3 Gang dimmer

[Greenlight]

Hi

This is my first time so please bear with me!!

I have a 3 gang light switch (one way) which I want to replace with a 3 gang dimmer switch. The switch controls two wall lights, two spotlights and a light by the woodburner.

When I removed the light switch I was rather confused.... I have uploaded an image of the switch as it is currently connected. I have also uploaded an image of the switch I have bought.

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Can anybody help with how I should wire this?

Many thanks

 

[Spark123]

It looks like the existing switch has 2 holes for each common whereas your new switch only has one per common - not an issue tho.
It looks like the cable which is on its own on the left hand side is the supply cable - this red one goes to common on the first switch. You then need to loop this common across to the next, then onto the 3rd common.
The other 3 reds will go to the 3 L1 terminals.
You'll also need to loop the earth to the earth terminal on the switch plate as it is metal.
You could do with a deeper back box too.
3 gang dimmers usually fit double back box anyway - can't tell from your pic.

 

[ericmark]

You have 5 cables which are:-
1) Feed in and red goes to com
2) Feed out and red goes to com
3) feed to lamp 1
4) feed to lamp 2
5) feed to lamp 3
The original switch give you two terminals on each com so easy to link but new switch gives single terminal so either two wires in one hole or a terminal block like used in the neutrals all com connections need joining together with links.

The lamps go to L1

 

[securespark]

Cor! Haven't seen a Crabtree switch like that since the mid 80's!

They had spring-loaded terminals: push the red lever and the terminal opens up, release and it clamps the conductor.


Looks like there's a feed in at one common and a feed out at the other, then linked through.

 

[Greenlight]

Thanks Chaps for that.....can I just be clear about the common wires?

On my current switch I have two common wires....I am guessing one in and one out??

Do the other three red wires control the lights?

The new switch (incidentally a two way which I did not need!) has a slot for a common on all three switches? Do i feed the common wire into any of these and feed out of the same one?
Or do I feed into the first one, loop a wire into the second and then the third and attach the other common cable to the last switch...in effect making a chain?

 

[ColJack]

Do the other three red wires control the lights?

yes

Or do I feed into the first one, loop a wire into the second and then the third and attach the other common cable to the last switch...in effect making a chain?

yes, that one..

 

[sparkybird]

I think you'll be lucky to fit the dimmer switch as you have neutrals at the switch and only a 25mm back box. If you want to have a go, try and reduce the length of conductors to give you more space and be careful about the postion of the neutral connector block. Don't be suprised if the dimmer gives up after a while because of over heating.....

If it were me, I'd change the box to 35mm to be on the safe side.

SB

 

[Wooshzz99]

In 25 years I have never seen a 3 gang dimmer made to fit a single box??

 

[Steve]

Looking at the spacing of the dimmer modules, I think its a double faceplate.

He's got to chase the wall for a bigger backbox, so he might as well go deeper.

 

[Greenlight]

Cheers Everybody for your advice

I have bought a new back box when I bought the switch.....but thanks again for the tip.

I'll be back if I have any more problems.

I have to say...this is a very good site!! I will be using it again...I have just moved into a house so DIY will be with me for some time!!

 

[LiamPope]

Shame they just cut the cpcs on the cables to the light fittings instead of linking them to the loop in and out cpcs. Would have been about 1 minute's extra work. Make sure your light fittings are all class 2 - i.e. don't require an earth!

Liam

 

[ColJack]

talking of cpc's, don't forget to put an earth wire between the earths on the backbox and the dimmer front plate if it's going to be metal.

 

[ban-all-sheds]

They had spring-loaded terminals: push the red lever and the terminal opens up, release and it clamps the conductor.

Ah - that'll be why the COMs have two entries - you quite often need to link COMs, and with that type of terminal you can't get 2 conductors into the same one.

 

[Steve]

What about 2 way switching? where L1 and L2 would have two cores in each?

 

[ban-all-sheds]

Is it a 2-way switch?