Consumer unit for Extension

Discussion in 'Electricians' Talk' started by Dereekoo, Jun 10, 2014.

  1. Dereekoo

    Dereekoo Member

    Proposing to have downstairs seperate kitchen dining room extension built and was wondering what happens re the electrics. Existing CU under the stairs 20 plus years old , fuses are push buttons that pop out. What options are open to the sparkies for wiring the new rooms in?? At the moment I am thinking one is to extend the existing ring main/lighting circuits but this will cause problems with sparky certifying due to being plumbed into old circuits???. New CU, but space in cubby hole under stairs very limited to fix a larger CU, therefore CU would have to be fitted somewhere else (kitchen wall, say) and all the circuits that go to current CU extended to new CU, again does this cause problems with cerification and having to extend existing cables (loads of junction boxes??). Is it feasible to have a new CU just serving the extension and powered up with another set of tails from the meter box (or tails spured off the existing tails with some sort of junction box). Obviously there are cost implications with the choosen method and the costs will be whatever but I thought I would get a heads up on whats what before builders start bamboozling with what needs to be done . Thoughts/comments gratefully received
  2. stu1312

    stu1312 Member

    New consumer unit in current location will most likely be the easiest solution. Put a photo up of the location so we can see how tight the space is, there is always options!
  3. unphased

    unphased Screwfix Select

    Some brief thoughts. If I were looking at the job I would be looking to install new circuits for the new-build extension, a 32A ring final circuit for the sockets, a 32A radial circuit for the cooker and a 6A radial circuit for the lights. Options are to add a mini 4-way CU next to existing, or change CU to new. Normally there is sufficient space to do this, wouldn't have thought it necessary to completely relocate it. I would also be looking at the existing earthing and bonding arrangements to make sure they are up to standard and adding or upgrading them as required. I would be looking to avoid altering existing circuits with the mini CU option, but a CU upgrade does require some risk of finding faults on the existing circuits.
    FatHands likes this.
  4. Just to follow on from UP. Presumably you're spending thousands on your extension to give you more space but also to add value to your property. A twenty year old "fuse box" won't have any RCD's so whilst not dangerous is not as safe as it could be. More to the point the absence of RCD's will hamper any electrical alterations you might wish to make in the future. So my advice would be to bite the bullet and put in a new board to current standards and have done with it.
  5. Dereekoo

    Dereekoo Member

  6. unphased

    unphased Screwfix Select

    Nice photographs. :) You can easily fit a new board in that space. The wiring can be tidied up at the same time and it will look great. I echo what NO2GT said.
  7. Dereekoo

    Dereekoo Member

    When you say easily fit a new board do you mean a new CU in the space of the old one or by relocating the stuff srrounding it there will be enough space for a new CU?
  8. wally

    wally Screwfix Select

    I doubt that there is enough space for a dual RCD board not a 15 way standard anyway. The other way to keep size down is to get an enclosure that will fit & then fit RCBOs, this will be a bit more costly but will keep space down to a minimum.
  9. sparky Si-Fi

    sparky Si-Fi Screwfix Select

    RCBO board all the way, Wilts do a 12 way for 119.00 with 8 RCBO's

    You will need another as that 6 way Wylex will take up 6 of the new RCBO's supplied, two spares for the Ring final and the cooker, you might be able to squeeze the lights on the 8th one, but do it properly and get one more, after all its only £18.00 out of the many thousands spent on the build
    Last edited: Jun 11, 2014
  10. sparky Si-Fi

    sparky Si-Fi Screwfix Select

    . . is that a TT install cause I cannot see an earth coming from the cut-out. .?

    If it is, wheres the RCD?
  11. unphased

    unphased Screwfix Select

    Yes. A decent spark will know what to do. The accessories surrounding the old one can be easily relocated and the board could be positioned on the wall, it doesn't need to go back "exactly" in the same position. I agree with Si-fi. I fit RCBO boards as routine now. They beat dual RCD boards hands down.

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