Mark the Position of New Socket
Hold the metal box of the socket against the wall and draw around it in pencil. Next, mark the chase or channel running up to the socket from the skirting board to the drawn outline. Use a masonry drill and bore a series of holes just inside the lines to the required depth of the recess.
Cut the Masonry
Using a bolster and cold chisel, hack away the plaster down to the brickwork. Cut away the brickwork to the depth of the drill holes so that the socket box lies flat with the plaster. Fit the box in the recess.Marl< the wall through the fixing holes and drill the wall for screw plugs.
Wiring the Socket
To accommodate the cable, you’ll need to knock through one or more of the blanked out holes in the socket box where it lies over the chase of the channel dug in the wall. Fit a grommet into each knockout hole to stop the sheath from chaffing. Feed the cable into the box and screw the box to the wall.
Where a single cable is involved, strip off the outer sheathing of the cable, separate the conductors and connect them to their correct terminals. Black to neutral – N; red to live – L; and earth – which you must insulate with a length of green/yellow sheathing – to earth – E.
If necessary, fold over the bare ends of the wires so that they don’t protrude from the terminals. Bend each conductor so it fits into the box. Attach the faceplate and tighten the fixing screws gently until the plate fits firmly against the wall or pattress of the socket.
Connecting to an Existing Socket
Having fitted the new socket and wired it, you will need to run a cable – the spur cable – from this new socket to an existing one. Switch off the power and remove the existing socket. You may have to enlarge the pattress of this socket, or knock out another hole to accommodate the spur cable. Feed the spur cable into the pattress, strip away the outer sheath of the cable and separate the individual conductors. Twist the bare ends of the each conductor in the spur cable with the matching conductor ends on the ring circuit. Then insert the ‘doubled’ conductors into their appropriate terminals: red – Live (L); Black – neutral (N), and Green/yellow – Earth (E). Replace the socket, turn on the power and test the new spur socket.
Connecting to a Junction Box
To connect a spur socket to the ring circuit you will need a 30-amp junction box with three terminals. This will have knockout entry holes for the cable or a rotating cover that blanks off unused hole. The cover must be screw fitted.
Turn off the power to the circuit. Lift a floorboard close to the new socket and in a position where you can connect to the ring without stretching the ring circuit cable. Make a platform for the box by nailing two battens near the bottoms of two joists and then screwing a strip of wood between them. Loop the ring circuit cable over the platform. Remove the cover of the junction box and screw the base to the platform. Break out two entry holes. Rest the ring circuit cable across the box and mark the amount of sheathing you need to remove. Slit the sheathing and peel it away from the individual conductors. Don’t cut the live (red) and neutral (black) conductors; just slice enough of their insulation away to expose a small section of bare wire that will fit in the terminal.
Cut the earth wire – this will be the bare wires, which now need sleeves of yellow/green on the two cut ends. Take out the screws from the terminals and lay the wires across them – the earth wire in the middle terminal, and the live and neutral wires on the ends. Push the wires in securely with the tip of a small screwdriver. Now run the cable of the newly installed socket to the junction box. Cut and prepare the ends of the wires and break another entry hole in the junction box to accommodate them.
Make sure now that the wires are matched up according to their colour, so that the live, neutral and earth wires share the same terminals. Replace the fixing screws and check that the wires are secure in their terminals and the cables are snug in their entry holes to the junction box and that their sheathing runs right into the junction box.
Fit the screw cover on the box and then, to take the strain off the terminals, clip each of the cables to a nearby joist. Switch the power back on and test the new socket. Replace the floorboards. It is a good idea to mark clearly on the floorboards the location of the junction box and cables underneath.