Guide to connecting a new socket outlet to the power cables of a ring main, and fixing it to the back box or pattress in the wall.
Depending upon where in the circuit you are fitting the socket you may have one, two or three sets of conductors. This article assumes that the socket outlet is being connected as part of a standard ring main and there is no spur. You will, therefore have two cables at the socket outlet. If you are not sure whether this is what you have, consult a professional electrician for advice.
1. Switch off the power at the consumer unit for the circuit concerned. If you have removable fuses at your consumer unit, switch off the power at the consumer unit and remove the fuse for this circuit.
2. Strip both the cables ready for connection. Cut through the end of the outer sheath of the cable carefully using a pair of side cutters. Be sure not to cut into the insulation of the conductors.
3. Peel back the sheath to reveal the conductors and grip the end of the bare earth conductor with a pair of pliers. Draw the wire back through the sheath like a cheese wire.
4. Fold the excess back and trim with the side cutters.
5. Separate the conductors and trim the insulation of each back by about 1/2" with wire strippers. More on this can be found in our Cable Stripping Guide.
6. Insulate the earth conductors using the separately sold green and yellow sleeving. This should be cut to length and fed over the conductor so that about 1/2" is left exposed at the end to match the other conductors.
Connecting the cables to the socket outlet
7. Slacken the screw of the appropriate connection terminal. If you are fitting more than one conductor to a terminal, insert them alongside each other. Do not twist conductors together before inserting them into the connection as this may damage them and can also cause problems when testing circuits.
8. Insert the brown (old cable colour = red), live conductors into the hole in the terminal marked ‘L’.
9. Ensure that the conductor is fully housed and that there is no exposed wire showing. Fasten the screw and make sure the wire is firmly secured.
10. Repeat the process for the blue (old cable colour = black), neutral conductors, fixing them in the terminal marked ‘N’.
11. Repeat the process for the green/yellow, earth conductors fixing them to the terminal marked with the earth symbol.
Metal Boxes Only
12. If you have a metal box like the one shown here, an earth tail may be required. One must be fitted between a socket outlet and metal back box where both socket fixing lugs are adjustable. If this is what you have, cut a suitable length of the earth conductor from some cable of the same size as that used for the circuit. Sleeve this with green and yellow sleeving allowing ½” conductor to be exposed at either end.
13. Connect one end of this earth tail to the earth terminal provided at the back of the metal mounting box.
14. Connect the other end of this earth tail with the earth conductors secured to the terminal marked with the earth symbol on the socket outlet.
Fixing the socket outlet
15. Double check that all your connections are to the correct terminals, and securely fastened.
16. Carefully push the face plate back, gently folding the cables as you go, so that they sit neatly into the box.
17. Fasten the face plate with its retaining screws. Tighten the screws alternately to draw the plate back evenly.
18. As you tighten these, ensure that the face is level. One or both of the screw mountings will have allowance for a small amount of vertical adjustment which assists with this.