Domestic Electrical Circuits

Ring Circuits: The most common form of power circuit for feeding the socket outlets is the ring circuit. With this method of wiring a cable starts from the main electrical unit and goes around the house connecting socket to socket and arriving back at the main unit. This means that power can reach any socket from both directions reducing the load on the cable.

Ring circuits are always run with 2.5mm cable and are protected by 30amp fuses. Theoretically there is no limit to the number of socket outlets that can be fitted. In practice two storey houses usually have one ring circuit for the downstairs and one for the upstairs.

Radial Circuits: A radial power circuit feeds a number of sockets but its cable terminates at the last socket. Any number of sockets can be supplied by one of these circuits. A powerful appliance like a cooker or shower unit must have its own radial circuit.

Lighting Circuits: Domestic lighting circuits are of the radial kind but there are two systems currently in use. The loop system simply has a single cable that runs from ceiling rose to ceiling rose and terminates at the last one in the circuit. The junction box system incorporates a junction box for each light. A cable runs from each junction box to the ceiling rose and another from the box to the light switch.