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 »
Some fluorescent fittings have no starter switch(s) for the tubes. Instead there is S transformer to provide the prewarming and the tube itself has a metal stripe running throughout its length from one lamp cap to the other. The lamp caps are earthed at the lampholders.
This assists in the starting of the electron flow and, as there is no starter to operate, the lamp strikes without the characteristic delay of the switch-start type.
A fluorescent tube has an expected life of 5000 to 7000 light hours or up to seven times that of an electric light bulb. 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 »
Storage heaters require a separate circuit for each heater. This is because, unlike direct acting heaters which are switched on and off as required, storage heaters are all switched on together during the 8-hour period. They cannot therefore be supplied from a ring circuit which is based on diversity of use of various appliances; each heater must have its own circuit. Read the rest of this entry »
