Wiring Induction Hob and Electric Oven

Discussion in 'Electrics UK' started by Eddy555, 26 Aug 2009.

  1. Eddy555

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    I need to wire in a Bosch Induction hob and single oven
    The hob has a max power rating of 7200W
    The oven has a max power rating of 2200W

    I have an older Wylex Type B Consumer Unit with 2 spare 30A connections at present (1 was the old cooker wiring which was disconnected way back when a gas hob/oven was fitted, 1 was the immersion heater (I think) which has just been removed as I've had a combi boiler installed).

    My plan was to run 10mm2 cable from one of these spare fuses to power both the hob and the oven. This should be fairly easy run apart from getting it down a wall as it's all plaster on to blockwork. But I should be able to manage that.

    This 10mm would then run to 2 cooker switches on the wall, with 1 running 10mm to the hob and the other running 2.5mm for the oven. Both would go to cooker connection points behind the oven.

    At the CU I would replace a 30A fuse with one of the modern MCB adapter fittings.
    The max I can find (B&Q, Homebase) is 40A, which seems a bit marginal to me for both appliances from what I've read on the Internet, this forum included.
    Working off 240V the oven will take 9.2A and the hob 30A, so 39.2A max.

    <Questions>
    1) Would I need to try and track down a 45A MCB, or would a better plan be to run the hob over 10mm from a 32A MCB and use the other blank to run a 16A over 6mm to the oven?
    2) There is a ring main next to the current oven point, could I not simply run 2.5mm from this to a switch and then to the oven?
    3) Can someone have a look through my plan and see if there's any thing I may have wrong.
     
  2. ban-all-sheds

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    You can run the oven from a socket or an FCU.

    How big is your Wylex? What is the rating of the main switch? You may not be allowed to have a single circuit in excess of 30A.

    How do you plan to provide RCD protection for the new cables?

    How do you plan to test the new circuits?

    Are you aware that this work is notifiable?
     
  3. Eddy555

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    Thanks for the response.

    There's an FCU already present so I'll use that. Great.

    I think it's got 6 or 7 fuses from memory, it says 60A max on it.

    I was going to fit one of these
    http://www.diynot.com/shop/Wylex_40A_Plug_In_Circuit_Breaker/15122

    I've got an electrician coming on Friday so my plan was to run any new wires back to the CU and then get him to check it out and connect it if he's happy.

    If he did this, would this be all OK with the notification too?
     
  4. ban-all-sheds

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    Then you may not have a device in it rated at more than 30A.

     
  5. Eddy555

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    OK, so the hob should be on it's own feed then. Would the built in 30A fuse be sufficient for it?

    Nope, I've not bought that.

    Um, OK I though the MCB is all that's needed. Why would I need an RCD for the hob?

    Good point, I may well hold off on wiring the hob until I've spoken to him.

    I should be OK to wire in the oven though yes?
     
  6. ban-all-sheds

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    What do the manufacturer's installation instructions say?


    Because the circuit will have concealed cables - I'm assuming they are not more than 50mm deep or provided with mechanical protection?

    IEE Article on 17th Edition requirements for concealed cables.


    Yup - he can sort out the RCD requirements too.


    Yup - Approved Document P says

    The installation of fixed equipment is within
    the scope of Part P, even where the final
    connection is by a 13A plug and socket.
    However, work is notifiable only if it involves
    fixed wiring and the installation of a new
    circuit or the extension of a circuit in a kitchen
    or special location or associated with a
    special installation.


    So as long as you use an existing socket or FCU you'll be fine.
     
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  7. ban-all-sheds

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    You've got gas, and you're choosing to use an electric hob? :eek:
     
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  8. Eddy555

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    The installation instructions aren't very specific about fuses, or very much in general about the electrical installation. More about the location and ventillation.

    I was planning to put a metal shield around the cable run in the wall. I'll confirm with the electrician.

    Induction hobs offer the same controllability as gas, but they're more efficient as it's the pan that heats up, not an electrical element like ceramic or halogen. And it's easier to clean too.

    Thanks again for the advice
     
  9. ban-all-sheds

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    Try and get something in writing from them - I believe that induction hobs don't always (often?) behave in a way which makes the standard diversity calculations applicable.


    Yup - please confirm, as what you planned won't do.


    I'd hate to never be able to use stainless steel, copper, or aluminium pans if that's what I wanted.
     
  10. stunlawless

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    BAS: A bit OTT, but I've got SS pans with a copper layer in the base, and they work perfectly with induction hobs.

    Need to make sure they're compatible before you buy - not all types are.

    Doesn't make my cooking any better though.

    Edit for spelling
     
  11. LiamPope

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    More thermally efficient, yes, but given the relative cost of gas and electricity, most probably not more economically efficient.

    Each to his own though. No problem with ferromagnetic stainless steel pans on induction.
     
  12. Steve

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    Why? Make a pan from one material and then insert a layer of something else. :confused:
     
  13. ColJack

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    copper conducts heat better than the steel, so for a source of heat such as gas where the heat is arround the edge of the pan, it conducts it to the center faster and more evenly than if it was just steel..
    in the common metals, there is only 1 better at condicting heat and that's silver... which would be a bit expensive for a frying pan..
     
  14. ban-all-sheds

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    I wonder how they do that, as they won't get magnetic fields generated in them?

    Isn't most SS cookware made from austenitic steel? Mine is.

    I've also got a set of saucepans made from hard-anodised aluminium, and some ovenware, and I've recently bought a couple of nice frying pans in aluminium with a ceramic non-stick coating.

    All I'm saying is that I'd hate to be restricted in what I could buy because it wouldn't work on my hob...
     
  15. ColJack

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    noo, of course not... because copper doesn't turn magnetism to electricity and visa versa does it ( chough... transformer windings... cough )

    can't beat cast iron for cooking with..
     

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