Light Socket Wiring Query

[L Reid]

Hi Folks,

Due to some of the electrical 'eccentricities' I've found since moving in (the latest being wire wool packed behind light fitting wiring), I thought I'd run this past the resident guru's for a second opinion.

In our livingroom we have a centre light and some wall lights. The main livingroom light is a 2 gang switch, however both switches on it appear to have been wired like a mini 2-way switching circuit. Flicking one switch turns all the lights on, flicking the other switches them off.

With the switch cover off, there are 4 wires. Red, blue, yellow and earth. The back of each switch has the following connections : Com, L1 and L2. The wiring is as follows (earth is earthed to the mounting box): red - SW1 Com blue & yellow - SW2 Com

The wiring in between is: SW1 L1 connected to SW2 L1 by a short cable SW1 L2 connected to SW2 L2 by a short cable

Diagram (note L1 and L2 are acually at the same height on the switch. --- denotes connecting cable):

SW1 Com (red) SW2 Com (blue/yellow)

L1 -------------------------- L1 L2 -------------------------- L2

I have establised that the blue is (I believe) the switched live for the centre light and yellow is the switched live for the wall lights. I want to wire up this socket to give independant control over the ceiling light and wall lights (rather than having both come on together). To do this I think I should connect the live to SW1 Com1, with a linked cable from SW1 to SW2 Com. Then I should connect the blue to SW1 L1 and the yellow to SW2 L1. Before I proceed, is this correct? If not, what would be the correct way to do this?

Many thanks,

Leigh (fingers crossed for ASCII diagram...)

[Chris Oates]

Really !!!!! That's an arsonists trick

[Frisket]

If you're certain that the red is the live wire then yes, linking it to both commons and using the blue on one switch and yellow on the other sounds right. HTH, Richard

[L Reid]

Gave me a surprise when I was polyfilla'ing around it. Had about 2 seconds to contemplate what it was before some strands got into the dodgy wiring it was wrapped around then tested my MCB's for me. Still went with loud bang and some flames though.

[BigWallop]

The Live (red) should be connected across the COM (common) terminals on both switches, then the Yellow should be connected to the L2 of one switch and the Blue to L2 of the other. You shouldn't need anything else between them.

Make sure you have the correct wiring configuration by touching the Blue to the Red, then touch the Yellow to the Red, and see which light fittings they each control.

[L Reid]

I ended up wiring pretty much as above, but used the L1 terminals of each switch for the yellow and blue rather than the L2 switch. Live accross both COM terminals. I did this as L2 was connected to COM when the switch appeared to be off, so connecting to L1 meant the switch looked like it was on when the lights were on, if you follow me. No idea why they were wired in the original arrangement though. I suspect the original owner got fed up with trying random combinations to get things working.

Cheers!

Leigh

[BigWallop]

This type of switch is called Two Way, and it works by making the L1 terminal connect to the Common terminal when the switch is thrown one way, and then connects the L2 terminal to the Common when the switch is thrown the other. So you can turn the switch upside down and connect the Blue and Yellow to the L1 and L2 terminals, respectively, and the switch will still look as though it is wired correctly.

I know what I mean. :-))