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Quick check on cable size

Discussion in 'Electrics UK' started by RickH, 28 Aug 2019.

  1. RickH

    RickH

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    Running in a T&E cable for an oven only (no hob)
    This is rated as 5.9KW ..... so therefore 26A

    Quick look up for a clipped direct (method C) cable on a 3m run shows that 4mm2 is more than beefy enough at 37A

    That all correct ?
     
  2. flameport

    flameport

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    Yes, provided it's a 32A circuit breaker.
     
  3. RickH

    RickH

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    Might have to re-think this a bit.
    There is a radial cct out to an MK Grid switch which is rated at 20A, this is in 4mm2 running from a 20A breaker. form the switch 4mm2 cable to a wiring connection point.
    Previous oven was always hapy on the 20A breaker.

    As Max capacity of this is 26A .... I need to find a solution for this Grid switch.
     
  4. AndyPRK

    AndyPRK

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    there is a youtube video on this coming soon!

    Fitting a contactor near the consumer unit to switch the oven (or hob) on and off. Clunk!

    Personally I consider it a crazy situation, just so a grid switch can be used!
     
  5. RickH

    RickH

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    I can't find a Grid switch higher than 20A ..... I know I could increase breaker to 32A ... but would then need higher capacity grid switch
    Anybody any suggestions ?

    So far only thought is I would need to put a link in bypassing the GRID switch (and fit a blanking plate) and put a DP cooker switch instead of MK5045 connection point.
    Unless anyone else has a better idea.


    If my idea is the option what in neatest way to 'bridge' the 4mm t&e ... use WAGO connectors ...
    https://www.tlc-direct.co.uk/Products/WA412C.html They are good for 32A
    or WAGO push connectors rated at 40A
    https://www.tlc-direct.co.uk/Products/WA173.html


    Anybody experience of using these ? which is easiest to use ... or is there a better way

    Connection will be within confines of the 'back box' so all still protected.
     
    Last edited: 28 Aug 2019
  6. RickH

    RickH

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    OK .. thanks, always thought DP local switch was requirement ... maybe as you see so many cooker switch boxes.
     
  7. flameport

    flameport

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  8. RickH

    RickH

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    Unfortunately that would not be compatible with MK Grid system
     
  9. sparkwright

    sparkwright

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    What else does the grid switch serve?

    Are you not running a new separate supply for the oven then?
     
  10. RickH

    RickH

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    No exisiting 4mm2 cable is big enough
     
  11. AndyPRK

    AndyPRK

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    watch from 4 minutes

     
  12. sparkwright

    sparkwright

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    What else does the grid switch serve??
     
  13. Taylortwocities

    Taylortwocities

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    Hmm. Quite a few cables zig zagging in that stud wall. May be >50mm deep though, but doesn’t look kosher to moi.
     
  14. daggermark

    daggermark

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    That was exactly my thought. I'm not convinced they are deep enough, and they certainly aren't in safe zones.
     
  15. eveares

    eveares

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    My issue with using a contactor with a remote switch without also using a standard DP isolator is what happens if the contactor gets jammed on. Note that you would not use a domestic DP switch for safe isolation either as you can not lock them off normally.
     
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