wiring a grid switch

Discussion in 'Electrics UK' started by mulls, 1 May 2007.

  1. mulls

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    Hi,
    Can you advise please.

    I am installing a grid switch with 3x20A switches - one for a dishwasher, one for a washing machine and one for a tumble dryer.

    I have a 13A socket next to the grid switch location witch is on the ring main.

    I am now trying to think of the best way to wire this up. These are my thoughts so far:

    1 Take a spur off the ring main into the grid switch.
    2 Connect the earth cable from the spur to the appliance earth feed cables using the earth terminal on the grid frame.
    3 Connect the neutral cable from the spur via a terminal block in the backbox to the appliance feed cables
    4 connect the line from the spur to each of the 20A switches with the line feed to each of the appliances.

    Each appliance will be protected by a fuse in it's plug as each appliance feed wire will go to a separate socket into which the appliance will be plugged. I'm using 2.5mmsq twin & earth cable throughout.

    IS THIS SAFE AND DOES IT ADHERE TO WIRING REGS?

    Thanks for your replies.
     
  2. davy_owen_88

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    Don't take a spur - extend the ring to the grid switch. 3x 13A appliances connected to an unfused length of 2.5mm² t&e on a 32A circuit isn't a good idea.
     
  3. ColJack

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    i would also fit double pole switches.. that way you break the neutrals too and don't have to put them all in a connector block..

    2x2.5 and 3x1.5 are hard to do into one terminal..
     
  4. sparkybird

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    I have often thought about doing this, but never actually installed one because I believe that the grid switches should be rated at 32A as they are on the ring, and 20A is not sufficient.

    Any others got a view on this?

    SB
     
  5. RF Lighting

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    It is a very well debated subject, and I am yet to hear a definitive answer.

    Personally I do fit the grid switch arrangement, and IMHO the ring in out terminal rating is no worse than that of a 13A FCU, which it is perfectly acceptable to connect to a ring final circuit.


    Does anyone know it the terminals are rated to 20A or if it is just the actual switch contacts?


    Maybe someone should produce a 32A rated grid module to overcome the problem (Although size may be an issue)


    What about installing a contactor panel in a cupbaord, and a nice neat bank of 6A switches above the worktop ;)
     
  6. mulls

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    Thanks all for your replies so far.

    I'd like to extend the ring into the grid as suggested but the cables into the adjoining socket are not long enough to allow this.

    Regarding the switches, I have assumed that the 20A rating would be adequate as they would be required to switch a maximum load of 13A - more than that and the appliance fuse would blow.

    I wish I had the double pole switches though as that would have saved using a terminal block. We live and learn. :rolleyes:

    I suppose that wiring it as originally outlined is not unlike taking a spur to a treble socket - is this permissable and safe?

    Thanks again.
     
  7. securespark

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    Davy said no here!!
     
  8. RF Lighting

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    I really would reccomend returning the switch modules you have, and exchanging them for proper 20A DP kitchen modules.


    It will give you a much better finished job, and it will be easier to use.

    [​IMG]




    [​IMG]
     
  9. davy_owen_88

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    Replace the double socket with 2 singles and your problem is solved. You could also crimp on extensions or replace the cables back to the previous/next socket on the ring.

    A 3 gang socket has an integrated fuse to prevent overloading. If you fit a 13A fused spur before the grid switch you will be limited to 1 appliance at a time, but this would allow you to do what you intend safely.
     
  10. JohnD

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    Sorry your spirit level is broken. Can I send you a new bubble?
     
  11. Steve

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    RF keeps goldfish, he has no shortage of their farts ;) :LOL:
     

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