Ring and Radial Socket Outlet Circuits

Remember, however, that it is impossible to catalogue every fault and its cause that may occur in every system.

Diagnostic flow charts have been included for some of the following faults.

RING AND RADIAL SOCKET OUTLET CIRCUITS Reported fault

‘My fuse/circuit breaker blows at odd unspecified times during the day, with no particular appliance plugged into any particular socket. ’

Diagnosis

1. This could be incorrect fusing, but that is unlikely because then the fault would always have been present. It is probably an insulation breakdown. 2. Conduct an insulation resistance test (remember to remove all appliances). If the reading is low, then: 3. Go to the centre of the circuit and disconnect the socket; disconnect the ends in the fuse board if the circuit is a ring; and test in both directions. 4. Probably only one side will indicate a fault, so subdivide.

Keep testing and subdividing until the faulty cable section or socket is located ( Figure 4.3 ).

New ring final circuit installations

In Chapter 3 three methods are described for testing the continuity of the final conductors. The purpose is to locate interconnections in the ring. Should such an interconnection prove to exist, its position in the ring must be located. Methods 1 and 2 will indicate a fault, but location is achieved by systematically removing sockets