Electricity cable colour coding
If you’re undertaking any kind of work involving mains electricity, it’s vitally important (literally, a matter of life and death) to know how to connect the cables. Connecting them wrongly could result in electric shock, which can be fatal.
In the United Kingdom, the regulations that came into force on 1 January 2005 mean that all domestic cabling installed after that date has to conform to the following colour code:
- Live: brown
- Neutral: blue
- Earth: green/yellow
(In practice, the earth wire is usually bare; the person doing the work has to fit a length of green/yellow sleeving over any exposed parts of the wire)
This corresponds to the colour codes in the flex that’s been used for domestic electrical appliances for the last few decades.
As you’d expect, though, the vast majority of houses built before that date are still wired with cable using older colour coding. The cable will almost always be coded as follows:
- Live: red
- Neutral: black
- Earth: green/yellow (or green, in some very old installations).
So when making your connections, remember to connect only these together:
RED – BROWN – Terminal marked L
BLACK – BLUE – Terminal marked N
GREEN – GREEN/YELLOW – Terminal marked E or ⏚
