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Ring Main at Consumer unit

Former Community Member
Former Community Member
My daughter has just had an electrical safety check done and I suspect that the electrician has been over zeleous..

Would anyone care to comment.


There is no grommet where the meter tails enter the consumer unit and the outer insulation stops just short of the knockout.

He has graded this C1.   Now my opinion is that that does not present an  an immediate threat to the safety of personell

It needs fixing but surely only a C2?


More intriguing.  He gives a C3 to the ring circuit because the two legs enter the consumer unit through separate knock outs.  I can't find that in the regs


And finally an old chestnut which has been discussed before.   A C3 because two radial "circuits" are served by a single breaker..  I have always argued that the definition of a circuit is that it is served by a single breaker.  Certainly if both radials were brought to a junction box outside the CU and then connected to the breaker by a single cable it would meet the definition of a radial..


Thanks for your attention

  • Colin Haggett:
    Zoomup:
    Colin Haggett:
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    I agree that the removal of only sufficient outer sheath in order to be able to identify the tails is best, but I fail to see a problem with removing more inside the CU: it does reduce the bulk.  


    Hear, hear, well said Chris. Also the modern carp tough copper meter tails are difficult to bend easily. Whatever happened to the nice easily bendable stuff? I normally do the sharp bends and then afterwards cut the strands all off square with my BIG cutters, as they come out of alignment after bending. Don't yer ands ert after manhandling modern tails?


    Z.


    25mm flexible tails are widely available coloured brown and blue. 




     




    Many wholesalers just give us the tough difficult to bend stuff. I have even seen a meter installer complaining about the tough rigid stuff he has to use as well. Perhaps its the cheapest, in more ways than one. Which type are you referring to please?



    Z.




    I use Flexi Meter Tail Pack 25mm 6181Y Brown & Blue (19 Strands) 16mm 6491X Green Yellow. Just ask for a flexi tail pack miles better to use. Getting expensive now with copper prices going up every week.




    Thanks Colin, that sounds like a good solution.


    Z.


  • I am beginning to lose it over this thread.

    Andy is suggesting that ANYTHING which is not compliant is at least a C2 for some reason, eg a Plastic domestic CU. No Andy that is not correct, in fact, it is worse than that, it is utter rubbish. If your saying were true, there could be no C3 could there? The only one possible would be the "I don't like the look of that" comment, whit no deviation from the regulations! Insulated conductors are not dangerous as such, they could be damaged, but so can sheather cables. By the sound of your thought andy "clipped direct" is now a C2 because damage is POSSIBLE. This is not the spirit of the regulations, they are primarily about safety and how to achieve it. Exact non-compliance is not a requirement for existing installations (in other words 100% retrospective in action).


    So far no one has made any reasonable case against my coding of the exposed insulation, including Electrical Safety First. It appears that if you use unsheathed meter leads you are now in danger of DEATH. Obviously not, strangely now YOU are all DEAD! Hopefully not, and therefore you understand that primary insulation is perfectly safe to be handled. I do appreciate the comment "C3 then nothing will be done", but ensuring that is NOT the Inspectors job. He must just produce a report, hopefully of excellent quality.


    I have had 3 people this week send me information and asking for opinions. I will help where I can (FREE) but cannot always produce definitive answers. However it is a strong indication that the EICR process is seriously broken, and I intend to try and fix it. Support always welcome, it is presently getting electricians a very bad reputation.
  • Afraid that I tend to agree with Andy.


    C1 = danger present e.g. live conductor of tail is exposed.

    C3 = improvement recommended e.g. tails identified using old colours.


    C2 = potentially dangerous i.e. somewhere between C1 and C3.


    What we do not know is whether the basic insulation was visible at the time of installation or only afterwards: the OP suggests the latter. At the very least, I would have a good look at the route of the tails within the CU and their terminations.


    If the tails have been moved by a meter operative, they should not have been; but they do take liberties. A few days ago, I was checking my installation prior to annual assessment. The earthing conductor and CPCs to the two DBs were wonky. The meter operative who had installed a smart meter had moved the MET. ?
  • Am still C2, you’ve got basic insulation passing through a hole in a metal consumer unit without a grommet. It’s potentially dangerous, it might be a remote danger but it’s there and needs improvement. You have two layers of protection missing, the next is a big bang and a flash.
  • Unsheathed cables touch metalwork all the time inside trunking or conduit.

    But the point is that they are inside containment.

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    Unlike the above.


    One reason cables are insulated and sheathed or insulated and in containment is to reduce the risk of the basic insulation being damaged, exposing the copper.

    So it follows that if you cannot be bothered with containment or a sheath, that has the potential for danger.


  • Colin Haggett:

    Am still C2, you’ve got basic insulation passing through a hole in a metal consumer unit without a grommet. It’s potentially dangerous, it might be a remote danger but it’s there and needs improvement. You have two layers of protection missing, the next is a big bang and a flash. 


    Is the tail touching the metal, pressing on it perhaps,  or is it centrally positioned in free air?


    Z.


  • You are doing it now Chris.

    Tails identified with the old colours are not a C3 by any reasonable test. There should be a label saying that mixed colours may be present, quite why that is needed is also dubious now, although when the change took place perhaps necessary. There is no need whatsoever to improve the wire colour codes. A black/red cable from a switch drop should have a red or brown sleeve on the switched live (black) but this may be given a C3, it is somewhat inconvenient when a ceiling rose is replaced. C2 is not somewhere between a C1 and C3 either, it is for potentially dangerous as you know very well, which the examples above are not, at least in the normal sense of danger. C3 is for regulation non-compliances which are not dangerous if you like that definition. A plastic CU in a domestic is not dangerous, it is potential loose screws which may be, so we code it as a C3. The inspector should check the screws and is then sure this problem is not present in the CU, thus C3. A plastic CU is perfectly permissible in other premises, so this requirement is somewhat anomalous, however, we seem to have it.


    It is this kind of discussion caused by this thread, which shows up shortcomings in our EICR procedure very clearly, and this is only for a simple domestic installation, not a much more complex one elsewhere. It is why the experience of the inspector is very important, and why he needs to set the standard in the right place. That place is not "Is there any conceivable way this could be dangerous", and must be "is there any reasonable way this defect could be dangerous" DUE only to that defect. If one adds damage etc. on top of the defect, everything is dangerous, one must use a reasonable likelihood for damage. This is usually firmly indicated by the installation method and accessory construction, for example, steel conduit and metal-clad fittings. Without this clipped direct wiring must always be given a C2, as damage is reasonably possible by accident and deliberate action.


    Many of the EICRs I see that are "excessively coded" are because this threshold is not understood, it may be deliberate, but I am sure that many are due to misunderstanding, in fact, some of the electricians concerned seem genuinely surprised that their EICR is too harsh. It becomes much clearer when their own work is examined and coded in the same way, minor deviations being just slightly imperfect work. The tails in question may have been pulled quite hard because they were rather short to reach the new meter terminals, which might well be the cause of the requirement for metal CUs in the first place. The problem is caused by poor management of meter installers, they do not have Henly Blocks available and are not supposed to open CUs. How is the problem of short tails resolved?


    Looking at Youtube has become somewhat horrific. There are a number of videos on CU changes, the look of the job is obviously of great importance to the posters, all neat and straight and square wiring etc. Lovely. Is this specified by BS7671? Not really, nothing wrong with tidy work, but in most of the videos, it is obvious that none of the old wiring is being used. Not a CU change then, but a complete rewire or extension of the old wiring (which they do not show). That is the job that separates the men from the boys.


    You may find it interesting to listen to the Grenfell tower inquiry videos on youtube, running daily at the moment. It is very legalesque, but some bits are interesting in that so many steps, in the safety inspections were not followed properly. It is not that they were just poor inspections, it is the follow-ups that are poor, to say the least. Several other points have also shown up, inadequate training, false claims of competence, false qualifications (or ones which were not held listed as post-nominals, letters after the name), all of which are commonly committed by some electricians. I wonder how many of you are "Registered Electricians"  (used by a local firm)? You may be registered with a competent person's scheme, but that doesn't have the same ring about it, does it?

  • “The problem is caused by poor management of meter installers, they do not have Henly Blocks available and are not supposed to open CUs. How is the problem of short tails resolved?”


    Easy, fit an isolation switch between the consumer unit and meter, replacing the tails between the isolation switch and meter if required.


    But that makes too much sense.
  • Sparkingchip:

    “The problem is caused by poor management of meter installers, they do not have Henly Blocks available and are not supposed to open CUs. How is the problem of short tails resolved?”


    Easy, fit an isolation switch between the consumer unit and meter, replacing the tails between the isolation switch and meter if required.


    But that makes too much sense.


    What? Free of charge?!!!


  • davezawadi (David Stone):

    You are doing it now Chris.

    Tails identified with the old colours are not a C3 by any reasonable test. There should be a label saying that mixed colours may be present, quite why that is needed is also dubious now, although when the change took place perhaps necessary. There is no need whatsoever to improve the wire colour codes. A black/red cable from a switch drop should have a red or brown sleeve on the switched live (black) but this may be given a C3, it is somewhat inconvenient when a ceiling rose is replaced. C2 is not somewhere between a C1 and C3 either, it is for potentially dangerous as you know very well, which the examples above are not, at least in the normal sense of danger. C3 is for regulation non-compliances which are not dangerous if you like that definition. A plastic CU in a domestic is not dangerous, it is potential loose screws which may be, so we code it as a C3. The inspector should check the screws and is then sure this problem is not present in the CU, thus C3. A plastic CU is perfectly permissible in other premises, so this requirement is somewhat anomalous, however, we seem to have it.


    Well, C3 if there is no colours notice. I must say that Daughter was somewhat alarmed when I slapped a "WARNING" notice on her CU. ?


    Notice or not, there is no need to replace the tails (or other cables) - just put those coloured (+/- lettered) cable ties around them. Not too difficult to rectify the grommet and sheath either.


    I fully agree that a plastic CU (at home) is only C3 (the power to this tablet arrives via one) but what of those loose screws? In testing them, do we not tighten them? Or having found them loose, do we return them to the condition in which we found them? Yes, that's a bit absurd!