Please read the disclaimer
before attempting any electrical work. If
you are uncertain then contact
a qualified electrician.
you are allowed to do yourself
- You may change
or repair a socket, light or cabling in
- You can add additional
spurs, lights or sockets to an existing
circuit unless it’s located in the
kitchen, bathroom or outside.
- You can install
or replace an electric shower, garage door,
cooker or gates as long as it’s on
an existing circuit.
- You may fit security
lighting or air conditioning to outside
lighting to the outdoor wall (unless a new
circuit is required).
- You may install
outdoor sockets if it’s a pre-assembled
must notify local building control for an
electrical inspection and test when:
- Adding a new circuit
to an existing installation
- Any electrical work
is carried out in a room where water is
present unless it’s a repair or replacement.
- Any outdoor work e.g.
garden sockets or lighting unless it’s
- Replacement of consumer
unit (fuse board/distribution unit)
- Installation of central
heating control wires.
- Installation of a socket
outlet that’s outside.
- If a fully qualified
electrician carries out any of the work
above then you do not need to contact local
- You should never carry
out any electrical work unless you are 100%
sure that the regulations you know are correct.
you are unsure contact your local building
control department for more information.
Electricity runs throughout
your house through the walls, underneath the
floor and in the ceiling to your appliances.
Cables that are used in
domestic appliances usually have an oval cross
section and have conductors inside called
cores. In newer cabling the live or phase
core is insulated with a brown sheath. The
earth core is bare and runs between them.
This is usually known as 2 core and earth
cable. Special 3 core and earth cable is used
in a 2 way light switch which has grey, brown
and black cores. Any or all of these cores
may be live. If the sheath is stripped from
one of the core cables then you must put green/yellow
earth cable over the earth core.
The Institution of Engineering
and Technology has made a change to its wiring
regulations that tell the new cable core colours
for any new fixed wiring in the electrical
installations in the UK.
The new cable core colours are referred to
as “harmonised” colours, and bring
the UK more closer to the European colours.
Any electrical installations made after the
31st march 2006 must use the new colours.
Flex is short for flexible
cord and is commonly used to connect pendant
lights and appliances to fixed wiring. It
will usually have 2 or 3 cores within the
white or coloured PVC sheathing.
All cores are coloured:
Altering existing installations
When it comes to altering
existing installations it may involve using
a mixture of old and new colours.
Two core and earth
When you connect old and
new cables at a socket or junction-box terminal
you must make sure you connect the correct
You must also fix the following warning notice
at the consumer unit or distribution unit.
Working safely with
Before you carry out any
electrical work you should take the following
- Turn off the main power
at the consumer unit (fuse board/fuse box/distribution
- Isolate the circuit
you are going to work on by taking the circuit
fuse out or switching of the circuit breaker
and locking it off. Tape the off button
down with a note saying you’re working
on a circuit.
- Check the circuit isn’t
live before working on it with a plug in
socket tester or a voltage tester for lighting
Once you have completed
the work replace the fuse/circuit breaker
and then turn the power back on. You should
never restore the power unit all the face
plates and covers are fitted back on.
Three core and earth
The connections that are
made in a two-way and intermediate light switch
are such that the circuit can be broken or
made at any switch point. The brown, grey
and black cores may all be live at a light
switch sometimes. They need to carry a warning
of brown PVC sleeve or tape.
Old to new connections
You must also fix the following
warning notice at the consumer unit or distribution
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