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Old Mar 20, 2002 | 09:59 AM
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OK, just in the middle of re-decorating the kitchen, and have decided whilst the paper is off to integrate 3 picture lights into the back wall.

I have done a few images to illustrate. This is the current situation with the wall:



So far we have a single switch near the back door for the outdoor security light. I have chased out the plaster up to the position where the lights will be.

And here is the desired outcome (ignore the picture, they are just to illustrate the fact that pictures will be there):



Now, the bit I need help with is this. I am thinking of changing the single switch for a double switch, then using a spur cable of the mains in supply to power the second switch. The lights will then be connected in serial (I think). Like this:



So I need to know if this is the correct wiring configuration.

Also, is there anything else I need to know about routing the wires, re-plastering etc.

I am planning on skimming over the wall after, and leaving enough wire coming out at each light point.

Any help would be appreciated.

DW
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Old Mar 20, 2002 | 10:50 AM
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I'm no expert, but I believe that wiring regulations require that the cables to and from the lights/switches run vertically up and down the wall, and may only run horizontally above the ceiling or under the floorboards. This is so that when people knock nails into the wall, they know (in theory) that it's safe as long as they're not directly above or below an electrical fitting.

Of course, anyone with half a brain would use a live wire or metal detector before bashing nails in, but they're not 100% reliable.

As for joining the lights in series as you've shown, I don't see any problem with that. I'm sure some of my lights (in a newly built house) are connected that way.

Of course, they're not really in series like a string of fairy lights, or they'd be awfully dim and one dead bulb would stop any of them working, but your diagram shows that).

If in doubt, consult a qualified electrician... blah... blah...

A.
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Old Mar 20, 2002 | 11:02 AM
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You could ask the question on the uk.d-i-y newsgroup. They have a web site too DIY FAQ, but I couldn't see any diagrams explaining the wiring.

The regs used to be published free online, but I think you need to subscribe to get them now. Have a look at http://www.iee.org for more info.

Stefan
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Old Mar 20, 2002 | 11:05 AM
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as above - you need to run the cables vertically. I'm assuming that you won't be involving building control etc, so you could get away with it as the diagram, but it could be dangerous.

The wiring configuration looks ok, but sometimes the switched lead is a neutral from the light, (it will probably still have a red sheath though, just to add confusion,) but if this is the case, either your outside light will come on every time you switch on the picture lights, or you picture lights will only come on if the outside light is on, depending on where you run the picture light neutral to.

Safest bet would be to take the live feed from a ceiling light, feed this to a junction box in the ceiling and run the switch from the junction box. This would be straight forward if I could diagram like you could
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Old Mar 20, 2002 | 11:07 AM
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Don't forget your metal sheathing over the wires before you bury them too
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Old Mar 20, 2002 | 11:07 AM
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p.s. - When you are replastering, use a mixture of bonding and finish. If you use finish only it will sag as it dries. Leave it slightly proud and rub over it with a wet trowel half an hour after you put it on. Sand it to a smooth finish after it dries completely (2-3 days)
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Old Mar 20, 2002 | 11:16 AM
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As mentioned . You must run your cables vertical and horizontally, Make sure you cover the cable with plastic conduit or metal guard strips.
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Old Mar 20, 2002 | 11:27 AM
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A neutral wire coloured red?! I doubt that, unless you know better.

Normally the colours used in buried cables are red for live, and black for neutral. Earth is green with a yellow stripe, like in a flex.

A.
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Old Mar 20, 2002 | 11:32 AM
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Switched lives are marked with red tape (IIRC)
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Old Mar 20, 2002 | 11:38 AM
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Bolloxing bollox - so I need to chase the wall out vertically first - sickener [img]images/smilies/mad.gif[/img]

Better get the plaster out tonight and start again.

So would this be better:

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Old Mar 20, 2002 | 01:15 PM
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The circuit is correct, just make sure you switch the live not the neutral otherwise 240V will always be present at the light fittings!
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Old Mar 20, 2002 | 01:27 PM
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DW - Vertical is up and down, so you need to track from ceiling down to the fitting for each one.

Andy - The neutral can be carrying current some or all of the time depending on the circut. If it is taking a feed from the light fitting after the bulb to the switch it is technically a neutral, but one side will always be live, so a (competent) spark will replace the black sheath with a red one to show this is the case
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Old Mar 20, 2002 | 01:30 PM
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FB

Cheers - however, that is not possible. The ceiling has a coving on it which cannot be moved, and we cant get to the ceiling void from above. Is it *defo* not advisable to do a bit of horizontal?

DW
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Old Mar 20, 2002 | 01:36 PM
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You could use the track you have already cut, but will you remember exactly where it is in 5 years? It wouldn't pass building control, but if you can't gets into the ceiling then horizontal or diagonal wont make much difference. Have you access to the floorspace?
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Old Mar 20, 2002 | 01:44 PM
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We wont be living here in 5 years time

I think I will re-check the ceiling void again, though I needed this to be a small job as the rest of the kitchen project is massive.

Looks like it is getting complicated.

The floor is concrete so no go there either. How about running them down to the skirting board, then behind?

DW
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Old Mar 20, 2002 | 01:51 PM
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your easiest and safest option might be to use metal conduit and armoured cable. The main problem is that if someone sticks a nail through it at any time in the future they will most probably die. An electrician might be your best bet, as they will route the cable correctly and generally do this as if by magic.
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Old Mar 20, 2002 | 01:55 PM
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Well I dont want to kill anyone, so time for Plan B.

FB are you a spark? If so, how much roughly would it be for something like this?

Cheers for the help.

DW
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Old Mar 20, 2002 | 02:05 PM
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Chances are there wont be a neutral into the switch...it all depends on how the electrician initially wired the outside switch.

I would have thought he would have a switched neutral return (is there a black wire in the switch with red tape/sleeze on it) ?

How many wires into the switch ?

When you do the picture lights, I always like to use metal backing boxes as opposed to the wire just appearing out the wall.

J.
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Old Mar 20, 2002 | 04:45 PM
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Old Mar 20, 2002 | 05:01 PM
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DW - not a spark, but spent many summers weilding a grinder for one when I was a student. Call a couple of locals and explain it to them. See if they will give you a ballpark figure. It usually depends how much work they have on!!
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Old Mar 20, 2002 | 05:14 PM
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Cheers Rik

firefox - the switch has 3 wires going in. A red wire to the top of the switch, a red wire to the bottom of the switch and a black wire which earths to the casing. It also seems to have 2 copper wire alongside the bottom red wire which also earth to the case.

DW
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Old Mar 20, 2002 | 05:43 PM
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There are 2 ways to wire up a lighting circuit so it depends if you're lucky or not

1) Live, Neutral & Earth wired in a ring round the house to the celing rose. From there a single piece of twin flat & earth cable runs to the switch. This will only run the LIVE cable and there will be red tape or a red sheath around the negative (black) cable. This is the most common method and means that you have no neutral at the switch.

2) Live, Neutral & Earth wired in a ring round the house to the switches and a single piece of twin flat & earth cable runs to the light. Less common, more cable in the backbox (3 sets - 2 for ring & 1 to the light) but that would let you do what you want to.

Should be OK wiring to an outside light but depends on the wattage - you may overload your lighting circuit.

Find the fuse/breaker for the lights and if you have more than 1 then switch one off and work out which lights are on which circuit.

The formula is I=P/V where I is current in Amps - so your fuse rating, P is power in watts so the total of your light bulbs and V is voltage so 240.

The other advive is good - metal capping not plastic and don't run cable diagonally. Ideally it should just be vertical but horizontal should be OK for wall lights.

I'm not a spark, so not familiar with current regs, but I do have a degree in this stuff........
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Old Mar 20, 2002 | 06:21 PM
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I'm a spark and would look for around £50 notes dependent on where I could get a neutral from.

Cheers, Crypt.
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Old Mar 20, 2002 | 06:52 PM
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Dream...

I'm a little concerned about the "black" wire going to the case as an earth.. its slightly the wrong colour!

The two red wires I can understand. If the black wire is indeed the earth, then you will have problems sourcing a neutral and the difficultly of doing the job doubles.

Unless those two extra wires at the back/bottom join together, tehn they could be the neutral that someone has fed in and looped out.

So basically you have two lots of 1.0mm FT&E going to the switch ? One red is power in, one red is switch power out to the light, the black wires are going together, and the earths are sleeved (maybe in black sleveing - which is wrong) but go to the case.

If so, then your original idea will work.

Fit a double gang switch, wire one side like the current switch, Red to the common, other Red to the switched terminal. Then bridge from one common to the other common.

Connect your Red wire from your new lights to the terminal for the second switch, and the black wire from your new lights to the looped/joined black wires. Dont forget to common all the earths too.

This will then work.

Chances are your double gang switch will be two way, so each gang will have one common, but two switched terminals. You only need to use one of the switched terminals on each gang.

J.

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Old Mar 21, 2002 | 08:29 AM
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Crypt - you fancy doing it for £50 ish? Where in the NW are you? Also need a plug outlet putting in as well in the same wall.

I can do all the crap chasing out, fitting casings etc if neccesary.

DW
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Old Mar 21, 2002 | 10:53 AM
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Crypt

Hope your price doesnt include chasing and making good.....£50.00 It NOT enough. This would be worth £200 in London
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Old Mar 21, 2002 | 11:07 AM
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Luke - we only earn enough oop't North to keep us in Whippets and Flat caps, so things are cheaper up here

DW
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Old Mar 22, 2002 | 09:24 AM
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Luke - we are building an extension and I just got a price for 2 lights, six double sockets, 1 ceiling extractor fan and 1 smoke alarm for 280 quid including material. (Obviously making good doesn't apply) You are all being had in Londaon
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Old Mar 22, 2002 | 03:49 PM
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£870.00 council tax............
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Old Mar 22, 2002 | 04:08 PM
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ouch
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