Adding lights and switches

It is a simple operation to add an extra ceiling light, controlled by its own switch, to an existing lighting circuit. If as in most modern homes the wiring is flat twin PVC-sheathed cable, it is likely the loop-in system is used, which means an extension can be taken direct from an existing ceiling rose.

In recently wired installations the circuit cable also contains an earth continuity conductor (ecc), which is looped in and out of an earth terminal in the ceiling rose. If your lighting circuits are wired on the junction box system — common until the mid-1960s — there should normally be one junction box for every light and its switch.

Loop-in extension

Drill a 13mm (fin) diameter hole in the ceiling at the new light position and another hole in the ceiling immediately above the new switch position. Any floorboards above will have to be raised, as will some along the new cable route to gain access above the ceiling. Switch off at the mains and remove the ceiling rose and pendant flex at the connecting light. Take care not to separate joined wires; if necessary use insulation tape to keep them together temporarily.

Take your coil of 1 sq mm two core and earth PVC-sheathed cable and mark ‘mains’ on the end of the sheath; push the end through the hole in the ceiling at the connecting light, leaving the existing wires protruding from the ceiling. Then pull through sufficient cable from the floor above (or in the roof space) to reach the position above the new light. Thread the cable through holes drilled in the joists, at least 50mm (2in) below the top of the joists, and pass the end of the cable through the hole in the ceiling, leaving about 300inm (12in) for connections at the new rose. Cut the cable at the old ceiling rose position, leaving about the same amount for connections.

Take the cable coil to the switch position and push the end through the hole in the ceiling. From above, run it to the new light and pass the end down alongside the first cable marked ‘mains’.

Mounting a new ceiling rose

If there is no suitable mounting for the new light, fix a piece of 100 x 25mm (4 x lin) timber between the joists just above the ceiling, having first drilled a hole in the timber to take the two sheathed cables. Cut the cable at the switch position about 1.37m (4ft 6in) above floor level, leaving about 300mm (12in) for connections.

Knock out the thin plastic in the base of the ceiling rose, thread in the two cables and fix the rose to the ceiling with screws 25mm ( I in) long. Strip about 50mm (2in) of sheathing from the end of the cable marked ‘mains’ and about 6mm (tin) of insulation from the end of the red and the black wire. Insert the bared end of the red conductor into one of the terminal holes in the live (centre) terminal and tighten the screw. Connect the black wire to the neutral terminal, using the middle hole. Push the cable slack back into the ceiling, making sure the end of the sheath will be within the rose.

Prepare the end of the other cable in the same way and connect the red wire into one of the other two holes in the live terminal. Slip a short piece of red PVC sleeving or insulation tape over the end of the black wire and insert this into the inner terminal hole of the two-hole (switch wire) terminal bank. Slip green PVC sleeving over the bare earth wires and connect to the earth terminal.

Now connect the pendant flex. Strip about 75mm (3in) of sheath from the end of a length of two core flex. Bare the ends and connect the brown to the outer hole of the switch wire terminal and the blue to the outer hole of the neutral terminal. Tighten all terminal screws and hook the flex wires over the anchor pieces: thread on the rose cover and screw it to its base. Connect the lampholder to the other end of the flex, using the same method as for the ceiling rose; if the unsheathed wires protrude from the cap, the flex wires must be shortened.

Connecting a switch

If the switch is to be surface-mounted, take the plastic surface box and knock out a thin section for the cable. Hold the box in position against the wall and mark the fixing holes. Drill and plug them to take No 8 screws. If the switch is to be flush-mounted you must use a metal knock-out box. The cable from the ceiling to the box can be fixed to the surface, using plastic cable clips spaced no more than 400mm (16in) apart or buried in the plaster.

The end of the cable is stripped and the conductors prepared as for a ceiling rose. The red wire, which is the live feed, is connected to the common terminal. The black wire, the switch wire, is enclosed in a short piece of red PVC sleeving or PVC insulation tape and connected to the L2 terminal. The earth should be enclosed in a length of green PVC sleeving and connected to the earth terminal in the mounting box. The switch is secured to its box by two screws supplied.

Replacing the existing rose

Replace the existing wires as before; if you had an old type ceiling rose, replace with a modern one with in-line shrouded terminals. Strip and prepare the end of the new cable as for the first ceiling rose. Connect the red wire to the centre terminal (alongside another red wire if there is no spare terminal hole), the black wire to the neutral terminal and the earth wire, with its green sleeving, to the earth terminal. Any existing unsleeved earth wires in the rose should be sleeved before reconnecting.

Junction box extension

After switching off the power, locate an existing, suitably placed junction box by lifting boards or checking in the roof space, unscrew the cover and examine the wires and terminals. The red live wire of the new cable is connected to the terminal having two or more red wires, the black neutral wire is connected to the terminal containing two or more black wires and the earth wire with its green sleeving, goes to the terminal containing earth wires. The remainder of the work is the same as when looping out of a ceiling rose to another rose.

Moving a light

When a ceiling light is to be moved, take down the existing pendant (having, of course, switched off the power) and pull back the cables into the ceiling space — taking care not to separate wires connected to any one terminal. Mark which of the two wires or sets of jointed wires were connected to the flex terminals, for it is from these the extension is made. Nail a piece of 100 x 25nun (4x I in) timber between the joists, about halfway down, and fix a four-terminal 5amp junction box to it. Drill a hole in the ceiling at the new position and lift boards and drill holes in the joists as necessary for the route of the new cable from the junction box to the light. Run a length of cable from the junction box to the light and pass the end through the hole in the ceiling. Connect the live wire to the switched live rose terminal, and the neutral and earth wires as before.

At the junction box, connect the existing wires to the box terminals. If the existing light was a loop-in ceiling rose, all four terminals in the box will be used. Otherwise only two, plus earth, will be needed. Prepare the end of the cable and connect the red to the single wire which was connected to flex. If this is a black wire, enclose the end in red sleeving or PVC-insulated tape before connecting it to the junction box terminal. Connect the black wire to the terminal now containing one, two or more black wires and connect the earth, with its green sleeve to the terminal containing the earth wires; if the circuit has no earth, connect it to a spare terminal. Replace the box cover.

Fitting an extra light

When you need an extra light that is to be controlled by an existing switch, follow the instructions given for moving a light, except that instead of using a junction box you leave the original light in position, install a new ceiling rose and connect the new cable to the existing ceiling rose terminals carrying the flex wires.

Fitting an extra switch

Adding a second switch to a lighting point, such as at the end of a hall or at the back door to provide another switch in a kitchen, not only adds to your convenience but probably helps you to save electricity. Replace the existing one-way switch with a two-way switch, install a two-way switch in the second position and link the two switches together by fitting a lsq mm three core and earth PVC-sheathed cable.

If the existing switch is the modem square plate mounted on either a plastic surface box or a metal flush-mounted box, remove the existing switch, push the end of the new cable into the box through the existing grommet, run the cable up the wall through the ceiling, under the floorboards (or roof space) and down through the ceiling to the second switch position, where you fit either a surface or flush-mounted recess box.

Three terminals A two-way switch has three terminals — Common, LI and L2. The two existing wires disconnected from the one-way switch are connected to terminals LI and L2, although it does not matter which goes to which terminal. The three core and earth sheathed cable has three insulated wires: red, yellow and blue. The red wire goes to the Common terminal, the yellow wire to terminal LI and the blue to L2. The earth wire in its green sleeving is connected to the earth terminal of the box. At the second switch there are only three new wires plus the earth. The red wire is connected to the Common terminal, the yellow to LI and the blue to L2, and the green sleeved earth wire to the box’s earth terminal. Arrange the wires neatly in each box and secure the switches with the screws provided with the fitting.

Fitting a cord switch

Cord-operated ceiling switches are made in one and two-way versions; so in a bedroom, for example, you can fit a switch on the ceiling above the bed-head as well as the normal switch by the door. The three core cable is passed down through a hole in the ceiling instead of down the wall and the switch fixed to the ceiling. If necessary mount the switch on a piece of timber fixed between the joists, as already described. The connections are the same as for a wall switch.

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