Rules and Guidelines
Want to participate in the discussions? Please read our Community Rules and Guidelines. Need some help? Visit Support and Answers.

  • State Helpful Answer
  • Locked Locked
  • Replies 16 replies
  • Subscribers 40 subscribers
  • Views 6874 views
  • Users 0 members are here
Options
You may also be interested in
This discussion is locked.
You cannot post a reply to this discussion. If you have a question start a new discussion

Very long meter tails - is this proposed arrangement OK?

Chris Kessell

I would be grateful if someone could give this a sanity check...

We live in a bungalow, and the electricity meter and consumer unit are currently located side-by-side in an internal cupboard.  The DNO (Western Power) service cable to the house runs from an overhead line to the gable end of the bungalow and then around the external walls and into the back of this meter/CU cupboard. 

However, we're planning an extension which will require the service cable to be relocated because part of the wall it runs along is to be demolished.  A team from the DNO has visited to discuss the matter.  

We had hoped they might be able to simply reroute their service cable through the loft space to the existing meter location, but this isn't permitted.  However, they explained that the meter tails are our responsibility and hence could be run through the loft.  Hence their proposed solution is to fit an external meter box to the gable end wall of the house, relocate the meter into that, and run the meter tails through the loft space to the CU.  The distance from meter to CU would then be about 15m.

This arrangement was proposed by the DNO so I assume it's OK, but I have read (including in the DNO's own guidance literature) that meter tails should be no more than 2-3m long.  Ours would be at least 15m long!  So does their proposed solution sound reasonable?  Are there any potential issues I ought to be aware of?

  • 0 in reply to tattyinengland

    and that is the sort of thing that really will only trip when you need it to. 

    You could argue the same single point of failure about the 100A supply fuse.Very few folk argue for its omission - well perhaps those wiring up dope farms ;-)

    A row of 300mA delay RCDs one  per SWA submain out, is actually quite a sensible and common TT arrangement for rural factories farms etc.
    Mike

  • 0 in reply to Chris Kessell

    Around here we can get  a P.M.E. earthing terminal installed by U.K. Power Networks even for overhead supplied properties.

    Z.

  • 0 in reply to mapj1

    You would surely agree Mike that a 100 Amp cartridge fuse is not as sensitive as an R.C.D., and liable to disconnect for numerous, (not always identifiable) reasons. Even time delayed "S" types can disconnect for no apparent reason.

    I had an upfront 100mA "S" type R.C.D. trip off when supplying several R.C.B.Os in a new consumer unit in a modest bungalow. I never found out why. It got changed to a 100 Amp. D.P. switch after the installation was converted to P.M.E. earthing.

    Z.

  • 0 in reply to Chris Kessell
    Chris Kessell said:
    As it happens the earth rod will also need to be relocated as it lies under the proposed extension; the DNO agent suggested putting the new rod below the new meter box for cabling convenience.

    Or you could put in a foundation electrode. I am bound to wonder why one would not do so when the opportunity arises.

  • 0 in reply to Chris Pearson

    An individual earth rod is easier and less expensive to install Chris.

    Z.

  • 0 in reply to Zoomup

    not if the extension is yet to  be built - they will be digging holes for the foundations anyway, and if there is rebar or steel piling involved then to weld to it in a couple of places is very fast.
    M.

Join us to get the best from IET EngX.

Joining EngX lets you personalise your experience so you stay up to date on the topics that interest you, plus you’ll be able to make connections who are looking to collaborate, exchange ideas and more.

Join us Not now

Community Rules & Guidelines