Electric Wiring, 3rd Edition

46 Wiring lighting points

Fig.

4.10. A cord-operated 5 A ceiling switch

Lighting fittings

Where conduit systems are employed, it is usual to use a standard circular

iron or steel box to BS

31,

with some form of back outlet so that the lower rim

of the box does not come below the surface of the plaster. This gives a

convenient outlet to which a ceiling rose or ceiling plate may be fixed. The

standard box has two fixing lugs drilled and tapped at 51 mm centres for

fixing a direct-mounting surface or semi-recessed ceiling rose, a batten

lampholder or, where connectors are used in the box, a pendant or hook

plate. Wall bracket lights may be similarl ...