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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

  • 0
    From Electrical Safety First's Best Practice Guide 4, in the section on examples of C3:

     
    Sheath of an insulated and sheathed non-armoured cable not taken inside the enclosure of an accessory, such as at a socket-outlet or lighting switch. (Note: Code C2 would apply if unsheathed cores are accessible to touch and/or likely to come into contact with metalwork).

     

    Although as Colin says, I'd reserve judgement until I'd seen a photo or two.
  • Former Community Member
    0 Former Community Member
    Although as Colin says, I'd reserve judgement until I'd seen a photo or two.


    Photos tomorrow


  • 0
    Unsheathed cables touch metalwork all the time inside trunking or conduit. What does this comment mean? It is unusual for me to agree with the "coding books" but in this case, we seem to see the same level of danger although they also seem to not want them to be touched. Most curious.
  • 0
    One of the problems with partly punched knockouts in metal enclosures is the tends to be to little knibs that can snag insulation more so than the rest of the metal edges.


    Also even if the insulation is only scored rather than severed it can open up whilst it’s being manipulated, so you really do need to be cautious.
  • 0
    davezawadi (David Stone):

    Unsheathed cables touch metalwork all the time inside trunking or conduit. What does this comment mean? It is unusual for me to agree with the "coding books" but in this case, we seem to see the same level of danger although they also seem to not want them to be touched. Most curious.




    What is the code for a lid missing off trunking allowing contact with the single insulated conductors?


  • 0
    Sparkingchip:

    What is the code for a lid missing off trunking allowing contact with the single insulated conductors?


    Oh dear, I took a lid off a metal BESA box earlier, but didn't put it straight back on. It couldn't be more than C3, but I think that the consumer's tails about which we have been talking are different.


    The cables in my conduit are secure and cannot be pulled; there are no rough edges; and they have additional protection.


    The problem with the semi-naked tails is (assuming they are just dangling, as is typical) that they could be pulled against the (presumably) rough edge of the CU. In the event of a fault, the only protection is the DNO's fuse. If they have already been pulled out of the CU, even if only 3/4", they do not seem to be very well secured.


    But hang on a moment, we haven't been told whether the CU is metal or plastic!


  • 0
    C3 is "requires improvement" as I am sure you realise

    Again I differ - C3 is merely "improvement recommended" according to BS 7671, not at all the same as improvement required. By saying it's a C3 you're claiming the installation is actually satisfactory for continued use despite such a non-compliance - a conclusion I definitely wouldn't be comfortable with.

       - Andy.
  • Former Community Member
    0 Former Community Member
    Metal
  • 0
    Colin Haggett:
    Zoomup:


    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.


  • 0
    Zoomup:
    Colin Haggett:
    Zoomup:


    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.


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