DIY Tips on How to Connect and Replace an Electrical Wall Socket

by Steve on August 12, 2011

This article gives some information and DIY tips on replacing and connecting wires to 13 amp electrical wall sockets including some relevant electrical safety.

Safety Warning

If you’re not a trained electrician I would advise you proceed with caution before attempting any type of DIY electrical work. Installing electrical equipment and working with electricity can be very dangerous if the correct procedures are not followed. Many DIY electrical jobs such as replacing sockets and switches are fairly simple home improvement jobs but sometimes they can turn out to be more than you bargained for, especially when you’re faced with an unexpected amount of wiring or find that the cables or sheathing have been cut too short or damaged.

Tools

You’ll need a good quality electrical terminal screwdriver and may also need a sharp knife, pliers and wire cutters or strippers. A plug-in electrical tester is also essential.

Circuit Protection

We are presuming that the existing wiring to the plug socket is in good condition, the correct size and is protected by the correctly rated fuse or circuit breaker at the fuse board or consumer unit. These are electrical wiring basics that electricians are trained to assess, and again if in doubt please contact an expert or even consider asking an electrician to carry out an inspection of your home’s electrics. Most electrical installations will have been tested at some time and you may be able to refer to documentation to verify that everything is in order.

Safe Isolation

Never work on a live circuit. You must follow basic electrical testing procedures before removing the old socket outlet.  This involves checking that the wiring connections are correct before you begin by using a plug-in electrical tester. If the tester indicates that there is a problem such as no earth connection or an earth fault I would strongly recommend that you don’t proceed any further and seek the advice of a qualified electrician.

By using a socket tester you are also proving that there is voltage at the socket and that it is ‘live’. If all is good you are ready to isolate the supply to the circuit.

Locating the Circuit

It’s a good idea to reduce the electrical loading on all the circuits of the installation before attempting to isolate circuits. This will prevent ‘arcing’ or ‘flashing’ when pulling out fuses and turning off breakers of circuits under load.

With your plug-in socket tester showing that the socket is ‘live’ and correctly connected you can now isolate the circuit at the fuseboard. Finding the correct fuse of circuit breaker can be a problem when the circuits are not labeled. A much safer and sure fire way to isolate an electrical circuit is to turn off all the circuits and the main switch to the whole installation. This will ensure that no power will be present when you remove the socket faceplate.

If you want to turn off only one circuit make sure that everyone else in the building knows that the power will be cut and work your way through the circuits, turning them off one at a time until the socket tester shows no voltage. You may need the help of another person to let you know when this happens. Some socket testers have an audible sounder which is useful for this purpose.

At this stage an electrician would perform a ‘Lock Off’ on the circuit. This involves placing a notice at the fuseboard, putting the fuse in his pocket or padlocking the breaker so that no one else could turn it on whilst the work is being carried out.

Removal of the Socket

The socket faceplate is normally held in place by 3.5mm accessory screws. Remove these and the existing socket should come away from the wall. If the faceplate is stuck by wallpaper or paint you can neatly release it by running a sharp knife around its perimeter.

Disconnection

Take a look at the connections and socket terminals on the back of the old socket and assess if you want to continue. It should be a straight forward process to simply loosen the terminal screws and re-connect the new socket. As an experienced electrician I would always check again that the circuit is dead before I touch the bare ends of any cabling by testing across the socket terminals with my probe voltage tester.

The wiring to the terminals should be:

  • ‘L’ Live terminal- Brown or Red
  • ‘N’ Neutral terminal- Blue or Black
  • ‘E’ Earth or Ground terminal- Green & Yellow or Green

If you’re in any doubt at this stage then replace the socket and seek the advice of an electrician!

Re-connection

When the old socket has been removed it’s a good idea to check the ends of the copper wires to make sure that they haven’t been weakened by crushing or badly squashed by tightening of the terminal screws. A weakened wire can break when re-connected or cause a high resistance joint which could lead to overheating when under electrical load. If required and length of cable permitting, cut off any damaged ends of cable and strip back the sheathing ready for re-connection. Generally a socket installed as part of a ring main circuit will have a pair or even three cables at each electrical outlet. In these cases a regular socket outlet terminal will only accept the wires if they are not bent or twisted. If there is only one wire to each socket terminal it’s usually good practice to strip the sheathing back further and double over the exposed copper. This makes a better connection under a terminal screw. Connect the coloured wires as described above and tighten the screws.

Re-fitting and Testing
Once the new socket has been re-connected it can be fitted back to the wall. Be careful not to damage the cables against the back of the mounting box as you push it back to the wall. Also make sure the cables are clear of the fixing screws as you screw them into their threaded holes.

Insert the socket tester, re-energize the circuit and check for correct wiring.  The new socket should now be safely  installed and ready for use. Well done!

An electrician would now carry out an Earth Loop Impedance Test at the socket to verify the connections and earthing are correct.

Additional info:

Fuseboards

If your electrical installation has an old rewirable type fuseboard, then the chances are you won’t have RCD protection.

RCDs give added protection against electric shock and can prevent fires from occuring where cables are degraded or damaged. Electrical regulations now require them on most circuits, especially for all sockets and lighting circuits where metalic fittings and switches are installed. For your household’s safety I would strongly recommend the installation of RCDs and the replacement of old rewirable type fuseboards.

Contact your local qualified electrician for advice on this matter. If you live within a 20 mile radius of Bedford I would be pleased to give a quotation- SPK Electricare.


{ 1 comment… read it below or add one }

duncan laughlin January 11, 2012 at 20:32

dont diy get a qualified full term spark.

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