2 x single cookers and 1 x induction

Discussion in 'Electricians' Talk' started by JJ1976, Aug 25, 2015.

  1. JJ1976

    JJ1976 New Member

    Hi all,

    Been trying to get some info on what wiring/mcb/switching i will need for my kitchen install but there is SOOO much conflicting info.

    What i will be having is...

    2 x Neff single ovens (3kw)
    1 x Neff induction hob (7kw)

    Currently i have a 6mm cable running from a 36A MCB that runs a cooker with separate grill/lower small oven. The gas hob has a feed from the 13A ring to "click click" ignite.

    My consumer unit has no spare spaces.

    I already have a roll of 10mm cable so was thinking.....

    40A MCB (single pole or dual??)
    10mm cable to 45A cooker switch/isolator (for all 3 units)
    10mm cable to cooker junction box
    6mm cable to hob
    2 x 2.5mm cables to 2 x 13A fused socket/plug?

    Please help :)

    (don't shout too much - haha)

    JJ
     
  2. KIAB

    KIAB Super Member

  3. JJ1976

    JJ1976 New Member

    yeah - that was what i was envisaging (only better) - thanks

    how does the rest of my "thinking" add up? Some posts i have seen seem to state that 6mm and 32A MCB would work with this total KW (taking into account diversity)

    JJ
     
    Last edited: Aug 25, 2015
  4. Coloumb

    Coloumb Screwfix Select

    Would a 40a mcb clear a fault on 2.5mm? Adiabtic required...
     
  5. JJ1976

    JJ1976 New Member

    ??? don't know what that means - sorry

    JJ
     
  6. sparky Si-Fi

    sparky Si-Fi Screwfix Select

    You have answered your own Q. get a spark in, running in new circuits is under building regs and needs EIC for compliance
     
  7. sparky Si-Fi

    sparky Si-Fi Screwfix Select

    What i will be having is...

    2 x Neff single ovens (3kw)
    1 x Neff induction hob (7kw)

    All the sparks on here can calc this current demand using diversity and know exactly the answer.

    Currently i have a 6mm cable running from a 36A* (*<------???) MCB that runs a cooker with separate grill/lower small oven. The gas hob has a feed from the 13A ring to "click click" ignite.

    My consumer unit has no spare spaces.

    I already have a roll of 10mm cable so was thinking.....

    40A MCB (single pole or dual??) No such thing as a dual pole SP type B breaker for a domestic install

    10mm cable to 45A cooker switch/isolator (for all 3 units) good luck with cramming 6 10mills in that switch plate without damage and strain on the front cover

    10mm cable to cooker junction box Where is this to be located for inspection may I ask?

    6mm cable to hob

    2 x 2.5mm cables to 2 x 13A fused socket/plug?

    Were now stepping down CSA of cable with no change to overcurrent protection

    Please help :)

    certainly, get a spark in your a little out your depth mate. . .bad design and I could not install this design and give all the relevant forms and legal issues (which is what this job entails)
    (don't shout too much - haha)

    JJ[/QUOTE]
     
  8. JJ1976

    JJ1976 New Member

    I can calculate diversity no problem - what I don't know is if diversity truly applies to 3 separate units.

    E.g. I know a 13kw range cooker with a single feed only requires 6mm.

    I'm going to get an electrician in but I need to cut away the ceiling in the utility room to feed a new cable through into the kitchen which requires some prior planning. And ordering of items such as a new mcb for my consumer unit - hence asking.

    Sorry if unrolling some wire and feeding it into another room is only for the specially trained :(

    JJ
     
  9. sparky Si-Fi

    sparky Si-Fi Screwfix Select

    Sorry if unrolling some wire and feeding it into another room is only for the specially trained

    Its a new circuit and requires certification and LABC, its daft I know but telling you as it is. .
     
  10. JJ1976

    JJ1976 New Member

    Hi - thanks and yeah I know. My father in law is an ex electrician and he will get his pals in to certify.

    (This is what we did for the feed to the hot tub)

    What would be your suggested install?

    JJ
     
  11. sparky Si-Fi

    sparky Si-Fi Screwfix Select

    "My father in law is an ex electrician and he will get his pals in to certify."

    Needs to be registered with a self certification Scheme (NICEIC or NAPIT) . .is he? :rolleyes:
     
  12. Coloumb

    Coloumb Screwfix Select

    If your father in law is registerd and signing off your work then that's illegal.
     
    sparky Si-Fi likes this.
  13. JJ1976

    JJ1976 New Member

    we are just running a cable from 1 room to another and not connecting - i'm just trying to work out what bits i need to get or if i need take down half my utility ceiling

    so diversity

    7+3+3 = 13KW
    13000/230 = 56.5A

    Diversity : 10A + 17A (30% of 56.5A) = 27A

    6mm and 32A should be ok (and rated to 35A on domestic?)

    but it that applicable to 3 separate ovens/hob??

    JJ
     
  14. Coloumb

    Coloumb Screwfix Select

    Siffy has already answered your q. It's a very poor design and I don't think it will work even with deversity applied. If you have a spare way you would be better off running an swa submain to a new cu in the kitchen and running your three ovens off of seperate breakers from the new cu. You will also need rcd protection and local isolation for the cooking kit.
     
  15. Coloumb

    Coloumb Screwfix Select

    And take account of discrimination
     
  16. JJ1976

    JJ1976 New Member

    That was my other option

    Although 2nd consumer unit on the adjoining wall of the utility.

    But then still require a 10mm feed to it if diversity doesn't apply?

    JJ
     
  17. Coloumb

    Coloumb Screwfix Select

    Mate we can't design this whole thing for you as none of us have actually had any visibility of your problem. You need to get a spark in to sort this out properly as you are clearly out of your depth (we aint talking adding an extra socket or light fitting). If you want to do some of the cable runs yourself to "save" money (you won't anyway) then you will need to explain this to the spark who does the work. They may, or may not be happy with this.
     
  18. PaulBlackpool

    PaulBlackpool Screwfix Select

    If your father in law is an ex-electrician won't he know what to do albeit illegally?
     
  19. JJ1976

    JJ1976 New Member

    I've looked all over this community in the past weeks and the confusion and arguments between electricians over fitting cookers doesn't build confidence.

    I've seen the 10mm vs 6mm inc diversity arguments here, IET and many other forums as well as the "my sparky has said this" followed by the "he's wrong" and "you sure he's a sparky?".

    I thought I would ask what is suitable as I thought it would a simple answer but it's already getting chaotic.

    Why does an electrician need to see a room to work this out?

    The ovens and hobs won't be in there until after he has done the wiring anyway.

    I have a 13kw draw over 3 appliances
    I have 6mm cable
    I have a CU
    It's uk voltage
    It's about a 5m run

    What do I need to change?

    ....I know I know..... Pay for a sparky.


    Damn my engineering brain wanting to know what to do first.

    JJ
     
  20. Coloumb

    Coloumb Screwfix Select

    I have no problem that with time and experience you could do the work but right now you don't. Experience can't just be picked up and chucked about like a football, it has to be learned the hard way. So if you don't have it you have to pay someone who has.

    All of the sparks here have done - with a job this big isn't something any of us could just say "right do this, this and this", it would need to be properly looked at.
     

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