The home lighting system consists mainly of lighting circuits devoted to supplying fixed lighting only. Other lighting is sometimes termed auxiliary lighting, but in some rooms this may, in fact, constitute the main lighting.
Auxiliary lighting comprises spot lights, pelmet lighting and other special lighting and effects. Read the rest of this entry »
Socket-outlets situated off the main route of the cable do not have to be connected to the actual ring cable. Instead they are usually supplied from spur cables branching off the ring. These spurs are wired in the same size cable as that used for the ring.
Fixed appliances which may be connected to a ring circuit include skirting heaters, wall heaters, small water heaters and any non-portable electrical appliances having individual loadings of not more than 3000 W(13 A approx.). Read the rest of this entry »
A radial power circuit is the name given to a circuit supplying a number of 13 A socket-outlets and fixed appliances using one cable which is not wired in the form of a ring but terminates at the last outlet.
The permitted number of socket-outlets (and fixed appliances) depends on the current rating of the circuit which can be either 20 A, wired in 2.5 mm2 cable, or 30 A wired in 4 mm2 cable. The number of socket-outlets and fixed appliances which can be served by a 20 A radial circuit depends also on the location of the circuit and whether the outlets are confined to one room. Read the rest of this entry »
Electric heating of water can be carried out in a variety of ways. These include small capacity heaters fitted above the sink, instantaneous sink heaters or immersion heaters in the hot water tank.
Small storage water heaters fitted over the sink or washbasin having capacities of up to about 3 gallons and electrical loadings of 1 to 3 kW are usually supplied from the ring circuit by means of a spur. Except in a bathroom, the outlet can be a fused plug and switched socket-outlet, preferably with neon indicator. Read the rest of this entry »
Joint boxes are usually circular and for part of the circuit wiring. They are fix permanently to the house structure are used principally in lighting circuits. Join boxes are available in 4- 5- and 6-terminal versions.
A 3-terminal joint box of 30 A current rating is used for ring circuits to connect spur cables to the ring cable, as shown the illustration. Read the rest of this entry »
