Dimmer Switch

[Rredwin]

I want to replace a one gang light switch with a dimmer switch. When i unscrewed the existing light switch, I found a lot more cables than I was expecting and none were wired in a way that made sense for the new switch. Any thoughts? Photos attached

 

[EFLImpudence]

You will need to put the blue wires in a separate connector block - that is just a terminal to 'park' the neutrals.

Then transfer the two wires in Com on switch to L1 on dimmer,
and wire in L1 on switch to wavy line on dimmer.

 

[Rredwin]

Thank you for a quick response!

What's the deal with a separate connector box? Is it something I can do myself it is that asking for trouble?

 

[DaveHerns]

You'll need to connect the earth to the front of your new switch

 

[stillp]

What's the deal with a separate connector box?

Connector block, not box, i.e. a piece of 'choc'block. You can do it yourself, there should be enough room in the back box.

 

[ban-all-sheds]

 

[Rredwin]

Thanks for all the responses. Why do I need to 'park' the neutrals? Are they not needed for a dimmer switch?

 

[ianniann]

Thanks for all the responses. Why do I need to 'park' the neutrals? Are they not needed for a dimmer switch?

They're not needed for this dimmer switch. Some dimmers use a neutral, but they aren't that common.

 

[rsgaz]

Why do I need to 'park' the neutrals?

Because they are already 'parked' in your picture. A normal light switch just has COM, L1 and L2....

...but you have a particular brand(which escapes me at the moment) that provides a terminal to join the neutrals together. It does not do anything in terms of the operation of the switch.

Gaz

 

[Rredwin]

Ah right! I think I'm getting somewhere now.

So Loop is just a terminal for the neutral.

COM is for the voltage sent to the switch and L1 is for the actual light?

And I assume L2 would be for a second light if I had one?

 

[rsgaz]

And I assume L2 would be for a second light if I had one?

No, the switch has two positions...

• COM is connected only to L1
• COM is connected only to L2 (ie, off in normal wiring)

It is used for when you have a light that can be turned on and off by more than one switch.

Gaz

 

[ban-all-sheds]

.

 

[ban-all-sheds]

I found a lot more cables than I was expecting and none were wired in a way that made sense for the new switch.

Why do I need to 'park' the neutrals? Are they not needed for a dimmer switch?

I assume L2 would be for a second light if I had one?

DIY electrical work isn't compulsory, but if you choose to do it you should reflect on the fact that unlike dodgy decorating, where runs in paint and bubbles in wallpaper won't kill you, or dodgy carpentry, where a wonky book case won't start a fire, electricity takes no prisoners, and you really, really ought to spend some time learning how things work if you want to fiddle with them.

• http://www.google.co.uk/search?q=electrical+circuits+(basics+OR+101)
  
• http://www.google.co.uk/search?q=uk+house+wiring+(basics+OR+101)
  
• http://web.archive.org/web/20080213151445/http://www.kevinboone.com/domesticinstallations.html
  
• [wiki]Electrics%3ALighting[/wiki]
  
• [wiki]Electrics%3Abooks[/wiki]
  
• [wiki]Electrics%3Aindex[/wiki]
  
  

 

[Rredwin]

I appreciate that, which is why I have had the dimmer switch for a week now and haven't attempted anything until I'm 100% certain I know what's going on.

I'm not fiddling, I just want to replace it; if that's too big a job for me I won't do it.

 

[Rredwin]

Thanks again for all responses so far in this.

Can someone confirm that I need to earth the faceplate rather than the backbox as it currently is?