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Dishwasher and Plinth Heater in same Double Socket ?

Discussion in 'Electrics UK' started by johnny_t, 21 Sep 2016.

  1. johnny_t

    johnny_t

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    I am just in the process of moving things around in my kitchen and am fitting some new units this weekend.

    I currently have a double socket inside one of my units, served by an unfused spur. Not sure what size cable feeds it, but it is a fairly big one (one of the flatter, not particularly flexible ones), and it has had an electric oven plugged into it for as long as I have lived here.

    It would be convenient if I could connect the following into this plug socket (or this spur) instead:

    1 x Dishwasher, rated at 2.2kW (2kW heater, 200W pump)
    1 x 2kW plinth heater

    Question 1 is 'Can I do that just by plugging them in ?'. The dishwasher has a plug on anyway. The instructions with the heater say to put it into a 10A fused spur, but I don't know if that is just them covering themselves or not, and there's nothing really to stop me plugging two 13A 'things' into the existing double socket.

    Question 2, if the answer to Question 1 is No, is what is the simplest / safest way of doing this? If they could be on the same spur, the plinth heater would come after the socket that the dishwasher is going into. Could I, say, replace the double socket with a single socket and then follow that up with an FCU and an extension of the spur to the plinth heater, or is that geting a bit dodgy ?

    Taking the feed for the plinth heater from anywhere else will be a lot of a nuisance so if I can put them both on this it would be handy...
     
  2. sparkwright

    sparkwright

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    I can't remember what the outcome of a long previous discussion about plugging two 13 amp appliances into one double socket was.

    Someone in the past said an MK double socket was rated a 26 amp, rather than 13 amp - but how true that is I don't know.

    There will be many double sockets with two 13 amp loads plugged into it in the world.

    I suspect the plinth heater won't get used much anyway.

    But it is bad practice to plug two heavy loads into one double socket in my opinion, especially if it can be avided.

    Hopefully you will get some helpful advice on this quickly, before this turns into ten or twenty pages of discussion and debate.
     
  3. deadshort

    deadshort

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    Hi, if the socket gets hot, then you will need to have another one fitted for one of the appliances. If i recall i think it was 20a max for an MK socket.

    Regards,

    DS
     
  4. winston1

    winston1

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    A spur can have one socket (single or double) or one FCU. So you can't go with question 2.

    However there is no problem plugging both into a double socket as the total load of 4200 watts is less than 20 amps.
     
  5. johnny_t

    johnny_t

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    Thanks All. Pity that I can have one double socket but not two single sockets, as that would be more convenient, but sounds like I can make this work...
     
  6. John D v2.0

    John D v2.0

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    Personally I'd say put them both on FCUs, or if the wire is clipped direct or plastered into the wall, put the heater on one FCU and a separate FCU to a socket for the dishwasher in case you want to unplug it. It still complies as you only need short circuit protection which should still be fine unless your cables are really long. Not using a 13a plug on a heavy load can only be a good thing.

    Edit: this also assumes the flat grey cable is 2.5mm2, but it should be.

    Edit again: or you could do your option 2, but put a 20A MCB at the start of the spur. But now you're getting into silly land.
     
  7. winston1

    winston1

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    Why on earth would you put the dishwasher socket on an FCU? A socket does not need an FCU. The connected plug already has a fuse.
     
  8. John D v2.0

    John D v2.0

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    No need to be rude, the answer is because a socket and an fcu aren't permitted by the regs, only a single or double socket. However if you can provide overload protection somehow else then you can prove it's OK.
    I'm fact if you put in an fcu, you can daisy chain as many sockets as you like in 2.5. But in the OPs case he needs more than one 13fcu for his load, and he only needs one further socket.
     
  9. securespark

    securespark

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    You can have two singles. But you need to put a 13A fused connection unit in the feed to those sockets to limit the load drawn.

    If you ever get to the point where the two appliances are drawing more than 13A between them, the fuse in the FCU will blow.
     
  10. winston1

    winston1

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    But you have a socket for the plinth heater and an FCU ( feeding a socket for dishwasher) so not permitted.
     
  11. John D v2.0

    John D v2.0

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    It isn't permitted as a standard circuit, but you can also design your own circuits to BS7671.

    In this case, 2.5mm t&e is clipped direct is good for 27a, so you can can connect 2 13a fused circuits to it even if they are to be fully loaded.
    You would have to make sure voltage drop and loop impedance, and consider where on the ring the spur is from, but let's not drown the OP in rules for the sake of it.
     
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  12. EFLImpudence

    EFLImpudence

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    I agree with you - but BS7671 does say only one socket, beit a single or double.

    It doesn't make sense but there it is.
     
  13. JohnW2

    JohnW2

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    To be precise, an 'inforrmative Appendix' (i.e. 'guidance', not regulation) of BS7671 says that.

    Kind Regards, John
     
  14. EFLImpudence

    EFLImpudence

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    I thought you corrected me when I said that once, by quoting a regulation where it actually says only one accessory.
     
  15. EFLImpudence

    EFLImpudence

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    If that's not the case then I would have no qualms about fitting two single sockets.
     
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