New Workshop Electrics

Discussion in 'Electricians' Talk' started by TopHatTaylor, Apr 15, 2020.

  1. TopHatTaylor

    TopHatTaylor New Member

    I'm currently building a workshop at the end of my garden and just planning my electrics. I will be getting an electrician in to do most of the work but wanted to understand what my best option would be.

    The workshop is about 40m from my existing consumer unit thats located in my garage. I'm planning to dig a trench to lay a 2 core SWA cable from my existing consumer unit up to a new consumer unit in the workshop. I'm wasn't planning on bringing the earth up but adding new earth rod(s) by the workshop itself.

    I was thinking of putting in a 10-Way consumer unit in the workshop as gonna be running a fair bit of kit up there ( heaters, welder, table saws etc) but wondered it this should be fed straight form the existing consumer unit or would it be better to split the tails before the existing consumer unit at the garage and keep the two consumer units separate? Thats been done before as I have an electric vehicle charge and thats how that was done.

    Any advice or your thoughts would be great.

    Heres a pic of my existing Consumer Unit and meter etc...
  2. Sparkielev

    Sparkielev Screwfix Select

    Switch fuse is the way to go, 40m is a long way we really need the full loading of what's going in the workshop, but 10mm swa would be a minimum requirement, also that service head looks dated and at a guess looks like a fused neutral, your sparkie should really advise this isn't a DIY job and needs notifying
  3. TopHatTaylor

    TopHatTaylor New Member

    Maybe I wasn’t clear, I’ll be digging the trench and that’s about it. I can’t get anyone in at the moment because of lockdown so thought I would ask the community what they would suggest.

    Can you clarify what you mean by a switch fuse?
  4. Bazza

    Bazza Screwfix Select

  5. Jitender

    Jitender Screwfix Select

    I saw one isolator at work supplying 3 individual boards and each fused seperatley.

    Some welders need a 32A supply.

    Nice peoject if designed carefully.

    Would 3 phase be a possibilty. Depending on the machinery you will gave.

    Not an electrian but intrested in the design side.
  6. Comlec

    Comlec Screwfix Select

  7. TopHatTaylor

    TopHatTaylor New Member

  8. TopHatTaylor

    TopHatTaylor New Member

    No chance of 3 phase and would be way over the top I think anyway. It’s going to be more DIY level tools but want to get it all right and effectively future proof it.
  9. Jitender

    Jitender Screwfix Select

    Maybe instead of one isolator, you could get a TP+N isolator/ 3 pole switch fuse.?

    So it combines 3 fuses.

    For instance:

    EV Charger = 60A
    House Electrics = 100A
    Workshop = 60-80A

    Some of the electricians could advise if this is the correct setup.

    How many ways are there on your tails connectors. The Lucy ones hav 5 ways so possible to supply 4 boards off it.
  10. Bazza

    Bazza Screwfix Select

    If you wanted to isolate the feed to the workshop, you operate the switch and the house goes off as well.
    I don’t think that’s a good plan.
  11. Jitender

    Jitender Screwfix Select

    Good point, didn't think of that:)
  12. TopHatTaylor

    TopHatTaylor New Member

    OK that sounds interesting, so you mean replace those black splitter boxes (Henley block?) with something like this

    Or should the blocks stay and just take a new feed from the block (if they have room) and take this into a switch fuse and then feed the workshop CU from that?
  13. Jitender

    Jitender Screwfix Select

    Being a bit thick but could the op go for a 6 way consumer unit and then load with 3 individual DP isolators according to the demand?

    Installation could benefit from a main isolator and could have been done when the EV unit was installed.

    That way the OP can isolate each of the three separate circuit individually.
  14. Jitender

    Jitender Screwfix Select

    No that won't work as would isolate the whole supply as Bazza mentions, what you're after is independent isolation for each of the 3 boards (see previous post). And would tidy up the installation.
  15. TopHatTaylor

    TopHatTaylor New Member

    Yeah that makes sense, so ideally I should be able to isolate the supply to my two additional supplies (EV and Workshop) and potentially my house CU. At least this arms me with some information for when I can get an electrician in :)
  16. Jitender

    Jitender Screwfix Select

    May be something on the market or do the metal enclosure with 3 individual DP isolators if electrician confirms good plan.
  17. TopHatTaylor

    TopHatTaylor New Member

    Another question would be if it would be spending a little extra money and adding in CU with surge protection along with RCBOs, would that cause any issues ?
  18. Jitender

    Jitender Screwfix Select

    Not too sure anything exists, will wait to see what others say.
  19. Jitender

    Jitender Screwfix Select

    This is what they had at work.


    Although not what your after it where I'm getting my logic.

    Do you know what the main fuse is in supply.

    When you get electrician see if it possible to have one main isolator to switch off the whole installation. And 3 separate one for each of the board.

    Switch fuse as posted before is the easiest method. with a DP incomer after the meter to switch off the whole installation.

    In meantime you could compile a list of all the circuits you would need i.e welder some will need a 32A supply etc.
  20. Sparkielev

    Sparkielev Screwfix Select

    Think your over complicating things, you need a switch fuse coming off a Henley block to your workshop, adding aconsumer unit shouldn't make any difference in fact RCBOs is the way forward

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