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Converting to a 16A cooker switch?

Discussion in 'Electrics UK' started by bobthedob, 26 Apr 2018.

  1. bobthedob

    bobthedob

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    Currently I have a 13A cooker connected to a 13A plug and socket in an island in the kitchen.
    It was installed about 18 years ago.

    The cooker needs replacing and everything is 16A these days, even for a 3kW oven :(

    The existing 13A socket in the island is a single radial circuit with nothing else on it, and its own 16A MCB in the fuse box.
    (eg; 16A MCB --> a pair of standard 2.5mm2 cables --> a single 13A socket)

    Can I replace the 13A socket with a 16A cooker switch?
    The 16A MCB is fine, and the pair of 2.5mm2 should be fine as well?

    I can then hardwire the replacement cooker to the 16A cooker switch.
    Thanks
     
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  3. Taylortwocities

    Taylortwocities

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    Yes. Remove the socket and replace it with a 20amp DP switch. Like this

    [​IMG]
     
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  4. bobthedob

    bobthedob

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    Thanks for the quick reply. Should I connect the pair of cables or only one should be sufficient in this case?
    eg; 16A MCB -> single 2.5mm2 -> Nice 20A DP switch as shown above
     
  5. Taylortwocities

    Taylortwocities

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    Unusual for there to be two cables in a radial, unless it goes on to somewhere else as well as the oven.
    Are there two conductors in the top of the 16A MCB? Are you sure the circuit goes nowhere else?
    Maybe a socket in the island?
     
  6. bobthedob

    bobthedob

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    Good point. I will double check that back at the fuse box.
     
  7. ban-all-sheds

    ban-all-sheds

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    How does 3000/230=16?
     
  8. bobthedob

    bobthedob

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    Doh. Bad news.
    Its actually on the damned kitchen ring circuit.
    Somewhere the pair must come out at a double socket on the ring main - I will have to go around the sockets to find with one.
    I'm screwed :(

    I guess I could find where the pair from the island come out on one of the wall sockets, and then look to put in a new circuit from the fuse box to that point.
    That would save me going under the stone floor.
     
  9. Taylortwocities

    Taylortwocities

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    That would mean a new circuit, which is a notifiable job.
    When a ring is installed, one cable will come from a socket on the kitchen ring and the second cable will go on to a different socket. It is possible that both cables appear at the same place, but I doubt it.

    Maybe its worth looking at your oven requirements. As BAS has pointed out
    A 3KW oven is 13amps. And the actual running current will be less dure to thermostat control.
    What is the make and model of oven that you have in mind. You may be OK to just pop a plug on it and carry on as before.*

    *This will depend on the oven and also what else is on the kitchen ring: do you have high current items on there too?
     
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  11. bobthedob

    bobthedob

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    Completely agree with you - probably some damned EU regulation :)
    All cookers and ovens specify a minimum of "16A hard wired" even for these lower amps - as Steve Wright would say "its the law"

    Pain in the backside
     
  12. bobthedob

    bobthedob

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    Yes I agree with you, but the stone floor and water-based underfloor heating make me think they will have gone for easiest shortest route? If I am lucky.
    I have checked a few sockets and they all feed down from the ceiling (as you would expect) I will keep going until I find some sockets feeding from the floor.
     
  13. bobthedob

    bobthedob

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    Yeah! Found them. Going to a pair of double sockets as you predicted.

    Now, anyone got any bright ideas on what to do next?
    (Apart from running a new cable from the fuse box??)
     
  14. bobthedob

    bobthedob

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    It gets worse. I have been onto the manufacturers website and they rate it officially at 3.5kW :(
    Hence the 16A in this case.

    So I have to get a sparky in to put in a new circuit for the 16A, or I look around for a strictly specified 3kW.
     
  15. JohnW2

    JohnW2

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    There is a concept of 'diversity' which allows one to consider a cooking appliance as drawing less current than its 'maximum power' would suggest, which takes into account the fact that the average power drawn by a cooking appliance will never be equal to the maximum for any appreciable length of time.

    If that 3.5W was quoted at 230V, application of diversity would allow you to treat it as about 11.6A. If the power is quotes at 240V, you could treat it as about 11.2A. In both cases less than 13A.

    I think the '16A' thing arises because in most of the EU, 16A circuits are what they mainly have (and the same appliances are sold throughoput the EU).

    Kind Regards, John
     
  16. bobthedob

    bobthedob

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    Hi John, I do like your thinking.
    I will google this diversity thing some more :)
    Thanks
     
  17. JohnW2

    JohnW2

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    The standard accepted diversity calculation for cooking appliances is very simple ...

    ... to get the after-diversity current you simply add together 'the first 10A' and 30% of the remainder (above 10A).

    As an example, if the maximum ('rated') current were, say, 15A the after-diversity current would be 10 + (5A x 0.3), namely 11.5A, the 5A being 15 minus 10. Similarly, if the maximum current were, say, 25A, the after-diversity current would be 10 + (15 x 0.3), namely 14.5A.

    Happy Googling!

    Kind Regards, John
     
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