It is dangerous for unqualified, inexperienced people to meddle in any way with electrical wiring or repairs, except for matters of a very minor nature. However, mending fuses is within the competence of most householders.
The fuse box
The electricity supply cable for your home passes through your meter to a small box containing a large switch which turns the supply on and off for the whole house. This box also contains the fuses for the various wiring circuits that take the electricity around the home, and is commonly called ‘the fuse box’, although officially it is known as the ‘consumer unit’. Make sure you know the whereabouts of your consumer unit, and that the individual fuses inside are labelled.
To deal with minor electrical repairs, you should have a small electrical repair kit, kept apart from your other tools, in its own small bag or box, preferably adjacent to your fuse box. You will need a torch that works, so check the battery every now and then. A rubber-cased torch copes with knocks and bangs, but a small metal-cased torch is also useful for testing fuses, see below. You will also need an electrical screwdriver, a card of fuse wire and a selection of 13A and 3A fuses for your plugs. You could also include some candles, and a box of matches.
Mending a blown fuse
A fuse is simply a deliberately weak spot in the wiring of your home designed to blow if there is a fault in an appliance or in the wiring of the house itself, or if the circuit is overloaded because too many appliances are being used at any one time.
Fuses in your fuse-box may be of two types: they may be thin lengths of wire, called rewirable fuses. Or they may be small tubes sealed at both ends with metal caps, called cartridge fuses. In both cases, it is essential to carry out repairs with a fuse correctly rated for the circuit which it is protecting. Cartridge fuses are clearly labelled and coloured according to their rating : and fuse wire is labelled on the packaging card.
Never try to replace a cartridge fuse or fuse wire with a fuse of a higher rating, or with any kind of makeshift substitute. You should not do this even as a temporary measure. When you lose the protection of the fuse you expose yourself and your family to the dangers of tire or shock.
To replace the fuse in the mains consumer unit , you must first turn off the electricity for the whole house at the mains switch. But if you have an old wiring system, you will have several switches, all of which must be switched off until you can see which circuit is affected.
To mend a rewirable fuse: after turning off the electricity, and using the light of a 173 torch or candle if necessary, take out each fuse holder in turn, and look at the thin length of wire which it holds. The faulty fuse is the one in which the wire has broken or melted. But before you mend the fuse, try to work out why the fuse blew in the first place. If the wire seems simply to have parted, suspect overloading; I.e. using too many appliances at once. Unplug some of your appliances before mending the fuse and switching back on again. But if the fuse wire has virtually disappeared, suspect a fault in an appliance. See if you can locate the faulty appliance, and unplug it before going any further.
Loosen the screws on the fuseholder and clear away the bits of broken or melted wire. Then cut a long enough piece of fuse wire to wind around the screws at each end. The fuse wire must be of a correct rating for the circuit which it is protecting: 5 Amp for lighting circuits; 1 5 Amp for heating circuits; and 30 Amp for ring mains or large fixed appliances. Circuits for cookers may require fuse wire rated at 45 A or 60A. Wind the new wire clockwise around the screw terminals in the tuseholder at each end. Do not stretch the wire too tight.
Then you can replace the fuseholder in the box, close up the box, and turn on the main switch.
To mend a cartridge fuse: first turn off the electricity at the mains. Fit new fuse of correct rating in circuit affected. You cannot tell simply by looking which fuse has blown, as you can with rewirable fuses. You can find out either by trial and error or proceed as follows: take a small metal-cased torch, take off its end, and switch it on. Test each fuse in turn by holding it across the end of the torch, with one end resting on the battery and one on the torch casing. The sound fuses will light the torch. But first try to work out why the fuse blew.
Cartridge fuses for mains fuse boxes are rated <; Amps coloured white for lighting circuits; [5 Amps coloured blue for immersion heaters; 20 Amps coloured yellow-also for immersion heaters; and 4s Amps coloured green for cookers.
Instead of rewirable or cartridge fuses, as described above, some modern fuse boxes may be fitted with ‘miniature circuit breakers’. Instead of a fuse blowing, there is a switch which automatically turns itself off. First find out the cause of trouble as before. Then simply turn the switch back on again.
If a mains fuse continues to blow, even though you have mended it correctly, it is essential to call in a qualified electrician. Never try to replace the fuse with one of ,1 higher rating. And if all your lights and power should tail, first check with your neighbours whether there is a power cut. If there is not, call the Electricity Board’s 24-hour emergency service; it will be listed under Electricity in the telephone book.
Power cuts. Make sure that you have in your home torches and candles and/or camping lights where you can find them easily and safely even in the dark. But take particular care when using candles for they are, of course, a dangerous fire risk. Put candles well out of reach of children and when the power comes back on again, make sure that all candles are extinguished. Preferably, use heavy-based candle holders rather than a makeshift arrangement of candles in saucers; if using bottles, weight them with sand, or they could be toppled over. Non-electrical heating and a small cooking appliance are useful in extended power cuts.
As soon as you have organized some light turn off those electrical appliances which might prove dangerous if left unattended or forgotten when the power comes back on again: these include cookers and hobs, cooking appliances such.is deep tat triers, electric fry pans, irons, electric blankets, fires and so on. bridges tiittl l:reezers. Leave your fridge and freezer switched on. Check to see that the fridge drip tray is in position, then keep the fridge door closed. Do not open your freezer; its contents will remain unharmed for about eight hours. The more food you have in the freezer the longer the contents will keep without thawing. However, food which has started to thaw should not be refrozen but should be removed and eaten as soon as possible. Uncooked thawed food such as meats and vegetables can be cooked into various dishes and then refrozen.
When the power is restored, check all candles as already mentioned. Also reset electric clocks including those that control your central heating and the one on your cooker.
Above left: keep a small electrical repair kit conveniently near the fusebox. Include a rubber torch, pliers, screwdriver, fuse wires and spare fuses
Below: fitting new fuse wire in two different types </ rewirable cartridge fuse ‘74