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New oven and hob

Discussion in 'Electrics UK' started by Crakkers, 8 Oct 2019.

  1. Crakkers

    Crakkers

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    Looks like I will be having a new double oven and an induction hob.

    Both are likely to be 32 amp.

    I currently have one 32 amp mcb in the consumer unit that feeds the existing cooker. This should be fine for the new oven, but what about the hob? I know I could get a 13amp hob, but most are 32 amp.

    My consumer unit has no extra space in it.

    What are my options and likely costs?

    Thanks in advance.

    C.
     
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  3. Simon35

    Simon35

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    What's the combined kW rating of both items? Very likely that both will be perfectly fine connected to your existing 32A supply.
     
  4. sparkwright

    sparkwright

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    Or you may be able to rearrange your consumer unit to get two spare ways.
     
  5. Taylortwocities

    Taylortwocities

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    They won’t be. As above, tell us the power (kW) requirement for each one and we can advise further.
     
  6. Crakkers

    Crakkers

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    We have yet to choose the oven and hob.

    We are aware of 13 amp plug hobs, but also been told that they are not that powerful.

    A quick scan of the market shows that i could buy an oven with a rating of 5.9KW and hob at 7.2KW. It surprises me that the rating of the oven is less than the hob, but anyway.

    So if that was the case, where do i stand with current consumer unit?
     
  7. Crakkers

    Crakkers

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    Just done a few calcs....

    If supply is 240V and max MCB is 32A, then max wattage of oven and hob would be 7.6KW, which means the above will cause an overload????
     
  8. EFLImpudence

    EFLImpudence

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    You can connect up to 15kW to the existing circuit because cooking appliances do not draw the full current all at once.
     
  9. Crakkers

    Crakkers

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    I'm now finding internet pages that tell me that a standard cooker installation with a 32A mcb / fuse can cope with 15KW?

    Can anyone explain?
     
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  11. EFLImpudence

    EFLImpudence

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    I just beat you to it.
     
  12. Crakkers

    Crakkers

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    Why do they not? Is it as simple as you dont have everything on at once? (all 4 hob rings, plus oven plus grill) But what if you do? Christmas day?
     
  13. EFLImpudence

    EFLImpudence

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    ...because even when 'on' they cycle on and off all the time - more off than on.

     
  14. Crakkers

    Crakkers

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    So, so long as the hob and cooker are less than 15KW, I'm good to go with current installation?
     
  15. EFLImpudence

    EFLImpudence

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    Yes, assuming it has been installed correctly.
     
  16. Harry Bloomfield

    Harry Bloomfield

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    Its called 'diversity', despite them all being turned on, they will not all be drawing current at the same time, or all drawing full current. Imagine that amount of heat in the enclosed space of a domestic kitchen. Normally, you switch one or two items on at a time, those items get up to temperature and begin switching on and off as you switch more things on, which likewise switch on and off as they are just required to maintain their set temperature. Any incidence of overload, will be of a short duration and quite rare.

    'Diversity' means your cut out fuse can be rated less than the current draw if everything in your home is switched on, because it never will have everything turned on at once. 'Diversity' calculations are conducted for the main cable buried in your street and the grid, because not every home and business will be drawing maximum current at the same time.
     
  17. Taylortwocities

    Taylortwocities

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    Just add up all the MCB values on your consumer unit. What do you get, around 240amps for mine.
    yet the maximum main fuse is 100amps. Why doesn’t blow all the time?

    Why don’t we need a new power station every time a few new houses are built?.

    How much do you recon the distribution companies allow for each house?
    100amps, nah
    50 amps, nah
    Much much less. It all uses the diversity principles.
     
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