New light only works when old one is on.

[Wiggy1983]

I'm sorry about this, because I'm pretty sure this is a very common problem. Tried searching, but I'm not quite sure what I'm trying to ask. (If you know what I mean.)

I've just added a new light and switch exactly as per the How to ..... //www.diynot.com/pages/el/el032.php

I tapped into the existing spotlights using a junction box.

Trouble is the new light only comes on when the spots are on. This isn't quite what I was after. I take it this means I've taken the feed from a 'switched live??

I would really appreciate some advice from you guys on how to get round this.

BTW I've got Blue/Brown (Harmonised??) wiring.

Ta muchly.

 

[PrenticeBoyofDerry]

Try this link:
//www.diynot.com/wiki/electrics:lighting:lighting_circuit_layouts
If you have used a junction box this must be easily accessible for repair, inspection and test. Can not be left in a ceiling void with no access to it.

 

[Wiggy1983]

Thanks for the link.

Hmmm, I did have a look at that, but I'm still struggling a bit. However what I didn't mention was that the new switch is actually 3 gang replacing a 2 gang.

So, is the link and this diagram.......

.......trying to tell me that I can borrow a permanent live from the existing wiring at the switch?

Or am I taking rubbish?

Thanks again.

 

[EFLImpudence]

Where is the junction box?

 

[Wiggy1983]

It's in the loft, between two of the six spots.

 

[riveralt]

If your existing light switch is wired in a format similar to the one you have posted then the light switch is effectively acting as the junction box with a permanent live (loop) indicated at C and permanent neutral (loop) in the terminal strip. Switched lives leave the switch to the lamp.

If this arrangement was true for your spot lamps and you have changed the 2 gang switch for a three gang switch then you can take the power from the permanent live loop.

To do this make sure your new switch is wired as the old one. Then run a small piece of brown cable (1mm will do) from the permanent live common to the common on the third gang.

Then run T&E from the third switch up to your new light. At the switch use the brown as the switch live (L1) and connect the blue cable to the terminal block with the black (neutrals) in and also connect the earth.

At the new lamp connect the brown, blue and earth cables as marked.

 

[Wiggy1983]

Excellent! I believe I understand. Thanks very much.

This is a learning curve for me.

I'll get to it in the morning, and report back. To hopefully aid others.

I'm very grateful for your advice, cheers.

 

[Wiggy1983]

Big thanks to riveralt. You've earned some pictures. Heh.

Untitled

• Wiggy1983
• 6 Nov 2011
• 1

Untitled

• Wiggy1983
• 6 Nov 2011
• 1

As usual I was trying to make things harder than they needed to be! In the end it was so simple. But the best bit is that I now understand how it all works. I did wonder at the time why the Commons were joined like that, but it's all become clear now.

So thanks again.

 

[EFLImpudence]

it's all become clear now.

Glad you have seen the light