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Insulation and thermal bridging and an EV charger

JohnE

The situation is a garage being converted into a TV room

External wall with batten attached which is to be insulated with 75mm PIR insulation and plaster boarded
Stud is only 70mm!!

Picture attached...

The house CU is high up on the wall. the tails ran down the internal garage wall to the outside meter box
A second CU was mid way down the wall feeding  an external EV charger, the tails of which also went to the external meter box

The tails were in plastic conduit surface mounded.

Since the tails (no RCD protection)to both boards are to be hidden by the plasterboard, I though best to put in two lengths of earthed metal conduit (50x50)
The 10mm feed to the 7kW charger is clipped to the batten.

The owner is doing the batten and insulation.
I am concerned about insulation being near my cables and trunking


I presume the trunking it self will be a break in the insulation so could be a thermal bridge?

Could you run the insulation up to the trunking or should they be a gap.

cables clipped along the batten how far should they be from the insulation,
I would like to leave about a 50mm gap? but this will cause this thermal bridge issue I believe?

Also say if  a 2.5mm  socket radial (fused to 16A) was ran through the batten and against the concrete block 
with insulation over it. What installation method would you consider that. I presume these soft concrete blocks have some insulation factor.
Will they be much of a heat sink?

I am concerned about the EV cable really as a continuous load in this stud work. Its has a bit of extra capacity as 10mm2 for a 7kW charger.

How can the wall be adequately insulated, without bridging and the cables be safe?

Thanks

Parents
  • 0

    Thanks vey much for the comments
    I am leaning towards suggesting running an external cable.
    Run 25mm swa  into suitable external enclosures and feed the conductors through the wall
     and into the box and CU. Add a couple of layers of heat shrink on to act as a second layer of insulation and feed into the board?



    Just on the subject of cable in an insulated wall
    Thanks very much. If more stud was added  so as much of the wall was insulated as possible 
    but we has a small section left un insulated. would those cables still be considered in an insulated wall?
    Would that be acceptable?

Reply
  • 0

    Thanks vey much for the comments
    I am leaning towards suggesting running an external cable.
    Run 25mm swa  into suitable external enclosures and feed the conductors through the wall
     and into the box and CU. Add a couple of layers of heat shrink on to act as a second layer of insulation and feed into the board?



    Just on the subject of cable in an insulated wall
    Thanks very much. If more stud was added  so as much of the wall was insulated as possible 
    but we has a small section left un insulated. would those cables still be considered in an insulated wall?
    Would that be acceptable?

Children
  • 0 in reply to JohnE
    JohnE said:
    Run 25mm swa  into suitable external enclosures and feed the conductors through the wall
     and into the box and CU. Add a couple of layers of heat shrink on to act as a second layer of insulation and feed into the board?

    SWA should be properly terminated at both ends, although we have discussed in the past whether a meter cupboard is an enclosure and whether the insulation of the cores is adequate for such a location.

    I really do not think that heat shrink around the cores would give adequate mechanical protection where it goes through the wall, and in any event, how would you terminate the SWA?

    That meter cupboard looks terribly tight, but the original meter was probably significantly smaller and there may have been no isolator.

  • 0 in reply to Chris Pearson

    My thinking was to terminate the SWA in  enclosures, so properly glanded off.
    Then install some plastic conduit through the wall and run the cores of the SWA  through the
    conduit and into the board. A few layers of heat shrink also to act like a sheath?

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