Would like to wire in an extra light but

[Justins85]

Hi! Google brought me to your shores so hoping you can help!

In my utility room there is a double switch, one switch is for the out side light, the other isn't connected to anything. I want to put a light in the utility room but when I opened up the light switch there is only 2 wires (brown and blue).
It turns out the light has be fed the power then another twin core cable going to the switch. Don't know if this is normal or cheating etc !

Any way how do I get that 2 core cable to operate a light seperate from the outside light? I can't get another power source and the feed for the out side light is not accessible.

 

[riveralt]

Your current arrangment only gives you a live, switched live (and an earth - I hope) at the switch. There is no neutral at the switch. This is normal.

To utilise this switch to provide an independant lamp to the utility room there are a number of options - however they will all involve bringing an additional T&E cable to the switch.

Find the nearest lighting power source (ceiling rose - junction box with live, neutral and earth) to where you want the new lamp and run a 1mm T&E cable from the power source to the new ceiling rose connecting the brown live loop terminal (normally the centre 3) , blue neutral loop and sleeved earth to the appropriate terminals.
Then connect your cable from/to the switch at the ceiling by putting the brown cable to the ceiling rose live loop and the blue cable (with brown sleeving) to the terminal with the brown cable that goes to the lamp itself.
At the switch put the brown cable into common and the blue with brown sleeving to L1 - earth should be connected to the backbox.
As I said there are other options including changing the functions of the current switch cable and or having both the ouside light and utility room light come on/off at the same time.
Have a look a wiki...
//www.diynot.com/wiki/electrics:lighting:single_way_lighting

 

[ban-all-sheds]

Who builds a utility room with no lighting in it?

 

[Justins85]

Sounds like making both lights work together is easiest solution.



And as for a utility room with no light... I don't know who built it but they need a slap

 

[Justins85]

Oh and I couldn't see an earth!? The switch is a plastics outside job for some reason

 

[ban-all-sheds]

There should be one in the cable. There's nothing functional to connect it to in a plastic switch and box though, so even though all half-way decent ones provide a terminal to park it in, numpties sometimes just cut it back.

The problem with that is that if you fit a metal switch you can find you're stuffed if there isn't enough slack, and also the sort of numpty who does that is the same sort who will cut it back at light fittings which don't need an earth, and then all of a sudden you find that your entire lighting circuit has no earth continuity you can rely on.

 

[riveralt]

Sounds like making both lights work together is easiest solution.

But you will still need to either run a T&E cable from the light switch to the new ceiling rose or run a T&E cable from the outside light/power source to the new ceiling rose.
If you can do both of these then you might as well do a proper job and have the lamps on separate switches.

 

[Justins85]

Hmm I'm going to have a good look at what I've got over the weekend and make a decision.

Thanks chaps, I shall be back with a better explanation and more questions no doubt!