Installing electrics to shed

Discussion in 'Electricians' Talk' started by garmcqui, Apr 13, 2019.

  1. peter palmer

    peter palmer Well-Known Member

    Looks like PME so that needs looking at regards the earthing, also the 10mm connected strain to the henley block is pretty bad even though the main fuse is 60A.

    However regarding the banjo if I was doing it I would definitely put a banjo and bolt at the garage end because that is metal and a good earthing point and if I did it at the garage end I wouldn't do it at the plastic adaptable box end as well. And regarding flagging the cables, does a black cable really need flagging blue if it is clearly in a connector with a blue cable. Obviously it needs flagging at the garage end.
  2. Philip Hyde

    Philip Hyde Member

    Seen that a few times with lamp post cut out.
  3. garmcqui

    garmcqui Member

    So, I checked and the SWA cable is 10mm 3 core.

    There seems to be a little confusion as to the setup, so just to clarify...

    When the house was built, the feed for the garage was from a 2.5mm T&E spur off a socket in the living room, fed under a slab and into the garage.

    When we moved in in December, I asked a local electrician to upgrade the feed to the garage, mainly to cope with a 32A EV charger, so rather than take a feed from the main consumer unit, he took a feed for the garage (B) from the couneniently-placed meter box on the side of the house (A):


    Inside the meter cupboard, they spliced into the tails heading to the consumer unit using a henley block and 10mm T&E and used an IP55 enclosure to connect this to 10mm SWA 3 core:


    On the garage, a 2nd IP55 enclosure was used to terminate the SWA, and 10mm T&E taken through the garage wall into a 3-way MK metal consumer unit:


    Worringly, there doesn’t appear to be any earthing of the armouring at either IP55 enclosure. The glands used are these, are they suitable?


    There is an earth rod installed in the garage for the EV charger, whether this affects the entire garage earthing arrangement, I am not sure.

    So, am I right in thinking:

    I should get the armouring earthed, either by using a banjo on one of the glands, or perhaps by using a 20mm earthing nut?

    Regarding a supply for the shed (seen in the background), I am now thinking I could take a feed from the enclosure at B, and fit one of these beside the existing enclosure, to at least ensure the cable run is protected by an RCD...

    Any advice appreciated.


    Attached Files:

  4. Comlec

    Comlec Well-Known Member

    It would appear from your pics and notes that you are relying on the service cutout (Main Fuse) to protect the 10mm supply to the garage, unless I am missing something.
    garmcqui likes this.
  5. Philip Hyde

    Philip Hyde Member

    Whole list of problems
    Armoured not earthed
    Cables not identified properly
    10mm t and e not fault protected.
    Swa not terminated properly in gland.
    I'd get them back to it
  6. Comlec

    Comlec Well-Known Member

    From the pics it looks like the supply earth is being exported via the SWA( Black) to the garage.
    garmcqui likes this.
  7. seneca

    seneca Screwfix Select

    Yes it does look that way doesn't it Comlec!
  8. unphased

    unphased Screwfix Select

    If the supply is PME then you can either earth everything as a PME, including the shed OR separate the earth in the shed completely from the source PME supply and put a rod in for the shed. Personally I don't see any need for this. The 'exporting' of PME (a term I really don't like) is mainly of concern where buildings have extraneous conductive parts to contend with including bonding. If your just supplying a garden shed with a socket and a light its daft to put a rod in for that. Just leave it all earthed on the PME. It is NOT dangerous at all and I suggest your concerns about 'exporting PME' are misguided. The main concerns I would have with this particular circuit are already highlighted. Shoddy workmanship, lack of attention to detail and incorrect installation of glands such that the armour is not earthed. The rod put in for the electric vehicle charger should be just for that alone. There are special rules for earthing EVC's and one of them is PME isn't allowed.
    garmcqui likes this.
  9. garmcqui

    garmcqui Member


    What should have been done? Or what can I ask them to do to rectify this? Inline RCD in the meter cupboard?
  10. Philip Hyde

    Philip Hyde Member

    Needs a Rcbo. RCD dosent offer overload protection of the cable.
    garmcqui likes this.
  11. Bazza

    Bazza Well-Known Member

    Doesn’t need the RCD function. But it must be fused. A KMF switchfuse would do it.
    Add that to the long list of remedials that are needed just to regularise the existing lash-up.
    garmcqui likes this.
  12. seneca

    seneca Screwfix Select

    It doesn't have to be an rcd as it's swa cable, the rcd can go at the far end but there should be a fuse or circuit breaker at the supply end, a 32 amp fuse/mcb would probably be appropriate, can't be certain without knowing cable size and expected loading.
    garmcqui likes this.
  13. Bazza-spark

    Bazza-spark Well-Known Member

    But the wire armouring does need to be earthed.

    Kind regards
    garmcqui likes this.
  14. seneca

    seneca Screwfix Select

    Yes, most definitely!
    garmcqui likes this.
  15. garmcqui

    garmcqui Member

  16. Bazza-spark

    Bazza-spark Well-Known Member

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