Slimy38
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| posted on 2/9/12 at 12:36 PM |
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Any house electricians? Need advice.
My brother in law is in a fairly old house, and is needing to put some lights into his loft. The current lights for the entire house is fed off one
twin and earth (fairly beefy from memory) from one RCD to a really old looking junction box. From here, there's various connectors inside it
that feed power and switch to each of the lights.
What he's done to provide the lights in the loft is take a 2.5mm T&E feed from the main block (connected directly to the original T&E
from the mains), feed that to another junction box then do the same thing to feed the remaining lights.
So there's basically one spur, with two star/fan (not sure of the correct term) fed off it.
I'm sure it's not the best way to do it, but would it pass the relevant tests to get the certification?
[Edited on 2/9/12 by Slimy38]
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cliftyhanger
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| posted on 2/9/12 at 12:41 PM |
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Not a leccy, but first thing is it will deffo need to be fused down, really to 3 or 5 amps. That is what was done 20m years ago on my loft
conversion.
Otherwise there should be no real issues, unless the regs have outlawed fused spurs now?
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Strontium Dog
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| posted on 2/9/12 at 01:25 PM |
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Sorry Mate but that's a NO. All of it is wrong! None of it is right! You need a competent electrician or it'll all end in tears (not to
mention smoke and flames). NO spurs of any kind let alone "star" configurations are allowed. Lighting is a radial circuit with no
exceptions and each run is restricted in length according to cable size and protection value (fuse/trip size). I could go on but to be honest if you
don't know about the above then the best idea is to not touch.
Without even looking from what you have said it needs a rewire to pass a 17th edition test. Sorry but that is about the size of it I'm afraid.
And yes I am qualified! 
U2U me and I'll give you my no. and I will happily talk to you and give advice but you are really need a professional to take a look from what
you have said.
Cheers Si.
http://s187.photobucket.com/albums/x319/zephyr2000/General%20forum%20uploads/?action=view¤t=3DEngine.mp4
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Strontium Dog
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| posted on 2/9/12 at 01:29 PM |
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quote:
Originally posted by cliftyhanger
Not a leccy, but first thing is it will deffo need to be fused down, really to 3 or 5 amps. That is what was done 20m years ago on my loft
conversion.
Otherwise there should be no real issues, unless the regs have outlawed fused spurs now?
You are only allowed a spur, fused or otherwise, on a ring circuit and ring circuits are only allowed for socket outlets definitely NOT lights! And
yes there is likely a few other issues to consider when installing electrical systems in a domestic (or any) environment!
[Edited on 2/9/12 by Strontium Dog]
http://s187.photobucket.com/albums/x319/zephyr2000/General%20forum%20uploads/?action=view¤t=3DEngine.mp4
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daniel mason
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| posted on 2/9/12 at 01:44 PM |
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not all of this is true. you can re-wire houses using junction box method if you want to. but the installation sounds bad as it is. why has he used a
2.5mm? why is the lighting main 'beefy'
shoulod be 1.0 or 1.5 mm2. i would NEVER certify a DIY job, EVER!
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cliftyhanger
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| posted on 2/9/12 at 01:49 PM |
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So lighting rings have gone? every light is now radial?
I guess there is/was a reason, but I am struggling to think of one. Unless it is something to do with bathrooms now needing their own mcb for the
light? or something like that from what I have picked up.
Re the spur in my house, I was just referring to what was done on my place. And as a reassurance, lighting rings still passed my safety certificates
when they were last done, so not dangerous. 90%+ of the country still has them (at a guess!)
[Edited on 2/9/12 by cliftyhanger]
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Strontium Dog
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| posted on 2/9/12 at 01:54 PM |
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quote:
Originally posted by daniel mason
not all of this is true. you can re-wire houses using junction box method if you want to. but the installation sounds bad as it is. why has he used a
2.5mm? why is the lighting main 'beefy'
shoulod be 1.0 or 1.5 mm2. i would NEVER certify a DIY job, EVER!
Not if they are spurs or stars you can't on a lighting circuit. Size off cable is irrelevant if it is big enough, it's the size of the
protection that counts. And you can't cert someone else's installation anyway, period! This is something I took up with my registering
body when I had to go in behind an incompetent electrician. Whole house had to be rewired as I was not able to asses the rigors the cables might have
been subjected to during erection! End of! According to NICEIC anyway!
If you want to risk certing another's work then on your own head be it, other than periodic inspection etc but NEVER an installation cert!
http://s187.photobucket.com/albums/x319/zephyr2000/General%20forum%20uploads/?action=view¤t=3DEngine.mp4
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Strontium Dog
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| posted on 2/9/12 at 01:56 PM |
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quote:
Originally posted by cliftyhanger
So lighting rings have gone? every light is now radial?
I guess there is/was a reason, but I am struggling to think of one. Unless it is something to do with bathrooms now needing their own mcb for the
light? or something like that from what I have picked up.
Re the spur in my house, I was just referring to what was done on my place. And as a reassurance, lighting rings still passed my safety certificates
when they were last done, so not dangerous. 90%+ of the country still has them (at a guess!)
[Edited on 2/9/12 by cliftyhanger]
I think you might be mistaken. You are not allowed to install ring circuits as lighting. They are required to be radial circuits!
Admittedly, I haven't worked as a sparks for about 3/4 years since I had to become a full time carer, but 16th edition and 17th as I am aware is
still the same re radial and ring circuits.
[Edited on 2/9/12 by Strontium Dog]
http://s187.photobucket.com/albums/x319/zephyr2000/General%20forum%20uploads/?action=view¤t=3DEngine.mp4
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Slimy38
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| posted on 2/9/12 at 02:02 PM |
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Interesting, thanks. The original wiring looks like it was done with the house, although it was a council house so it 'should' have been
checked on a regular basis until they bought it about ten years ago.
When I first looked at the box I'd not seen anything like it to be honest, but I did my sparky training back when I was still on my
apprenticeship, about twenty years ago now. It is a bit difficult to describe, while I can only describe it as a junction box it's not the round
things that most people would recognise. It's about ten inches square, with a large block at the bottom where all the lives and neutrals come
into, then a block on the right where each of the switches come into. Does that sound familiar to anyone?
It does sound like tapping on to that is the wrong approach, I'll have a look to see what other options he has. Although part of it may be my
misuse of the term 'spur', basically it's a single connection to the distribution unit rather than the double connection that a ring
main would use.
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Strontium Dog
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| posted on 2/9/12 at 02:05 PM |
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Here you go, this is quite clear
http://www.diynot.com/wiki/electrics:lighting:lighting_circuit_layouts
http://s187.photobucket.com/albums/x319/zephyr2000/General%20forum%20uploads/?action=view¤t=3DEngine.mp4
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Slimy38
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| posted on 2/9/12 at 02:19 PM |
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Yep, it's nothing like any of them!  I'll try and get a photo of it.
Although that link may have solved a particular problem of my own, I have a 'buzzy' lightswitch that I couldn't figure out how it
had been wired. Looks like it's the 'looping at switches' method so now I know where the wires going I can take a look at it.
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Macbeast
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| posted on 2/9/12 at 04:03 PM |
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So, if I read this right - every lighting point has to be run back ( via switch ) to the distribution board ?
Is that correct ?
I'm addicted to brake fluid, but I can stop anytime.
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JoelP
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| posted on 2/9/12 at 05:01 PM |
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This head makes me shake my head to be honest. If he doesnt know what to do, he shouldnt be doing it. And he has no chance at all of getting someone
to sign it off - its hard enough to get stuff signed off if its done according to the regs, nevermind if it looks diy.
Are you sure its an rcd feeding it all and not an mcb? If its an old house, it would only have an rcd if it had been rewired at some point, and it
wouldnt have an rcd feeding one circuit unless it was a recent modification.
A photo of the consumer unit would help you get advice, along with photos of the junction boxes and cables.
A light circuit is typically on a 6amp mcb, a big circuit might be 10a. If its a single light, then a 3a fuse in a fused connection unit would be
suitable. Cable would be 1 or 1.5mm t&e.
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JoelP
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| posted on 2/9/12 at 05:03 PM |
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quote:
Originally posted by Macbeast
So, if I read this right - every lighting point has to be run back ( via switch ) to the distribution board ?
Is that correct ?
No.
Typically there is a radial circuit running from the board, via every light, til it gets to the last one. There is then another cable carrying a pair
of brown cores (or sleeved brown) to the switch.
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Strontium Dog
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| posted on 2/9/12 at 05:53 PM |
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quote:
Originally posted by Macbeast
So, if I read this right - every lighting point has to be run back ( via switch ) to the distribution board ?
Is that correct ?
As Joel has said but look at the link I posted, here it is again
http://www.diynot.com/wiki/electrics:lighting:lighting_circuit_layouts
Although from a DIY forum, this does correctly show the usual ways to wire a light circuit. Additionally there are specific requirements for maximum
length of cable used in the circuit including the switch runs!
There is more to wiring a house than you may think and that's without understanding the building regs and how they effect for instance where you
can drill a hole in a beam.
[Edited on 2/9/12 by Strontium Dog]
http://s187.photobucket.com/albums/x319/zephyr2000/General%20forum%20uploads/?action=view¤t=3DEngine.mp4
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Slimy38
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| posted on 2/9/12 at 05:58 PM |
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quote:
Originally posted by JoelPAre you sure its an rcd feeding it all and not an mcb? If its an old house, it would only have an rcd if it
had been rewired at some point, and it wouldnt have an rcd feeding one circuit unless it was a recent modification.
A photo of the consumer unit would help you get advice, along with photos of the junction boxes and cables.
A light circuit is typically on a 6amp mcb, a big circuit might be 10a. If its a single light, then a 3a fuse in a fused connection unit would be
suitable. Cable would be 1 or 1.5mm t&e.
The board has been replaced at least once, I remember when my nan had it they still had fusewire!! So the consumer unit isn't as old as the rest
of the wiring. However, when it did get replaced they didn't do anything with the wiring, so there is ONE ring main for the house, and ONE
lighting main for the house. The one lighting main goes to this junction box (that I will get a photo of), then that goes out to all the switches and
light fittings throughout the house.
Since all the wiring for all the lights comes to the same place, (the centre of the house at the top of the wall), I might get him to replace the
single box with a series of junction boxes, one per light switch. That'll get it back to a radial circuit without too much trouble. I'll
have to get him to measure the house to make sure there isn't a square footage issue.
I'm not overly concerned about the wiring itself, it's all to spec or above. They seem to have used whatever they had spare as long as it
was big enough. As Strontium Dog mentioned below, the size of the cable is irrelevant as long as errs on too big.
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daniel mason
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| posted on 2/9/12 at 06:02 PM |
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it sounds like its just a standard junction box method to me! although old. i also know its the protective device thats important but anyone in the
know would not wire a 2.5 which is already fed from a 1.0mm.
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Strontium Dog
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| posted on 2/9/12 at 06:09 PM |
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quote:
Originally posted by daniel mason
it sounds like its just a standard junction box method to me! although old. i also know its the protective device thats important but anyone in the
know would not wire a 2.5 which is already fed from a 1.0mm.
I agree, but it's not technically incorrect or not allowed. A believe a warning label would be required at the point of origin as to the cable
used but I would have to look that up to confirm it. Appropriate labeling being a part of the requirements. Totally not what a professional would do
though for sure and I am with you on that!
As I said earlier, sounds like it needs a professional to asses it and may well and likely does need extensive remedial work!
[Edited on 2/9/12 by Strontium Dog]
http://s187.photobucket.com/albums/x319/zephyr2000/General%20forum%20uploads/?action=view¤t=3DEngine.mp4
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Slimy38
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| posted on 2/9/12 at 06:14 PM |
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quote:
Originally posted by daniel mason
it sounds like its just a standard junction box method to me! although old. i also know its the protective device thats important but anyone in the
know would not wire a 2.5 which is already fed from a 1.0mm.
It's just the junction box itself that has me worried, I'm only an out of date sparky but I'd not even seen that method of wiring!
And don't worry, it's not a 2.5 fed from a 1.0mm, as I mentioned in the original post they used something of quite decent size to get from
the consumer unit to the junction box, to me it looked bigger than 2.5 but was still only single strand(which would suggest it's 2.5mm max). But
in essence we don't have bigger wires downstream from smaller wires.
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Slimy38
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| posted on 2/9/12 at 06:16 PM |
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quote:
Originally posted by Strontium Dog
As I said earlier, sounds like it needs a professional to asses it and may well and likely does need extensive remedial work!
[Edited on 2/9/12 by Strontium Dog]
Already suggested it as soon as I started to see the responses! They're looking to rent it out so they need the certificates quite quickly.
I've suggested an initial review by someone better than me just to see what needs to be done, then I'll come back and assist with the work
before getting the final paperwork sorted.
I don't mind doing electrical stuff and consider myself reasonably competent, but I know my limits.
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Strontium Dog
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| posted on 2/9/12 at 06:22 PM |
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quote:
Originally posted by Slimy38
quote:
Originally posted by Strontium Dog
As I said earlier, sounds like it needs a professional to asses it and may well and likely does need extensive remedial work!
[Edited on 2/9/12 by Strontium Dog]
Already suggested it as soon as I started to see the responses! They're looking to rent it out so they need the certificates quite quickly.
I've suggested an initial review by someone better than me just to see what needs to be done, then I'll come back and assist with the work
before getting the final paperwork sorted.
I don't mind doing electrical stuff and consider myself reasonably competent, but I know my limits.
Get yourself a copy of the "17th Edition On Site Guide". As an ex sparks you will find most of what you need in there. The full regs book
is around £60 but the guide is just what it says it is and less than £20. It contains tabulated data on cable sizes, lengths, wiring systems,
protective device values etc. Basically all an electrically competent person needs to do the job.
http://s187.photobucket.com/albums/x319/zephyr2000/General%20forum%20uploads/?action=view¤t=3DEngine.mp4
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JoelP
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| posted on 2/9/12 at 06:44 PM |
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If they are renting it, just get a spark in to do an inspection and get him to sort it out at the same time. They arent that expensive! Not worth an
amateur fiddling about when a spark will do it twice as fast including filling in the paperwork!
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daniel mason
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| posted on 2/9/12 at 07:16 PM |
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unless when th spark gets there and finds no main bonds etc. then he aint gonna connect up and sign off!
imho i would also get someone in but it could open a serious can of worms as loads of remedial work could be required.
youd be amazed at some installations
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Slimy38
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| posted on 2/9/12 at 07:50 PM |
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Main bonds? Are you talking about equipotential bonding? That was covered when he replaced the kitchen, bathroom and central heating.
But I'm sure something else is going to come out of the woodwork... or in this case, plasterboard...
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