Domestic electric lighting circuits

Lighting cable:
Unlike the ring power circuit, the lighting circuit does not form a loop returning to the consumer unit. The consumer unit is normally connected to the first lamp, which in turn is connected to the second lamp and so on.

The cable used is a 1sq mm PVC twin core and earth rated for up to 12 amps. It consists of a red insulated core for live, black insulated core for neutral with a bare earth conductor between them. The three conductors are laid side by side within a PVC sheath. When connecting the cable, the exposed earth connector must be covered with a sleeve coloured yellow and green (to denote that it's an earth).

The lighting cable is routed from the consumer unit to a series of lighting points for ceiling roses or wall light fittings. The power to each lamp is connected via a wall or ceiling mounted switch. Some light units incorporate their own switch, for these fittings, the power circuit is then connected directly to the fitting.