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Topic Title: These new fangled ideas!
Topic Summary: 1.5mm lighting cable & feeds to switches
Created On: 09 February 2013 06:50 AM
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 09 February 2013 06:50 AM
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normcall

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I spent most of yesterday in wonderment going round a less that 10 year 'luxury' home wired by a NICEIC contractor.

I all started with the usual recommendation to sort problems out. Nuffin like 6 dimmers on a 6g plate, 1.5mm cables complete with feeds/neutrals, up to 400w of 12v recessed lights per dimmer and the plate got hot.

What a mess? I installed an 18G plate with a bit more space, but just 4 dimmers and a couple of switches - at least it was a lot better!

Done by lunch time, but then the 'while you are here.........' statement I really do dread. ' We don't know why these lights don't work', followed by ' the landing lights only work if this switch is on'. You get the picture!

I took one switch off only find a lot of the wires didn't come with the switch. Not really surprising as I expected the 3 * 1.5mm cores would have made it difficult anyway. One of the switches had given up the ghost of having the terminals bent of of shape and compressed so much.
The customer was not amused and we have agreed to come back in the warmer summer weather to attempt and resolve this difficulty.
It wouldn't be so bad if it wasn't done by a local NICEIC contractor. What was the inspector thinking off? Money and not much else like standards!

So my question is to all you new boys (apart from why the hell do you do it?), apart from installing a lot of deep boxes and connectors, do you have an easier solution?

-------------------------
Norman
 09 February 2013 08:56 AM
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broadgage

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With the general use of 1.5mm cables for lighting, more complex lighting circuits with multi gang switches, and the looping of neutrals at light switchs, I feel that the use of shallow boxes for light switchs should be discouraged and possibly prohibited by regulation.

For example "shallow boxes XXmm or less in depth are not to be used when more than 4 conductors are present in the box. If the circuit design requires more than 4 conductors then a box at least YYmm deep is to be used."
 09 February 2013 09:07 AM
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stateit

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Originally posted by: broadgage


For example "shallow boxes XXmm or less in depth are not to be used when more than 4 conductors are present in the box. If the circuit design requires more than 4 conductors then a box at least YYmm deep is to be used."


That's more of a Regulation of Good Judgement ...(as is a fair chunk of BS7671 now) as opposed to Regulations due to physics (thermal capacity of cable etc...)

My take is if the box is not going to have enough working space inside, then make it deeper. If the one block thick wall won't take a deeper box, then make the box a double....

-------------------------
S George
http://www.sg-electrical.com
 09 February 2013 11:25 AM
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SKElectrical

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Originally posted by: normcall
agreed to come back in the warmer summer weather to attempt and resolve this difficulty.


excuse me?!!!
 09 February 2013 11:52 AM
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normcall

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The guy had lived with the problem for some years, it's not urgent and he'll have to save up some money.
I stopped being a charity some years ago!

-------------------------
Norman
 09 February 2013 12:11 PM
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dbullard

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Originally posted by: normcall

The guy had lived with the problem for some years, it's not urgent and he'll have to save up some money.

I stopped being a charity some years ago!


Like you Norman, I no longer have charity status, this was relinquished some years ago by the charity commission (wife and dependents), and it still amazes me to this day that some call outs still ask for the charity badge to be shown upon entry ............

None of us can afford to run around for nowt, I have mates rates as everyone or if I know some one is really struggling I will offer to help for a favor returned.


Regards

Daren

-------------------------
..... Dont pee in my pocket and tell me its raining ......


www.quest-electrical-sw.co.uk
 09 February 2013 08:10 PM
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impvan

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You can get 10mm surface spacers for faceplates, the ones I've used were made by BG.
 09 February 2013 09:25 PM
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MrOther

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Norm I must be honest I've done something similar in one of my first PJs at home. Not as bad as you described.

I don't understand people who overload their back boxes consistently - it just makes installations hard let alone testing and future fault finding.

I almost came a cropper recently.

Installed some Click 5A round pin plug with a 13a 1G socket. Double metal patress/front plate, but the sockets were plastic and clicked into the patress like mini grid system.

Anyway, the sockets were easy, loop-in and -out.

The first 5a though was a plain, (remember you have the socket loop in and loop out) I now had to contend with the SL, loop out and strappers. The problem being the multiple cpcs: each cable, plus a fly lead to the back box, the patress, each socket. Got kind of complicated.

So just banked most of them in a wago non-maintainable terminal block. Left a little slack for the person coming after me, seemed to do the trick and I was quite happy. The tick of course, when the person comes after me feels the same way. Hopefully so.
 09 February 2013 09:27 PM
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MrOther

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Originally posted by: broadgage


For example "shallow boxes XXmm or less in depth are not to be used when more than 4 conductors are present in the box. If the circuit design requires more than 4 conductors then a box at least YYmm deep is to be used."


I woul just ban 16mm outright nowadays, most modern fittings don't seem to fit in them, swap a dimmer only yesterday to find it had to much "ass" on it to fit into 25mm.
 09 February 2013 09:55 PM
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sparkingchip

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Deep boxes and wago type connectors are the order of the day with neutrals in the switch box. I regularly install 47mm deep galvanised knock out boxes for light switches if I think a dimmer will be installed, otherwise 35mm or 25mm, never a plaster depth box.

Andy
 09 February 2013 09:58 PM
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Martynduerden

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Originally posted by: broadgage

For example "shallow boxes XXmm or less in depth are not to be used when more than 4 conductors are present in the box. If the circuit design requires more than 4 conductors then a box at least YYmm deep is to be used."


Given that we can do absolutely everything necessary over a single cat5 I struggle to see why we still install mains wiring to any switch...

I use 35mm minimum for almost everything.

-------------------------
Regards

Martyn.

Only a mediocre person is always at their best



www.electrical contractors uk.com
 10 February 2013 08:57 AM
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AJJewsbury

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I use 35mm minimum for almost everything.

me too.
- Andy.
 10 February 2013 11:25 AM
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ebee

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Personally I have never used 16mm ("PD") depth boxes for years.
25mm minimum to me for anything.
35mm if you need a bit more room - that`s the depth I usually start seriously thinking about how much substance is on the brick/stonework behind it.

If I see an existing PD box on a 1G 1W switch then I don`t bother too much unless someone wants a dimmer on it but anything else makes me cringe.

-------------------------
Regards,
Ebee (M I S P N)

Knotted cables cause Lumpy Lektrik
 10 February 2013 12:10 PM
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stateit

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A customer of mine has specced 47mm deep metal / 45mm dry lining boxes for his build - A joy to work in.

Thanks Tim if you're reading this!

Fortunately the majority are dry-lining boxes, so not too much deep digging into walls!

-------------------------
S George
http://www.sg-electrical.com
 10 February 2013 12:44 PM
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daveparry1

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I find 25mm just about does a ring socket ok but 35mm needed if there's a spur supply present, for light switches 25mm is usualy ok unless there's a deep dimmer there, (800watt etc) I find fcu's are more of a problem!

Dave.
 10 February 2013 02:03 PM
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sparkingchip

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I don't have a lump hammer on the van at present, it's the electric drill with chisel in it for chopping out.

Andy
 10 February 2013 02:27 PM
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daveparry1

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Can't beat a Scutch chisel and club hammer I say!
 10 February 2013 04:41 PM
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ebee

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Or better still SDS on roto stop with a combed scutch bit

-------------------------
Regards,
Ebee (M I S P N)

Knotted cables cause Lumpy Lektrik
 10 February 2013 04:45 PM
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Martynduerden

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Originally posted by: ebee

Or better still SDS on roto stop with a combed scutch bit


I can never get the combed bit to stay in, i usually cut the box with the chaser and break out with the cordless hilti on rotostop - fairly quick and painless.

-------------------------
Regards

Martyn.

Only a mediocre person is always at their best



www.electrical contractors uk.com
 10 February 2013 04:56 PM
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daveparry1

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Using the chaser in an empty house is ok Martyn, I often use the 4 inch angle grinder and make 4 cuts then chisel out the centre , but in an occupied house (which most of my work is) it just creates too much dust,

Dave.
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