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 »
If only one appliance suddenly stops working and there were no flames, sparks or big bangs to indicate that it was a malfunction in the appliance itself, unplug it and try it in a different socket. If it is still not working, check the cord’s connection with the plug, as well as the appliance, If one of the connections seems loose or frail, unplug the appliance and try to repair the connection. You will either have to unscrew the plug, or dissemble the appliance to get to the cord connection. Read the rest of this entry »
These have a similar motor to the vacuum cleaner; the most common fault being brush wear. Burning out of the windings is also fairly frequent and is usually caused by overloading due to misuse.
The popular low-priced rotary mowers are usually powered by a brush motor similar to that of an electric drill (power tool). Carbon brushes need replacing when they wear but the component which is likely to give the greatest concern is the thermal cutout usually situated in the handle. The function of this is to cut off the current to the motor when there is a risk of overload when cutting very long grass. Read the rest of this entry »
Take particular care in the bathroom where special regulations apply.
Do not install a socket-outlet in the bathroom other than an approved shaver supply unit for a mains voltage shaver.
Do not make provision for using a mains voltage portable appliance. For example do not run a portable electric heater from a socket-outlet situated outside the bathroom i.e. on the landing or in an adjacent bedroom. If the tank cupboard opens into the bathroom and the tank has an immersion heater do not supply it from a socket-outlet (not a good method in any case) which could be used for plugging in a portable appliance. Read the rest of this entry »
Most, if not all, people know that mains electricity in the home is lethal. This means that if you come into contact with a live terminal, live wire or metalwork, which because of a fault is charged with electricity, you will receive an electric shock which could be fatal.
Electricity at the mains voltage of 240 V is present at every ceiling rose, lampholder, switch, socket outlet and other outlets. It is also present at every electrical appliance connected to the mains when plugged into a socket outlet and the switched socket is ‘ON’. 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 »
The earth path of an appliance can be checked easily using a simple test meter. Remember, path of low resistance is required from all items within a appliance that are linked into the earth path via the yellow and green cable.
The earth path of an appliance from its exposed metal parts to the earth pin of the plug should be a maximum of 1 ohm (BS3456).
Checking the earth path of a socket requires an earth loop test meter which needs to be operated correctly. This is an expensive item and, moreover, problems may be encountered with distribution boards fitted with an RCD. It is, therefore, advisable to have these tests done by a qualified electrical contractor. Read the rest of this entry »
Problems with electrical appliances may not always result from a failure of the equipment itself. They can be caused by the failure of electrical supply to the appliance via the socket. A three-pin socket must have a live supply, a neutral return and a sound earth path. When a plug from an appliance is inserted, firm contact must be made at all three points. If the live or neutral pins of the plug or connection point within the socket fail to make adequate contact or are free to move, localized heating will occur within the socket. Typical signs of this problem are listed below.
There are various reasons for such problems. They may be caused by one or a combination of any of those listed here. Read the rest of this entry »
All the mains appliances featured here have some kind of mains cable. Problems with the electronic cables of portable appliances are quite common, especially those that are moved around constantly while in use, such as vacuum cleaners and hedge cutters.
The problems can range from a simple break in one or more of the conductors, which would render the appliance open circuit, to the breakdown of the cable’s insulating properties caused by damage, fatigue or neglect, leading to the risk of electric shock or fire. Electronic cables and extension leads must be checked regularly and thoroughly.
There are several different types of flexible electronic cable in two-core and three-core configurations on the appliances shown here. It is important to remember that two-core electronic cable is used only on double insulated appliances; three-core electronic cable is used on all items requiring an earth connection. Read the rest of this entry »
