Break in ring main


Postby cinn » Fri Dec 16, 2011 6:00 pm

Having had a new Consumer unit fitted, the electrician informed me that, upon testing, he was not getting any continuity from the kitchen outlet sockets suggesting a break in the circuit. The kitchen is a former stable that abuts the gable end of the main house. There are 4 double outlets - 2 on either side.Upon my investigation it appears that the break is between the 2nd and 3rd which are on opposite sides. All 4 function correctly and, to all intents and purposes, we now have 2 radial circuits with 1st and 2nd fed from one direction and 3rd and 4th from the other on the ring. As all the wiring is embedded in the wall render and we have just installed a new kitchen and tiled the walls - is it feasible to: disconnect cabling between 2nd and 3rd socket; drill through wall behind both sockets to the outside; run a new cable outside into armoured conduit; around outside of kitchen; then back into a utility room behind kitchen (also formerly part of the stable); out again into armoured conduit and into the other socket????
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Postby ericmark » Sat Dec 17, 2011 3:10 pm

Yes you could connect using armoured cable. However the normal way is to replace the 32A MCB with a 20A MCB and just disconnect the faulty cable. If there is room in the consumer unit then 2 x 20A MCB's could be used. This would depend on the loop impedance measurements. If it was originally near the limit then 16A MCB may be required.
I am assuming since you know there is a fault he tested the sockets. So I would assume you would have the paperwork giving the loop impedance? For a ring we normally look as less than 1.44 ohms at centre socket. Reducing the MCB to a B20 will allow the impedance to raise to 2.3 ohms. A B16 will allow it to go to 2.87 ohms.
With a new consumer unit likely all RCD protected so the earth - line loop impedance can be very high it's the neutral - line impedance which is important. This will also effect the volt drop.
What I can't understand is why the electrician doing the work did not advise you on the best way forward? Also I would assume the MCB/RCBO has already has been reduced in size no electrician should re-instate a broken ring using a 32A MCB.
Also I would have wanted to have isolated the faulty cable. Can't understand why the electrician has not already done so?
So what is the problem? Has he not finished the job?
The electrician needs to issue a number of certificates. I would expect he would use an installation certificate but he could issue a minor works certificate instead. Likely he would also have done an inspection so you would have a periodic inspection report or electrical condition report two names for same thing. But the really important one is the completion certificate which his scheme operator will forward to you and local council. Can't see how he could issue that without doing something about the ring fault?
If he has done something like fit two MCB's and turn into two radials then to turn back into a ring would need new paperwork issuing. After of course more tests.
So question has to be why do you want to make it a ring again?
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Postby cinn » Sat Dec 17, 2011 7:42 pm

Thanks for reply. No he didn't test the sockets I did yesterday by trial and error. The electrician who installed and tested consumer unit said he would discuss the matter with his boss. That was over 2 weeks ago and i've still heard nothing and received no certification or written report. The mcb installed on what should have been a ring is 32. He did mention setting up as 2 radials but as they have not been very good at keeping or making appointments I was considering getting another electrician to finish off - although obviously I still need the certification from the original electricians. I don''t really know what would be best - 2 radials or repair the ring in the manner of my original post. I will see if I can get the data from them, but to be honest I'm sick of continually having to chance them.
cinn
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Postby ericmark » Sun Dec 18, 2011 9:54 pm

If you can have two radials that is the way to go. I would agree not very clever finding a fault and then not making safe. I would have fitted a 20A MCB not a 32A once I knew the ring was broken. Maybe I would not have fault found and would have just noted but he never should have fitted the 32A MCB.

If I was his boss I would not have been amused. Clearly he can't issue a completion certificate until corrected in some way. This leaves him with a problem. I have been there myself and it's a big problem with domestic. We are not allowed to make a house uninhabitable but neither are we allowed to re-instate something which is dangerous. This is why most electricians will test before they start so faults like this can be agreed as to how to get around before we are faced with breaking rules what ever we do.

However you also have a problem in that you can't move on using another electrician until you get paperwork from the first. I really don't know what to advise.

I hope Sparx or one of the other electricians on this forum who are members of a scheme will come in and give advice. I think unless they say otherwise I would be ringing the scheme provider and asking them for help. I think he has 14 days to provide paperwork. Again maybe others can help here. Clearly if not already paid then I would not pay until sorted in some way.
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Postby cinn » Mon Dec 19, 2011 5:34 pm

Thanks. Unfortunately, I have already paid him in cash (gentleman's agreement) for the fitting of the consumer unit - rather stupid / trusting of me really. I would be grateful if someone in the scheme could give me some advice as to how to proceed re: outstanding paperwork. Cheers.
cinn
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Postby ericmark » Tue Dec 20, 2011 9:25 am

There are two ways. First is to contact his scheme provider. NICEIC, ELECSA, NAPIT, ECA, CORGI or other name should appear on his van or paperwork. Google "competentperson.co.uk/" to find who is registered with whom. Careful with name competent person it was a bad choose of name as under the HSE definition I am a competent person but I am not a member of a competent persons scheme.
If you are unable to sort it direct with scheme provider then next is the local council.
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Postby ericmark » Tue Dec 20, 2011 10:36 am

Sorry having problems with keyboard so cut short. I am hoping your guy is a member of a scheme! If so there should be no problem. However if he is not a member of a scheme then the process is a little grey. It is the responsibility of the owner to inform the LABC although in most cases the electrician or builder will do it for you. If the electrician claimed to be a member of a scheme but was not many councils have come down hard on them and taken them to court. Specially if there was bad workmanship as well. But there is a problem if he did not claim to be a member of a scheme. He should scheme member or not issue an installation certificate which you as the owner could present to council to get the completion certificate. However when going down that route the LABC should have been informed before not after the work was started. There is an exemption for emergency work so if for example the consumer unit had been smashed then you can inform council after the event.

I had a builder with my parents house run off into the hills of Wales leaving me and my son to pick up the pieces. I informed LABC we would be taking over the work only to find they had not been informed of it in first place. They told me I could not proceed until I got their go ahead but I pointed out emergency clause and then I was permitted to start. Luck as work for disability in my case no charge. The firm who has started the work stopped trading. Don't know if this was due to council or not. The electrics side of the job was quite a problem as the council would not accept my sons signature on paperwork. Lucky they did accept mine. I had to use a triple signature form for the installation certificate and marked on it what the previous guy had done and left the signatures for that part of work blank. I did in the end get the completion certificate from the council.

From what I can understand where some one walks off without issuing certificates the only option is the council (LABC) as another electrician has no way to know if the stuff done by first guy was correct. So unless the new guy ripped out all the work done by last guy and re-installed it he can't sign the installation certificate. The council however will often issue a completion certificate on the receiving of an electrical condition report (was called a periodic inspection report) and often this is the way forward.

Please report on how you get on. It helps others in the future. As electricians our dealings with LABC are very different to Joe Public so since you are not trying to DIY you may find a different attitude to what we get. Some councils use selected electricians to do work for them and it is possible they can point you in the right direction as to some one who with the LABC blessing can issue the certificates required.
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Postby cinn » Fri Dec 23, 2011 7:39 pm

Thanks very much, your advice/info to date has been helpful and illuminating. I decided to set my wife on him and he has grovellingly agreed to come round after Xmas to discuss test findings after claiming to have been working away in Scotland - I await his materialization with excited anticipation. I know that some of the earth continuity readings were high (don't know what they were though) and there is a 'shared neutral somewhere' (I believe it is in the 2-way landing light switch). I have been trying to gen up so that I am not bamboozled by him when he turns up. My house is 200 yrs old (only been here 6 months) and the previous owner seemed obsessed with adding spurs (in some cases spurs to spurs - I have disconnected some recently). It is my understanding from reading other articles on the forum that under these circumstances higher readings are not unusual - is that correct? The guy is in a scheme as he does a lot of work for and came to us through a plumbing company owned by a relative of a friend of the family - which is why, up to now, I have tried to remain patient and not get nasty, but obviously the issues at hand are important and my patience is not limitless. I will keep the forum informed as to future developments.

Cheers
cinn
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Postby ericmark » Sun Dec 25, 2011 12:21 am

I expect this will not appear until after today Christmas day but here goes.

Spurs on spurs easy cure is a fused connection unit FCU so all after the unit are on a single 13A fuse. In the main his makes it safe although of course you may blow the fuse from time to time.

As to borrowed neutral although that's correct name really a borrowed line. Instead of running 3 core and earth years ago we ran two core and borrowed the line from next switch with a double switch. This caused problems with radios etc. buzzing. It worked OK. As people tried to add more and more lights they went over the 6A limit for ceiling roses so they split up-stairs and down-stairs. However this then caused the borrowed neutral. Cure is easy with energy saving lamps 6A is ample so just combine the two light circuits again and it will comply. If losing all lights produces a danger you may need an emergency lamp but that's easy to fit.

It is a problem trying to balance common sense and the regulations. Having some one who is not OTT following the regs can be an advantage. As long as he issues the paperwork he may be a lot better than some one who wants to always follow the rules.
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Postby sparx » Mon Dec 26, 2011 4:05 pm

Hi, just back myself so catching up with posts.
Agree with Ericmark as usual, make 2-20A radials poss. best answer, making sure unused link made safe from accidental contact in outlet boxes.
As for 'borrowed Neutrals' on lights, imho leave as 2 circuits - no problems as long as both on same RCD half of board.
Only really an issue if using all rcbo's then no easy way other than making as one circuit.
Can understand his reluctance to spend time finding ring fault at the time of board change if he was booked up every day.
I have recently had same problem, since I allow one day for board change, including any earth upgrades needed and to complete test sheets as I go;
no time to find 'open ring' but don't want to issue test cert with 'failures'. went back a few days later and owner had remembered a half done extension to ring in loft for aerial amp. and put back as original, circuit tested fine!
Insist on cert even if with exception comment to kitchen circuit then another sparks should be happy to do remedial work and issue a minor works cert.
First company can also register job with LABC even with exception on cert.
regards Mac-Sparx
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Postby cinn » Thu Dec 29, 2011 10:37 am

Thanks guys that's brilliant advice and much appreciated. At least now I have info to be able to get the problems remedied without getting blinded by science.

Cheers.
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Joined: Fri Dec 16, 2011 5:35 pm


Postby cinn » Fri Jan 13, 2012 11:42 am

As promised here is an update on situation. After a little gentle reminder electrician finally got back to me today (so much for after xmas - although technically it is). He wants the guy who did the test to come round and explain it and talk thru options. I have told him I want 2 radial circuits to resolve kitchen ring but apparently there was also a problem in that he couldn't find the earth end line on a lighting circuit to do the impedance test. The kitchen lights are not earthed at all which we had already discussed with him. This is an old house and I reckon the previous occupants re-wired in 1985. I have changed several light fittings up stairs and down in main house and earth present in all but toilet where either switch or light (can't remember which) didn't have earth cable. Presumably this means that the circuit would trip the mcb but not rcd. As older houses didn't used to have earthed lighting and I've already agreed not to do anything about the kitchen (just to have the situation noted on the certificate of completion (if it ever materialises)), what is the significance of this?? Am I missing something fundamental?? Or could the same comments be added re this circuit as well?

p.s. sorry for rambling

regards

Cinn
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Postby sparx » Sun Jan 15, 2012 9:35 pm

Cinn
with regards to the lack of earths at lights, this is so common that there is a label made for putting on the consumer unit stating:
"Circuit(s) XYZ have no earth, therefore only all-insulated fittings should be used".
ie no metal lights/switches on unearthed section of these circuit(s).
As for the open ring circuit, leaving 2 radials on a 32A mcb is not satisfactory and the cert. should be marked as such! this is an overload/fire risk so cannot be marked as satisfactory.
If there is room for another circuit in the consumer unit then changing to 2 20 radials is one option or if no spare 'way' then whole circuit needs down grading to 20A,
or best still find open circuit point and rejoin as original .

regards Sparx,

P.S. why did original 'electrician' have to get someone else to do testing? is he not registered? if not he shouldn't be doing domestic work anyway.
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