A wall light is fixed by its baseplate either to a box sunk into the wall or it is fixed direct to the wall. The box, termed ‘BESA’ box, is a termination box to contain the ends of the circuit wires from which the sheath is removed, and a flex connector which joints the wires to the flex of the fitting.
Only wall lights having a baseplate with 50 mm (2 in) fixing centres to match the lugs in the box can be mounted on this circular box. Most wall lights have other types of baseplate of which there are many shapes and sizes. Read the rest of this entry »
Plain and twisted candle lamps are made in 25 W, 40 W and 60 W sizes and in pearl, plain, amber and silvered colours. They are made in be (bayonet cap) and sbc (small bayonet cap) versions.
These are used for wall lights and for period pendant fittings.
These are sometimes called ’strip lights‘ and are non-fluorescent, being tungsten filament lamps. There are two versions, one type is commonly used for applications in the home, and the second type is known as architectural lamps‘. 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 »
Of the two principal types of cooker control unit, the type incorporating a kettle socket-outlet is the more popular. Since, however, it is important that the kettle is not used on the cooker hob where its flex would trail over a switched-on boiling plate it is better to have the unit without a socket where it has to be fixed immediately above the cooker. 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 »
A fused clock connector is a small non- switched fused outlet designed expressly for supplying a mains electric clock.
The unit is in two sections: a fixed base which is connected to the fixed circuit wiring, and another section in.the form of a flat pin plug which plugs into sockets in the base. The plug section carries the flex of the clock and contains the fuse. The plug is secured in the base by a retaining screw. This prevents the plug being pulled out accidentally and stopping the clock. Read the rest of this entry »
Portable electric heaters and many fixed electric heaters are controlled by a switch or switches mounted on the frame of the heater. In addition, the heater is switched at a switched socket-outlet or switched fused connection unit or is connected to a non-switched socket-outlet which means pulling out the plug to switch off the heater.
Wall panel heaters, oil filled radiators, convectors and other heaters operating at ‘black heat’ have an integral thermostat which is set to the required room temperature. Read the rest of this entry »
Most people have a healthy respect for electricity and understand that it can be dangerous — even lethal — if misused. Electricity at all voltages should be respected. Anyone who does not follow the basic rules of electricity is not only a danger to himself but to everyone around him. Electrical accidents are avoidable: most are due to plain carelessness and failing to follow the basic rules.
There are about sixteen million homes in Britain supplied with electricity and each one contains an average of about 25 electrical appliances. Given the sheer number of items, it is perhaps surprising that there are fewer than 80 fatalities from electrical accidents a year. Although this represents only a small percentage of the entire population and represents only one per cent of the 8,000 deaths each year that result from accidents in the home, the figure is still far too high. Read the rest of this entry »
Formerly imperial ratings were used for fuses and circuit breakers, but the international Renard ratings have now been added and will supersede them.
Fuse manufacturers are still using the imperial sizes while circuit breaker manufacturers have mostly changed to the new ratings. An equivalence chart is shown above.
The miniature circuit breaker (MCB) is now widely used and overcomes all the problems associated with ordinary fuses. It is a small, sophisticated unit affording a much higher level of protection than an ordinary fuse. It is tamper-proof and the unit involved is easily identified when one has tripped (the switch moves to the ‘off’ position). Most importantly, MCBs cannot be reset if the fault still exists; this eliminates the foolish and highly dangerous practice of putting in the wrong fuse wire or cartridge just to get things ‘conveniently’ working again for the time being. Read the rest of this entry »
