Power points
Since the ring circuit can carry as many socket outlets and fixed appliances as you like, within the restraints of total possible loading, it’s usually possible to have sockets wherever you need them at relatively little extracost. And, ifyou plan your sockets effectively, they can all be installed at a height to suit the piece of equipment with which they will usually be used – 150mm from the floor (or any other surface – such as the top of a sideboard) is the minimum height; maximum height should be within reach of all the adults in a household.
There is a danger that a scheme, tailored in this way, to particular pieces of equipment, will work with only onearrangement of furniture. So it’s worth thinking about alternative positions too, perhaps installing sockets where they’ll be concealed by the present position of a piece of furniture (and will therefore remained unused), but are likely to be accessible, if the furniture is rearranged. All sockets should be easily accessible when they are in use so that equipment can be switched off and unplugged without trouble.
Apart from a whole new circuit (which might be the best solution if your wiring is old or if you want to install equipment which draws a heavy current), it’s possible to get extra sockets by changingsingle socket outlets to doubles, by installing more sockets on the ring or by adding a spur to the ring.
Before adding additional sockets you must make a careful examination of the wiring. There are limitations on adding sockets to spurs from the ring circuit or to a radial circuit . To ignore these restrictions is to risk overloading the circuit.
You can tell whether a socket is on a spur by inspecting the connections. Turn off the power at the mains and ease the selected socket from the wall by undoing the screws in its face plate. Behind it is the mounting box containing up to three cables.
One-cable sockets are either on a
You may be surprised to realise how many pieces of electrical more-or-less fulltime, other pieces of equipment are portable or can equipment you have. Many things will need to occupy a socket ‘borrow’ a socket when they need an electricity supply.
Power points
spur or on the end of a radial circuit. Two-cable sockets can either be on a ring or be an intermediate socket on a spur or radial circuit. Three-cable sockets usually indicate a spur has already been taken from the ring at that point but they may also be a sign of incorrect wiring. Either way three- cable sockets should be avoided.
It may be necessary to check the layout of a circuit further. The best way to do this is with a circuit continuity tester. With the mains off, disconnect all appliances from the circuits and the two live conductors from the socket terminals. Use the tester to link these two conductors; if the tester indicates continuity, the socket is on a ring circuit. If it does not, the socket is probably on a spur or radial circuit (though it may be a broken ring or, of course, a damaged testing device and both these will need investigating.
spur or on the end of a radial circuit. Two-cable sockets can either be on a ring or be an intermediate socket on a spur or radial circuit. Three-cable sockets usually indicate a spur has already been taken from the ring at that point but they may also be a sign of incorrect wiring. Either way three- cable sockets should be avoided.
It may be necessary to check the layout of a circuit further. The best way to do this is with a circuit continuity tester. With the mains off, disconnect all appliances from the circuits and the two live conductors from the socket terminals. Use the tester to link these two conductors; if the tester indicates continuity, the socket is on a ring circuit. If it does not, the socket is probably on a spur or radial circuit (though it may be a broken ring or, of course, a damaged testing device and both these will need investigating.
A double for a single
Like single sockets, double sockets have their terminal connections for the cable ends in the middle of the back of the plate. So provided there is sufficient cable all that needs to be done to exchange a single socket for a double is to replace the single box with a double one and install the new double socket.
Whether the existing box is recessed into the wall or surface- mounted, the easiest way to make the change is to install a new surface- mounted double box – there are special boxes 20mm deep sold for this purpose. Any existing surface- mounted box would of course have to be removed, but a recessed one could be left in place.
Mount the new box so that it is plugged into the wall each side of the old box—beware of buried cables.
If there isn’t sufficient slack cable, or if you want the new double socket to be flush with the wall, the job will involve removing the existing box; making or enlarging the hole in the wall to take the new double box; fitting the new box and making good. It’s best to do this when you’re redecorating anyway.
More sockets on the ring
Sockets can be added to a ring circuit at any convenient point by turning off the supply, finding and cutting the cable, installing the socket and connecting as usual. The difficulty with this method is that there is rarely enough slack in the cable to allow it to be drawn into a new mounting box and the cable must never be stretched or pulled. For this reason a spur from a junction box inserted into the ring or an existing socket is best.
EXTRA POWER POINTS
CONNECTIONS CHECKLIST
These details should be checked each time you connect a socket, switch or anything at all. Full details of Electrical work are given . • switch off at the mains
• always fit grommets in the knocked-out holes in mounting boxes.
• remove the sheath from cable within a box or fitting only
• aim to leave virtually no bare conductor exposed once the connection has been made • protect the bare earth
conductors with green and yellow sleeving and connect to earth terminal
• connect red conductors to live terminals
• connect black conductors to the neutral terminal
• double-check connections • shape the connected
conductors to fit comfortably inside the box
If in doubt don’t middle
E°
Single socket outlets— Double socket outlet and switched and unswitched. metal box for recessing
