Running an extra neutral core to a light switch

[sambartle]

When I bought my house I had it completely rewired by an Electrician, and whilst doing that he re-wired all the lights.

They are wired in standard UK 2-wire format, with T&E from the ceiling rose to the switches, so in the switch I only have live, earth and switched live.

The wires for the one switch in question are chased into a plasterboard wall, and they have plastic capping over them before being plastered in.

My question (and its purely theoretical at this stage), is do you think it'd be possible to manage to poke down from the loft a single core to add neutral at the switch? it's only got to go about 1m straight down the back of the capping.. but is it possible?

I'm thinking an electrician could perhaps use one of these cables..
Either Single Core Conduit: http://www.screwfix.com/p/conduit-wiring-cable-6491b-lsf-1-5mm-x-100m-blue/92520

Single Core Double Insulated: http://www.ebay.co.uk/itm/6181y-Sin...5631dda&pid=100005&rk=2&rkt=6&sd=111444103430

But what is the chances of being able to manage to shove it down beside an existing cable behind the capping? (I doubt cable rods will fit as they will be wider than this cable i suspect)

I ask as I would like to buy a wifi controlled light switch for this room, and the ones I would like require a neutral connection so they can be powered all the time without needing to leak current to power themselves via a 2-wire live only connection.

I dont want to risk trying to pull up the existing cable to feed up a three core cable.. (im not sure if its clipped behind the capping but i suspect so..), and dont want to re-channel and plaster the wall..

Would it even be allowable to do that as it wont be clipped down the length (but could be at the top and bottom of the capping so about 1M unclipped max in the middle..

Thoughts?

 

[PrenticeBoyofDerry]

Thoughts?

A chance but very unlikely without causing damage to the cable or and wall.
Is the wall render plastered or boarded?

 

[Taylortwocities]

Why do you need a neutral at the switch?

 

[sambartle]

Thanks for the quick reply..

The wall is rendered.. (I just had a quick check - as i incorrectly said it was boarded before.. its not in this room.)

 

[sambartle]

Why do you need a neutral at the switch?

I'd like to buy a wifi controlled light switch for this room, and the ones I would like require a neutral connection so they can be powered all the time without needing to leak current to power themselves via a 2-wire live only connection.

It's tricky to find a 2-wire live only version that doesnt look like a chinese fire hazard- Plus I suspect my LED lighting wouldnt appreciate the tiny current that leaks through those live only ones.. like it doesnt like dimmers.

 

[Jackrae]

I'm eagerly awaiting someone to suggest using the earth wire

 

[ban-all-sheds]

Hopefully a long wait.

 

[ban-all-sheds]

I'm thinking an electrician could perhaps use one of these cables..
Either Single Core Conduit: http://www.screwfix.com/p/conduit-wiring-cable-6491b-lsf-1-5mm-x-100m-blue/92520

No.

Single Core Double Insulated: http://www.ebay.co.uk/itm/6181y-Single-Core-1-5mm-Double-Insulated-Blue-neutral-wiring-cable-lights-5m/111444085627?_trksid=p2047675.c100005.m1851&_trkparms=aid=222007&algo=SIC.MBE&ao=1&asc=36381&meid=51e5b5cb04974cf797ce245625631dda&pid=100005&rk=2&rkt=6&sd=111444103430

That's the type it would have to be.

I ask as I would like to buy a wifi controlled light switch for this room

Writing it "Why fi?" might help clarify your thinking.

 

[sambartle]

No.

Thanks

That's the type it would have to be.

I assumed so, but wasn't sure as shoving the single core stuff down the back of some plastic isn't that different from shoving it down some plastic conduit..

Writing it "Why fi?" might help clarify your thinking.

Why? So I can control it via a home automation device. Or my phone. Or just because I can.. any of the above.
That's like asking why do you bother having light switches at all.. you could just turn off the consumer unit when you want the lights out. Its about convenience.

Cheers all.

 

[bernardgreen]

Or my phone ~~~~~~~ Its about convenience.

You can't find your mobile phone.

You need to turn the light on to find the phone.

You need your phone to turn the light on.

You need to turn the light on to find the phone.

and so on and so on........

 

[sambartle]

They work like normal switches as well as being wifi controllable.. so i could press the wall switch.. like i do now.

I dont need to know where my phone is though.. as I can control everything via my watch.. Id add support for the switch to the app i built for that.

 

[Risteard]

I assumed so, but wasn't sure as shoving the single core stuff down the back of some plastic isn't that different from shoving it down some plastic conduit..

It is very different to having it in free air outside the conduit, however.

Incidentally, there is no such thing as "double insulated" cable in your link. It is insulated and sheathed. The sheath is for mechanical protection and its insulating properties are untested.

 

[bernardgreen]

Sam

It is necessary sometimes to do a reality check when modern technology is tempting one to automate their house.

Four friends dabbled with a lot of home automation and then removed it completely or reduced the amount of automation to a level that friends and visitors could cope with. A colleague and her partner built a house that was brimming with automation and then a change of employer meant they had to sell it to relocate. The high level of automation put buyers off and I believe they had to "de-automate" before they sold it.

I have on more than a few occasions been involved where home automation components / systems have failed and replacements are no longer avialable.

 

[sambartle]

It is very different to having it in free air outside the conduit, however.

I thought conduit usually had holes in the bottom bends to allow moisture/vapor to drain out? In which case surely the air is just about as free as when sandwiched between brick and plastic capping? Unless cable conduits are sealed.. which seems unlikely as you'd get condensation in there..

(dont worry i wont be using that stuff anyway as i know its not correct - mind you im not proposing doing it myself anyway.. but i now know that it would need to get the slightly thicker stuff down.)

Incidentally, there is no such thing as "double insulated" cable in your link. It is insulated and sheathed. The sheath is for mechanical protection and its insulating properties are untested.

Yes, I did know that, but I used the wording the ebay listing does.. apologies

 

[sambartle]

Sam

It is necessary sometimes to do a reality check when modern technology is tempting one to automate their house.

Four friends dabbled with a lot of home automation and then removed it completely or reduced the amount of automation to a level that friends and visitors could cope with. A colleague and her partner built a house that was brimming with automation and then a change of employer meant they had to sell it to relocate. The high level of automation put buyers off and I believe they had to "de-automate" before they sold it.

I have on more than a few occasions been involved where home automation components / systems have failed and replacements are no longer avialable.

Understood.. im only proposing to do one light switch.. in a room that already has other control systems fitted.. which can be easily removed if i do move..

I think prospective buyers would be more off put by the massive hole in the ceiling I'd have to re-plaster where the projection system is mounted

Or the arcade machine that's too big to leave the property since i re-built the staircase AFTER getting it upstairs.