Loop lighting wiring

24 Jan 2006
Reaction score
United Kingdom
I am trying to wire up the loop lighting in my ceiling to a new junction box but have run into trouble. There are 4 cables, 3 of which are marked up:

1) 'Feed' (which I am presuming should be the electicity source cable)
2) 'To Light' (which I am presuming is the cable to the other light in the circuit)
3) 'SW' (which I am presuming is the cable to the wall switch)

I have wired them as such to a 3-3-2 jucntion (as per the diagram here - http://www.diydoctor.org.uk/projects/images/lightingexplained.jpg )but it is not working.

I am unsure of the purpose of the 4th cable but when I wired it as a loop (ie red in live loop section, black in neutral) the lights were permanently on with the switch not affecting it.

Would welcome any ideas!


Sponsored Links
If I've understood you right, the lights that you want to switch off aren't at the junction box. If that's the case, this fourth cable represents the two wires coming off the bottom of your diagram, so you need to connect them to neutral and switched (not permanent) live.

Don't forget the earths...
Thanks for the response, I probably wasn't too clear about the 4th wire. It is a heavy duty cable like the other three coming out of the ceiling and should connect to the junction box but I'm stumped as to what it does as it seems like one cable too many.

I have a normal cable (that's number 5 in this case) that is connected as you directed and per the diagram to a light fitting.

Sponsored Links

If you connect this cable four to permanent live and neutral, and your lights come on, then it must be connected to the live and neutral of your lights.

Any chance of a picture ?

DIYnot Local

Staff member

If you need to find a tradesperson to get your job done, please try our local search below, or if you are doing it yourself you can find suppliers local to you.

Select the supplier or trade you require, enter your location to begin your search.

Are you a trade or supplier? You can create your listing free at DIYnot Local