Feeding new wires down a Stud Wall

[Chicken]

Does anyone have any tips on how to feed two lots of2mm twin + Earth cables down inside a stud wall.

I want to wires to go from a junction box in my loft to a 2 way swith on the stud wall WITHOUT making a channel, the wall has only just been plastered and the missus has decided she wants the lights to operate on different switches!!

Is it safe to power a second set of lights by using the live wire feeding the existing switch? as this would make life a lot easier.

Thanks

 

[plugwash]

firstly there is no such thing as 2mm T&E

lighting cuircuits are generally done 1mm or 1.5mm sometime 2.5mm is used in commercial setups but it's very unusual in a house

it's fine to use the existing live wire but unless you have conduit in place you aren't allowed to use singles anyway so it doesn't help much

here is probablly the easiest soloution

use the existing cable to pull down a 3 and earth and terminate it in a 6 terminal junction box (1 terminal unused)

so in the jucntion box you have the cuircuit live neutral and earth and 2 switched lives to run your lights off

 

[dingbat]

Hi chicken. Is this post about two different jobs? Just wondering where you get 2mm cable from and why you'd be using this for lighting? A bit more detail about exactly what you want to do might help.

The best way to convert to two-way switching is to run three-core-and-earth from the existing switch to your new switch position - no need for a junction box. Use a stud finder to locate the horizontal noggins in your wall and try to position your new switch above the highest (unless this is too high for practicality) cut out a hole in the plasterboard to take a drywall back box then drill through from the loft into the cavity. You should be able to drop your wires down and fish them out of the switch hole.

Before you do any of this though, have a look at the post entitled 'for reference' at the top of the Electrics UK forum index.

And although it is possible to use the live feed to a switch, from where will you get your neutral? It's not a good idea to mix wiring formats on the same circuit - that is, having some lights wired as loop-in and others wired in singles. It can get confusing.

 

[Chicken]

Thanks Dingbat & Plugwash, my mistake, I meant 2.5mm T+E because (and this is where it gets really complicated) -

The first set of lights is in my bathroom, wired in and running fine, the missus wants some floor spotlights that are low voltage and suitable for the job.
The transformer on the spotlights is for a 13amp socket. So i was going to wire a socket to the existing bathroom lights (i've checked, it wont overload it) and then have the socket under the floor boards so nothing else can be plugged into it with stickers displaying MAX LOAD 6AMPS

Originally, the spotlights were going to be connected to the switched live in the junction box but now she wants them switched independantly.

I didn't really want to rip out the existing wiring! it was bad enough getting THAT in the wall

Cheers

 

[Chicken]

it's fine to use the existing live wire but unless you have conduit in place you aren't allowed to use singles anyway so it doesn't help much

When i said about using the live wire, i meant using it connecting it to 'com' on both sides of a two way switch then connecting neutrals together and both earths to the metal casing in the wall

 

[plugwash]

ahh wired via switch box rather than looped in like

earths ommitted for ease of diagramming all cables are assumed to contin erths which should be connected together and to any earth terminals at every fitting

[code:1]

--------switch-------
supply light
------chock block----


[/code:1]

nothing wrong with this (it's just unusual) and yes you can extend it like this


[code:1]
.----------switch----------
------'-switch-------- |
supply light light
------chock block------ |
'---------------------'
[/code:1]

 

[Big_Spark]

Thanks Dingbat & Plugwash, my mistake, I meant 2.5mm T+E because (and this is where it gets really complicated) -

The first set of lights is in my bathroom, wired in and running fine, the missus wants some floor spotlights that are low voltage and suitable for the job.
The transformer on the spotlights is for a 13amp socket. So i was going to wire a socket to the existing bathroom lights (i've checked, it wont overload it) and then have the socket under the floor boards so nothing else can be plugged into it with stickers displaying MAX LOAD 6AMPS

Originally, the spotlights were going to be connected to the switched live in the junction box but now she wants them switched independantly.

I didn't really want to rip out the existing wiring! it was bad enough getting THAT in the wall

Cheers

Now that is why I object to DIY. No-one has even picked up on what has been said here. YOU CANNOT CONNECT 13A SOCKET-OUTLETS TO A LIGHTING CIRCUIT...EVER.

 

[plugwash]

people keep saying this but noone has pointed to a reg that demands it!

 

[Big_Spark]

people keep saying this but noone has pointed to a reg that demands it!

Do you need a regulation to tell you not to stick your hand in a bonfire?

It's the same thing. Connecting 13A sockets to any circuit that is not designed for them is potentially dangerous. He is planning to put one in a ceiling void ABOVE a BATHROOM, and another under the floor of a BATHROOM.

Now forgive me for seeming picky here, but as they are in the bathroom, whether behind a piece of plasterboard or wood is irrelevent, then they are BANNED to all intents and purposes.

However common sense must also play a part here. What is wrong with wiring the lights into the lighting circuit normally, it is compliant and safe.

Chicken, what sort of lights do you intend to install in the floor? They will need to be waterproof, not simply splashproof.

 

[dingbat]

The first set of lights is in my bathroom, wired in and running fine, the missus wants some floor spotlights that are low voltage and suitable for the job.
The transformer on the spotlights is for a 13amp socket. So i was going to wire a socket to the existing bathroom lights (i've checked, it wont overload it) and then have the socket under the floor boards so nothing else can be plugged into it with stickers displaying MAX LOAD 6AMPS

Yeesh! You didn't explain that in your original post. Please amend my original response to read - "Call an electrician and don't touch another electrical thing!"

 

[Chicken]

He is planning to put one in a ceiling void ABOVE a BATHROOM, and another under the floor of a BATHROOM.

I may be not all that hot on wiring, but i do know that water and electricity dont mix.

There is amout 15m of cable on these light so the socket is under the floorboards well away from the bathroom, as are the JB's in the loft.

The lights are completely sealed units and only these lights are to be plugged into the socket - nothing else. They pull less than 2 amps.

OK - heres another way around, If i wire the socket into the RING MAIN, can I use one side of the 2 way light switch to operate it or isn't the light switch up to it (Personally, I dont think it is)

 

[Big_Spark]

Chicken, NO, sorry to be a damp blacket about this.

Why don't you simply take the ceiling lights from the normal lighting circuit via the switch and a JB, if it is required, and then the underfloor lights can be supplied via the ring, howver they should be connected via a fused spur (most here call them Fused connection units). It will not need a switch, perhaps just aneon on the output side so you know if the fuse blows. This could be mounted at low level, outside the bathroom, and then the supply can be fed through a light switch to the transformer for the lights. This switch would need to be independant of the lighting circuit switch to maintain isolation of circuits.

 

[Chicken]

OK, confused, I still need to plug the transormer into a 3 pin socket, its one of these block transforer jobs, so your saying that I can wire the socket to a Ring main, and use a light switch to operate it, correct???

Maybe I got the terminology wrong, the switch plate I want to use has two switches on it, can one switch be used with the lighting circuit to operate my existing ceiling lights, and the other switch operate a spur of a ring main to power the transformer / floor lights?

 

[Big_Spark]

Why have you got a plug in Tx for these lights? They are for permanent installtion and should not be plugged in!!

 

[Chicken]

The transformer came with the lights from micromark, they are LED lights, very low voltage, suitable for exterior decking, you can plug up to 18 of these lights on one tranformer, I'm only using 6 here are the details