Wiring of Isolators for kitchen appliances

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Hi,

I'm putting a new ring in kitchen and have read some conflicting advice about how isolators should be wired for under counter appliances, whether they should be wired into 13a switched FCU's or 20a DP switches feeding unswitched sockets. I don't mind which method I use as long it is fit for purpose.

I currently intend to install 3 x 20a DP switches into the new kitchen ring with a spur off each to double unswitched sockets which will power the following;

1. Dishwasher & Washing Machine
2. Fridge Freezer & Microwave
3. Tumbledryer & Gas Hob Ignition

Will any of this cause a problem - some posts say use a 20a DP switch with only a single socket? Is this because 2 13a appliances plugged in could potentially draw 26a through the 20 switch? If so how is this any different to having 2 appliances plugged into a 2-way adapter?

Advice appreciated!
 
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a 20A DP switch is not deisgned to be installed on a 32A ring final circuit in the same way that a fused spur is, unless you can get the manufacturer of said item to warrent this use of it, then you can't use it in such a way

fused spur is the normal way of doing this!
 
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Thanks for reply - what are the 20a DP switches used for then? There are many threads recommending these are used for this application as using a FCU means there are 2 13a fuses on each appliance.
 
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nothing wrong with 20A DP switches on a ring..
as you say however, only use one single socket off each.. for the reasons you said.. a double can draw 26A and will damage the switch...
 
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Thanks, is there really much chance of the appliances I'm using drawing more than 20a?

I'm sure the dryer and hob igniter will be fine, fridge freezer and microwave should be fine, only concern maybe would be the washer and dishwasher on same socket maybe?

please correct me if I'm wrong but how is this any different to having a washer and dryer plugged into a 2-way adapter in a single socket which is only rated at 13a?
 
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as both the washer and dishwasher have heating elements, if used together then there is a posibility of both elements being on at the same time.. this would exceed the 13A rating of the adapter..

without knowing the specifics of the machines it's hard to say exactly what the current would be, but I'd hazard a guess that it's not much under 13A each when heating..
 
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So would I be better off using 13a FCU's to supply the 3 pairs then? I don't really want to have 6 separate isolators around the kitchen for all of the appliances, seems a bit much, i suppose if it's only the washer and dishwasher that are a concern i could split them onto separate single isolated sockets.

Dishwasher max rated at 1.9kw so could pull around 8amp, washer rated at 1.7 - 2.1 kw so another 9amp which suggests this should be OK on the 20amp DP switch?

If I ran a double socket from a 13a FCU the above suggests there'd be a high chance of the fuse going if both appliances on together?
 
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A single socket is rated for a 13A load.
A double socket is NOT rated to 26A or anywhere near it.

2 high load appliances in a double socket will overload the socket.
 
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Slightly off the original subject but does that mean plugging in 2 items such as a kettle (2-3kw) and a toaster (1.5kw) in the same double socket on a ring main would cause a potential problem because I would guess there's a very high proportion of people who do this every single day!
 
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A single socket is rated for a 13A load.
A double socket is NOT rated to 26A or anywhere near it.

MK ones are... says so on their specs.. "13A per socket outlet"

and yes, if you don't want too many switches above counter level, 13A FCU's for each double socket is one option..
another option is grid switches..
these fit 1-2 to a single box and 3-4 in a double box..
so for the same space as an FCU you can have 2 20A DP switches..

you can even get the switches with the names on them.. washer, dish-washer etc..
 
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ColJack - Thanks for all your advice, I will see if I can find the 2 gang grid switches anywhere in the same finish as the sockets I've chosen - are these simply wired as individual 20a units? i.e. ring into first switch, then connected into 2nd switch inside mounting box and then ring back out of 2nd switch with each switch having it's own feed to the socket it is isolating? Presumably need a fairly deep mounting box for all those wires!

Re. using a 13a FCU to feed a double socket for dishwasher/washing machine - the max rating of these appliances suggest they could draw upto around 18amps, does this not rule out the 13a FCU method?

Thanks again for your advice.
 
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yes and yes..
while it would be more than the 13A rating of the fuse, there is the question of whether you will have both items on at the same time, and the odds of the heating cycles being on at the same time
 
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Would it not be possible to do away with the D/P switches and simply pull the ring legs down and install double sockets in the adjacent base units?

Would cut down on cost and get rid of a number of switches on show.

As another small benefit, if in the unlikely event that the fuse in the plug top blows, it could be replaced without having to pull the appliance out.
 
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Yes that would be far easier but I'm doing what most would recommend in having an easily accessible isolator above the counter.

ColJack - Thanks again for all your advice, I like the idea of the 2 gang grid switches but can't seem to find them to exactly match the other sockets etc which have already been chosen so still back to choosing between 13aFCU or 20a DP switches. hmm

Whichever way I go it has to be better than previous (Whole house was on a single 30amp breaker as previous occupier had done this to free up 1-way for a shower! and the circuit very rarely overloaded). Now have new 17th ed CU, separate up/down circuits and kitchen will be on separate ring.
 
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