Always be wary of electricity. Here are the 12 most important rules.
1 Turn off the main switch and remove circuit fuses before doing any work on an installation.
2 Do not undertake any electrical job unless you are confident of your capability.
3 Carefully follow manufacturers’ instructions when given.
4 Buy only good quality appliances and use them only where and how they are intended to be used. This applies particularly to electric blankets, which should be returned to the makers every three years for inspection and testing. Never use an all-night overblanket as an under-blanket or vice versa. And never have an underblanket switched on when the bed is occupied.
5 Do not take portable mains-operated appliances into the bathroom or have socket-outlets installed there, except the correct shaver supply socket for use only with a shaver.
6 Keep flexible cords as short as possible and never run flexes under carpets, rugs or other floor-coverings.
7 Use the correct flex for each appliance and for the situation in which the appliance is used.
8 Make sure that all appliances having exposed metalwork are effectively earthed if not marked by the maker as being double-insulated.
9 Remove the plug from its socket before working on a portable appliance or lamp.
10 Do not keep a portable electric fire plugged into its socket when not in use or stand it against furniture or fabrics which would scorch or set alight if the plug were inadvertently replaced in its socket.
11 Do not let clothes and linen or other fabrics fall on to a convector, fan heater or storage heater where the build up of temperature may cause scorching and start a fire.
12 Do not knock nails or fix screws in walls and floorboards where there are likely to be cables.
What Electrical Terms Mean
- Volts — unit of electrical pressure.
- Amps — unit of electric current.
- Ohms — unit of electrical resistance. Watt — unit of electric power.
- KW —1 kW = 1000 watts.
- KWh — 1 kWh or one unit of electricity is consumed by an appliance at the rate of 1 kW in one hour.
- AC — alternating current as from mains electricity. The polarity + and — changes continuously many times per second according to the rated frequency of the current.
- DC —as from a battery. The poles 4- and — do not change.
- Hz — unit of frequency of an AC current. Volts, watts, amps and ohms are interrelated. Volts = amps x ohms. Amps = volts+ohms. Ohms = volts+amps. Watts = volts x amps (in a purely resistive circuit). Example: an electric fire is rated at 240 volts and has a 1000-watt loading. Current consumed = watts+volts = 1000240 = 4.166 amps. Resistance of element (heated): volts+amps = 240+4-166 = 57.609 ohms. If the heater is switched on for two hours, lkW x 2 = 2 kWh of electricity is consumed.