Weird wiring

LeeF&AJay · 2 Oct 2006

Hello, hope someone can help us. We've just moved into a house where there are two separate lights in the front room, controlled by a normal double switch. However, there are only 4 wires for both lights, ie switch 1: yellow goes to ~ and blue to L1. Switch 2: red folded over and going into both ~ and L1. This works with the double switch but when we try to use the same setup on a dual dimmer switch, nothing happens. Has anyone got any ideas? Sorry if this has already been posted by someone else. Cheers

breezer · 2 Oct 2006

more info

where has this "duel dimmer" come from?

LeeF&AJay · 2 Oct 2006

It came from Argos http://www.argos.co.uk/static/Product/partNumber/9829811.htm

fireman22 · 2 Oct 2006

can you explain more about switch 2 red folded etc

LeeF&AJay · 2 Oct 2006

ok, it's a single wire folded over, it is exposed at the bend and also at the end of the cable, as normal. The bent bit goes into L1 and the end into ~. Hope that makes sense

fireman22 · 2 Oct 2006

no think you are going wrong here somewhere, the red bent over would normally go in one of the C terminals with the end of the red in the other C terminal, it could never work across C and L1 of the same switch. So reds go to the ~ terminal with the yellow and blue as the switched lives. put the old switch back on and try first before trying the new switch

LeeF&AJay · 2 Oct 2006

This is a bit crude but may give a better idea:

This is how it was wired before we got here... it doesn't make sense to us but it works

fireman22 · 2 Oct 2006

yes got that as i said reds go to C terminals or ~ on dimmer yellow and blue are switched lives out

securespark · 2 Oct 2006

Try disconnecting all wires from the switch, having isolated first. Then use a choc block to connect (in turn) red to yellow, and red to blue. What happens?

HDRW · 3 Oct 2006

LeeF&AJay said:
This is a bit crude but may give a better idea:

This is how it was wired before we got here... it doesn't make sense to us but it works

Is this diagram accurate? You haven't swapped the bottom sequence of terminals round? You'll often find that the two switches' connections are arranged in two triangles, inverted with respect to each other, like this:

COM L1 L2

L1 L2 COM

And what catches people out is that they think that each row is one switch, but in fact the top COM is switching between the two bottom Ls and vice versa. So if this is how your old switch was, then you had the red going into the COM of one switch and the L1 of the other, so connecting the lights to the L1 and COM respectively will work.

If this is the case (check the old switch with some type of continuity tester), on your dimmer just connect the red to the two COMs and take the lights from the two L1s, and you've won!

Cheers,

Howard

LeeF&AJay · 3 Oct 2006

Hi HDRW, you're absolutely right, the sequence on our drawing was incorrect -- instead of each row representing one switch, the live wire crossed both. Because the live wire in our case was very short, we've had to get some extra electrical wire and attach it to the one coming out of the wall (using plenty of electrical tape!!), so that it would feed both switches on the dimmer switch. Thanks a lot everyone for your help

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Weird wiring

breezer

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