Consumer Unit Layout - Information only

Discussion in 'Electricians' Talk' started by mackie, Aug 8, 2018.

  1. mackie

    mackie Member

    Hi all.

    I am after some advice just to allow my planning of a new CU to replace the current setup I have.

    I know the possible comments that could come about getting a qualified sparkie in, the issue is my go to man is currently on holiday for the next 2.5 weeks and I want to get some planning in place.

    I am knocking two rooms into one and building regs have to be considered so I cannot do the work myself anyway as itwill have to be certificated etc. I am only after information to satisfy my brain.

    So if you can give me any guidance I am after is how I can combine the following two CU's into a one new CU. I already have a new 21 way Metal Clad unit with a 63a and 80a RCD.

    Consumer Unit 1
    • Running direct off main switch
    1. Boiler - 16a MCD
    2. Water Heater - 16a MCB
    3. Lights Up - 6a MCB
    4. Lights Down - 6a MCB
    5. Cooker - 32a MCB
    • Running off 63a RCD
    1. Shower - 45a MCB
    2. Sockets Kitchen - 32a MCB
    3. Sockets Ring - 32a MCB
    4. Pond - 16a MCB
    Consumer Unit 2
    • Running off 40a RCD
    1. Sheds - 32a MCB
    2. Rear Outdoor Socket - 16a MCB
    3. Electric Car Charger - 32a MCB
    As I say my go to man is away and, yes I could wait until he comes back, I just wanted to understand the layout that would be best.
     
  2. Coloumb

    Coloumb Screwfix Select

    Why do you want to combine them? Looks like a good setup to me as it is, and I would guess that at moment both a fed directly from the c.o. via a henly block or some such arrangement so it may not be possible to combine them. How about a few pics?

    Not withstanding you spark going on holiday, I should add.:rolleyes:
     
  3. mackie

    mackie Member

    Hi, I have to move them for a couple of reasons.

    1) Building Regs said I had to change the CU to Metal Clad.
    2) Old room was not finished and needs plastering.
    3 IMG_0172.JPG ) They look **** (not shot)
     
  4. Coloumb

    Coloumb Screwfix Select

    You don't need to change the cu because of building regs, who told you that?
     
    Bazza-spark and seneca like this.
  5. seneca

    seneca Screwfix Select

    Agreed Col!
     
    Bazza-spark likes this.
  6. DaveF

    DaveF Active Member

    The only thing I would do is move the pond to share the rear outdoor socket so a failing pond pump doesn't trigger switch something important, like dinner, but honestly apart from that you are better sticking with the arrangement there already. The new box will have two RCD's and I would keep or renew the outdoor box for simplicity and convenience. I mean you don't have to, you can simplify it a little, but it's good as it stands. Why fix what ain't broke?
     
  7. seneca

    seneca Screwfix Select

    When I pull out of my scam membership later in the year I can see i'll be doing a lot of "alterations and additions to existing circuits" ;)
     
  8. sparkykent

    sparkykent New Member

    Don't worry about building control,take the advice from strangers on the internet
     
  9. Pollowick

    Pollowick Screwfix Select

    Ask building regs/control what regulation requires a metal clad CU. Get them to put it in writing and I am sure they will not.


    IF you do change then think about asking your electrician to use RCDs for most circuits but to use individual RCBOs for the Pond, Sheds, Outside socket, Car Charger and Lights. They are ones which are more likely to be tripped due to an accident, or in te case of light, they will not go off when something else trips.
     
  10. Mr A greig

    Mr A greig Member

    If you want to change your consumer unit the new one must be metal.
    I think your bathroom lights may need RCD if you are upgrading but I could be wrong.
    For the rest I would go as follows
    Direct off main. Lights
    Rcbo shower
    Rcd1 boiler, heater, sockets
    Rcd2 kitchen sockets, cooker
    Rcd3 shed, outdoor socket, pond, car
    I'm no expert just preference. Reasons are if the shower trips an RCD you want to know about it. RCD 1 is unlikely to trip and has things you don't want turning off on you. RCD 2 is more likely and is limited to a fault in the kitchen and 3 is most likely and least essential.
    Unless off course having your car charged is essential in which case put it separate.
     
  11. Sparkielev

    Sparkielev Screwfix Select

    It would be good to put a metalclad consumer unit in with nice fancy rcbos but you don't have to, are BC going to knock on your in January when the new amendments activate and tell you to comp!y no they wont, me personally I would fit a metalclad with rcbos where most applicable
     
  12. mackie

    mackie Member

    Can remember now if building reg guy said it could or should be changed (it has been a two year project already to take out the wall, so I keep being reminded by the better half). As before though I defo needed to move it because of the wall needing plastering etc and maybe it is me with spending all this money to do the room to be left with a crappy looking cu (even if it will be inside a cupboard). It also gives me the opportunity to move the box to the left so it frees up more of the wall.

    My hug is back in a few weeks, I can wait until then to discuss more with him.

    All advice / views appreciated as always.
     
  13. Peter208

    Peter208 Active Member

    Can I ask, why is metal clad cu the new requirement?
     
  14. Mr A greig

    Mr A greig Member

    Fire proof rating afaik
     
  15. Mr A greig

    Mr A greig Member

  16. Magicspark

    Magicspark Active Member

    If I was moving the boards I would also get rid of what you’ve got and replace it with a new board. The best option would be RCBOs for all of the circuits. 2nd best would be a split load board and put selected circuits on rcbos and the rest on the RCD. 3rd a high integrity board, split the circuits across the two RCDS and a selected few on rcbos on the main switch side. Finally would be to use a dual RCD board and split all of the circuits across both RCD’s.

    In terms of layout you are looking at minimising disruption in the event of a fault. To achieve this obviously the best option is individual RCBO’s. If the budget doesn’t permit and you went for a dual RCD board, it would be best to arrange the circuits across the RCD’s so that in the event of a fault you don’t loose lighting and power in the same place at the same time. You could achieve this by putting up stairs lighting and down stairs sockets on one of the RCD’s and down stairs lighting and upstairs sockets on the other RCD. If you have say two ligting circuits or two sockets circuit that serves the same floor then it would be wise to also split these across the two RCD’s. for example down stairs sockets on one RCD and kitchen sockets on the other RCD.
     
  17. Magicspark

    Magicspark Active Member

  18. Pollowick

    Pollowick Screwfix Select

  19. Peter208

    Peter208 Active Member

    Thanks to all for the info regarding the Need or No need to have a MC CU
    London Fire Brigade have seen an increase in fires started in the CU, it's this that has changed the regs.
    Shame that the meter readers who take a reading once or twice per year can't also carry out an inspection of the CU.
     
    Mr A greig likes this.
  20. Mr A greig

    Mr A greig Member

    Yeah ok it doesn't have to be but probably going to be though as that's all anywhere sells apart from eBay. I mean you could if you really wanted to prove a point carve one out of stone or perhaps a blown glass consumer unit? But as far as going to the shops for a consumer unit it's going to have to be metal.
     

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