Want to fit a dimmer switch but new build strange wiring!!

[djmarkymark]

Hi,

I've been a reader of the forum for a few weeks and found it very helpfull. But it's come the time for me to post a question!

I have just moved into a new build and I have a light switch I wish to change to a dimmer switch. One switch controls the downlights, one switch controlls the uplights.

I opened up the switch and saw that they have wired all the neutrals together and seem to just have the live's into the current switch.... so, I can't work out what should be in my new dimmer in the two sets of L1, L2 and C (I think).

Here is the current wiring set up.

Anyone know how to connect the new one?

Thanks.[/img]

 

[DJDUNKY]

Why is there a wire not connected to anything!!?

Basically your new 2 gang dimmer needs to be wired as per the light switch.

Leave the Neutrals together in a terminal block, tape around too.

The the power (C) that you have linked together will need to be the same in the dimmer.

Your 2 switched lives, need to be moved to each dimmer (1) or (L1).

The brown switched wires really should be tagged as switched!!!

 

[IJWS15]

At a guess I'd say the loose brown wire is the other switched live and has broken when you took the switch off. There may be a piece of copper in one of the two lower left hand terminals on the switch.

Do all the lights still work?

Treat it cautiously until you know whether it is live or not - do you have a multimeter?

 

[djmarkymark]

Yeah, I don't know what the brown wire that isn't connected is for.... do I need to connect it to anything?

So... do I connect the two wires that are in L to the two "C's" in the dimmer then the wire that is in 1 to the "L1" in my dimmer?

 

[djmarkymark]

At a guess I'd say the loose brown wire is the other switched live and has broken when you took the switch off. There may be a piece of copper in one of the two lower left hand terminals on the switch.

Do all the lights still work?

Treat it cautiously until you know whether it is live or not - do you have a multimeter?

When I moved it there were two sets of wires hanging out of the wall at 4 points around the living room (well, only one set at the end). Obviously for wall lights.

Now I can't remember properly, but when it came to the switch I think the connecting brown wire at the top was not connected (so not to send elec to the wires out of the wall around the living room). So, I'm guessing I connected it and so there was power to the first set of wires out of the wall (for the wall lights).

I connected all the lights up on the wall and everything works fine.

I have a multimeter yes. newly acquired to try and sort this out.

 

[Lectrician]

Why is there a wire not connected to anything!!?

Basically your new 2 gang dimmer needs to be wired as per the light switch.

Leave the Neutrals together in a terminal block, tape around too.

The the power (C) that you have linked together will need to be the same in the dimmer.

Your 2 switched lives, need to be moved to each dimmer (1) or (L1).

The brown switched wires really should be tagged as switched!!!

NO - thats an awful habbit - a true DIY way.

Would you tape up the back of the switch terminals aswell?

I don't like seeing the earths in a sleeve with no terminal block on the end - expecially as this appears to be loop in loop out at switches.

Do both switches currently operate something? The second gang has no cable, which suggests not, but as others have said, this could be the cable thats loose.

Really? How do you propose to do that - brown sleeve over the brown core? LOL - switched or not, it's a brown core, it's fine.

 

[djmarkymark]

Why is there a wire not connected to anything!!?

Basically your new 2 gang dimmer needs to be wired as per the light switch.

Leave the Neutrals together in a terminal block, tape around too.

The the power (C) that you have linked together will need to be the same in the dimmer.

Your 2 switched lives, need to be moved to each dimmer (1) or (L1).

The brown switched wires really should be tagged as switched!!!

NO - thats an awful habbit - a true DIY way.

Would you tape up the back of the switch terminals aswell?

I don't like seeing the earths in a sleeve with no terminal block on the end - expecially as this appears to be loop in loop out at switches.

Do both switches currently operate something? The second gang has no cable, which suggests not, but as others have said, this could be the cable thats loose.

Really? How do you propose to do that - brown sleeve over the brown core? LOL - switched or not, it's a brown core, it's fine.

Hiya. What do you suggest I do to fit the dimmer? Shouldn't the earth be connnected to anything?

 

[davy_owen_88]

You have a plastic front plate and a plastic drylining box, there is nothing that requires earthing so the cables should be sleeved (as they are) and the end terminated in a terminal block to ensure continuity throughout the whole lighting circuit.

 

[djmarkymark]

You have a plastic front plate and a plastic drylining box, there is nothing that requires earthing so the cables should be sleeved (as they are) and the end terminated in a terminal block to ensure continuity throughout the whole lighting circuit.

Metal wall lights though... does that matter?

 

[davy_owen_88]

You need to make sure there is CPC continuity throughout the lighting circuit. Since the earths pass through the light switch in question, and the earth connection between the 2 cables is relying on the compression of the G&Y sleeve itself, you really need to fit a terminal block.

 

[djmarkymark]

Ok great.

Although, I still don't know the answer to my orig question.

Which wires do I put in L1, L2, C and L1, L2, C (2 switches)?

Thanks

 

[ColJack]

Yeah, I don't know what the brown wire that isn't connected is for.... do I need to connect it to anything?

So... do I connect the two wires that are in L to the two "C's" in the dimmer then the wire that is in 1 to the "L1" in my dimmer?

yes...

those terminals on the second switch are not tightened down.. ( see how the screw in the terminal that is tightened is suken ...? )

the second switch currently switches nothing without a cable in the 1 terminal..

I'd trace that other cable and see what it goes to... might be an outside light feed or something..


on a side note, that plastering is f'ing attrocious.. they plastered round the light switch too by the looks...

 

[djmarkymark]

on a side note, that plastering is f'ing attrocious.. they plastered round the light switch too by the looks...

Ha... no, that is silicone that they have used to seal it. It's just come away when I've taken the switch off. Will be fine when I get the new one on.

 

[djmarkymark]

the second switch currently switches nothing without a cable in the 1 terminal..

Ahhhhhhhh.... do you know what... I think I took this picture before I stripped the hanging brown cable and attached it to the empty "1" terminal!!!!

Sorry, I'm new to all this wiring business.

That is what I must have done. So.... I guess I have to connect the two browns at the top to my new "C's" then the two at the bottom to L1 and L1??

Do I still need to join the two at the top together? (joining the to "C's" together?)

Sorry for the confusion.....

 

[Steve]

Ha... no, that is silicone that they have used to seal it.

Yuck! Why????

Does that wire say "leave in back"? Do you know what it does?

Did you say this is a newbuild? And you had to connect the lights and switches yourself?