Warning: To complete electrical works you must comply with Electrical Regulations – Click here for more information.
Please also see our project on the New Wiring and Cable Colours.
Please also check the rules very carefully for ring mains and radial circuits. You are limited in the length of cable you are allowed to use in both circuits and long spurs could make you exceed the limit. If this is the case you are asking the circuit to use much more energy than the circuit is designed for. More energy = more heat and cables can catch fire. Part P of the new building regulations could involve a check on any additional circuitry by qualified electricians when you sell your home. This can affect your sale, you could be breaking the law and your house insurance may not be valid. Please be absolutely sure you know what you are doing and get all of your work checked by a qualified electrician.
Stripping Cables, Flexes and Wires
Stripping wires etc can be very easy. As with most jobs in all walks of life, it is much easier, and safer with the right tools. Electricians will use side cutters for all of the jobs you will see demonstrated below.
You will not have the ability, touch or experience to do this and a tiny little nick out of a cable, flex or wires insulation can be lethal as it will allow current to arc across wires. This will, if you are lucky, just lead to a short circuit which will trip the fuses, or, if you are not, start a fire which could kill you and your family.
We do not underestimate the danger of electricity at any level here at Diydoctor and strongly suggest that if you have any doubts about what you intend to do…Do not do it.
The images below show how to strip a cable. The cable shown is a 2.5mm two core and earth (see our cables project). First the cable is nicked through the sheath at the end. Get this nick in the middle.
Pull the nick apart a little and you will see the bare earth wire in the centre. Clamp the wire with the side cutters gently and, holding the end of the cable in your other hand, pull the wire through the insulation. This will tear quite easily.
For those with no experience its best to use pliers for this operation rather than side cutters as shown. Measure the connections you wish to make, add enough on to turn the wires over (see below) do not skimp on the length. "Stretching" cable to meet connections can mean they will pull out over time, don’t forget your house is moving all the time. It is better to have a little more than you need folded into a socket than too little.
Pull the sheath back and snip off having exposed the live and neutral wires CHECK FOR NICKS IN THE SHEATHING TO THE LIVE AND NEUTRAL.
Make absolutely sure any circuit you are working on is isolated before you attempt to make any connections.
Stripping flex for appliances is not quite as easy as stripping cable. Unfortunately we do not have the flex stripper shown here on sale in the toolstore but it can be bought in most DIY stores.
The tool allows the flex to be cut by using the left hand opening, the sheath stripped by using the centre opening and the individual wires stripped via the other. Again it must be stressed that this, as any other tool must be used very carefully as it is more than possible to nick the inner wires without realising.
The alternative to using this tool is to slice very carefully around the circumference of the outer sheath with a hobby knife. Apply enough pressure (with either the stripper of the blade) to just cut into the sheath. Then bend the sheath a couple of times until it splits and you can see the wires inside. Pull the sheath off.
This particular flex is for a light fitting, most appliance flexes will also have an earth wire.
Again, make sure you have measured the length of wire you need for connection without stretching the wires. Allow for the slight bend in a plug.
Now the wires can be stripped using the first kind of wire strippers above. The ends of them are now twisted together and can be doubled up if you like. For plugs a 7mm length of exposed wire is all that is needed to get the correct connection.
When you buy a new plug there is, 99% of the time a paper instruction plate slid over the plug points. Before you just throw this away have a read. Most people do not realise it, but on good quality plugs this paper actually gives the exact lengths of wire needed to get a perfect connection.
Not all plugs are exactly the same so even if you can read this one, do not be tempted to use the measurements for your own plug. Either read the back of yours, or measure it out.