DIY PME ?

Discussion in 'Electricians' Talk' started by Steven2011, Aug 14, 2017.

  1. Steven2011

    Steven2011 Member

    Hello People,

    I have been to look at a property and came across this setup (picture attached). I know it's not nesasarily wrong as it's PME but it just doesn't look right to me and is usually done at the origin (main fuse). Main fuse being located in the corridor in a locked room.

    Not done any proper testing on the property yet, done a few earth loops on the sockets which are testing fine.

    Should I get the suppliers involved or do we think it's ok? Suppliers have left their tags on, so appears they are happy with it... ?

    Thanks

    image2.JPG
     
  2. unphased

    unphased Screwfix Select

    Steven I don't like the look of that setup. For starters there is only basic insulation on the tails going in to the meter and there should never be just basic insulation exposed on meter tails, they need to be insulated AND sheathed. Secondly I agree with you that the earthing is irregular. If I were you I would ask for confirmation from the DNO that there is a proper PME entering the property and verify that first. Then ask them to comment on that arrangement it isn't safe in my opinion.
     
    Steven2011 likes this.
  3. sparky Si-Fi

    sparky Si-Fi Screwfix Select

    Wheres the Fuse and cut out, its supposed to be in close proximity to that

    Thats Straight concentric, straight into a meter!
     
  4. Steven2011

    Steven2011 Member

    The owner contacted the DNO who has said the fuse is within a locked room in the landing. It doesn't look right to me either and I'll contact the DNO myself. :eek:
     
  5. Steven2011

    Steven2011 Member

    Hello! Yeah doesn't look good for me either! I'll contact them and see what they say.
     
  6. Bob Rathbone

    Bob Rathbone Screwfix Select

    PME is reserved for supplies only, it cannot be used for a sub main unless permission has been granted from the Secretary of State for Power, or whoever succeeds this post. You will be familiar with the rules for this type of supply and how the 'multiple earthing' part of the system protects the user from a broken neutral. Others have commented on the exposed basic insulation, I have seen this on other DNO jobs, but never a missing service fuse. Could this be a sub meter?
     
  7. nigel willson

    nigel willson Screwfix Select

    Single pole blocks that are sealed suggest DNO!?
     
  8. mhar

    mhar Member

    If the fuse is in a locked room on a landing then it suggests that this is flats and then the supply issue to this unit lies with the BNO, not the DNO.
    The BNO is likely to be the freeholder. A lot do not realise they are Building Network Operators.
    The DNO will have provided whatever means of earthing (if any) is suitable for the network to the cutout in the locked room and that is where their responsibility is likely to end. Distribution from that point is likely to be outside of the DNOs remit and what is pictured appears to be non compliant.
    Seals could well be from the meter fitters and cannot be considered as an indication of compliance.
    Is it in an HMO?
     
    unphased likes this.
  9. sparky Si-Fi

    sparky Si-Fi Screwfix Select

    The Straight concentric cable used in that pic is used by Western Power/DNO/REC ETC.

    Unlikely this is any form of Final circuit/Sub
     
  10. mhar

    mhar Member

    I believe that it is only since the 17th edition that concentric and split concentric have not been recognised by BS7671. Pre the 17th it was not unusual to see it used in distribution circuits.
    Picture does not look like dno work.
    Would be nice to be updated
     
  11. Lectrician

    Lectrician Screwfix Select

    Straight concentric was never recognised in our regs. Split concentric was and still is. It is no longer a cable that can be used to provide penetration protection, but still a cable that can be used, but must be treated like twin and earth. The old regs used to allow split concentric to be buried in a wall out of zones due to the concentric covering. The regs no longer recognise this.
     
    mhar likes this.
  12. JP.

    JP. Screwfix Select

    Whats the point of using split con Lec? - it seems a very contradictory type cable tbqh..is it old hat?

    Cannot see any logical use for it really - but hey ho
     
  13. Lectrician

    Lectrician Screwfix Select

    Treat it as T+E.

    Benefits over T+E?

    It's black.
    It's round.
    It's easily clipped and cleated.
    It's easy to form bends.
    It glands nicely in TRS glands.
    It's easier to pull through than flat cable.
    It looks far better than T+E when clipped direct.

    It is ideal for internal submains in most situations. RCD protection aside.
     
  14. JP.

    JP. Screwfix Select

    Thanks for the explanation Lec - all appreciated
     
  15. mhar

    mhar Member

    Plus comparitively high current carrying capacity (16mm nearly 100A in free air, more when buried) and it is self supporting (for overhead spans)
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.
    Dismiss Notice