Dimmer install

[rvp]

Hi,

I want to change a single on/off light switch to a dimmer which i have bought but there is two light switches controlling the one light, is it possible still?

I have had a look at the existing switch and it has 1 red and two black wires one saying common and an Earth.

The dimmer is metal so do i leave the Earth in the backbox and connect a wire to the metal dimmer?

The dimmer has L1 L2 and a cross like symbol along with a Earth point.

Any ideas?


Cheers

 

[RF Lighting]

Your old switch will be labelled L1 L2 and common or com.

You new switch has L1 and L2. Transfer the wires from L1 and L2 on your old switch to your new switch.

The wire in common on the old switch goes to the squiggly line with an arrow through it terminal on the new switch.

You should install a link of earth wire from the earth terminal of the new switch to the earth terminal in the backbox, and connect it in with the existing earth wire.

Take a photo or two before you start, and label all the wires up carefully. That way if you go wrong, we've a much better chance of helping you put it right.

 

[rvp]

Your old switch will be labelled L1 L2 and common or com.

You new switch has L1 and L2. Transfer the wires from L1 and L2 on your old switch to your new switch.

The wire in common on the old switch goes to the squiggly line with an arrow through it terminal on the new switch.

You should install a link of earth wire from the earth terminal of the new switch to the earth terminal in the backbox, and connect it in with the existing earth wire.

Take a photo or two before you start, and label all the wires up carefully. That way if you go wrong, we've a much better chance of helping you put it right.

Thanks for the reply. I thought it would be straightforward however it's the L1/L2 that has got me confused, no where whatsover can i see this labelled on the old switch! only Common is labelled.

 

[RF Lighting]

Can you post a photo of your old switch?

There should be some sort of label for each terminal.

 

[rvp]

Can you post a photo of your old switch?

There should be some sort of label for each terminal.

I'll try and get one up later just got the little 'un running about at the moment!

 

[rvp]

Pic as promised

View media item 56317
Now the single Red has Common stamped next to it and the others have nothing.

I'm thinking the Red and Black that are on one side willgio into L1 and L2 in the new switch and the single common will go into that ~ symbol.

Good guess or what?

 

[Scoby_Beasley]

Mark the red common (top) with a felt pen. That'll distinguish it from the other red. Put the other red and the black (which should have a red sleeve around it as it's a switched live, not a neutral) into L1 and L2 and you should be good to go.

Now. Where is this light switch? If its in your hall / landing make sure you turn off all the mcb's for lighting circuits in your fuse board/cu to swap the switch. Better still, turn your Main Switch in the cu off before touching anything.

 

[rvp]

Mark the red common (top) with a felt pen. That'll distinguish it from the other red int the com . Put the other red and the black (which should have a red sleeve around it as it's a switched live, not a neutral) into L1 and L2 and you should be good to go.

Now. Where is this light switch? If its in your hall / landing make sure you turn off all the mcb's for lighting circuits in your fuse board/cu to swap the switch. Better still, turn your Main Switch in the cu off before touching anything.

Cheers... so i was right then

Light switch is in the living room and i always turn everything off at the mains plus i pull the fuse out too, never be too careful with electrics.

 

[rvp]

Oh yes nearly forgot, i haven't any Earth wire knocking about but have a extension reel i don't use, can i trim some wire off pop some sleeving on that
and use it for the Earth from Metal dimmer to back box?

I know it's a bit of an odd way of doing it!

 

[Scoby_Beasley]

Strip a bit of the outer cover off the flex, cut a piece about 3 1/2" long of the earth (cpc), leave the green yellow insulation on that it already has, trim back 1/2" to 5/8" each end, twirl, double over, insert to earth tags on back box / dimmer and tighten, tug test, jobs a good 'un.