| 摘要 |
Apparatus for testing continuity of a ring circuit of an electricity distribution system, for example a domestic ring main, connecting a source of electricity 302 to a plurality of accessories, being for example mains sockets. A switch 404 is opened causing a break in the ring and a detector 408 monitors the voltage at resulting ends, for example at connectors 402 and 304. A discontinuity or fault along the ring conductor results in these terminals no longer being connected and an indication, which may be the cut-off of an associated overcurrent protection device 130 or an indicator light or similar, signals lack of continuity. Preferably, the switched break is of short duration to prevent overheating of the ring circuit cable and may be operated at predetermined intervals. In some embodiments, the indicator or circuit-breaker relay latches open after a discontinuity is detected. |
