprises an internal protection relay connected to the common relay protection point and the common sensor protection point. |
