Fitting 2 20 amp appliance switches help wanted

[LeeUK]

Hi

Prior to tiling! I'm currently chiselling space for a couple of 20a switches.

I'm unsure which switches to go for, seems a lot of space for 2 switches so....

Can i use these grid switch type instead in one box?
seems obvious but first time in 20 years DIYing i've had to do this

Also, the switches will feed a socket for the appliance
as each switch feeds one socket, can I get a double socket that can be switched by each of the grid switches in stead of 2 individual sockets?

 

[JohnW2]

Can i use these grid switch type instead in one box?
seems obvious but first time in 20 years DIYing i've had to do this

Yes.

Also, the switches will feed a socket for the appliance as each switch feeds one socket, can I get a double socket that can be switched by each of the grid switches in stead of 2 individual sockets?

Not that I am aware of, but you can get 'dual' (as distinct from 'double') back boxes which would allow you to install two single sockets side-by-side.

Kind Regards, John

 

[rsgaz]

Not that I am aware of

You could knock one up from two euro modules and a double gang faceplate...

https://www.edwardes.co.uk/en/produ...uro-50x50mm-13amp-240volt-socket-module-white

Might need to put a dual supply warning sticker above it though!

Gaz

 

[JohnW2]

You could knock one up from two euro modules and a double gang faceplate...

Indeed so - that would be another option.

Might need to put a dual supply warning sticker above it though!

Interesting point, although it's not the sort of context in which such stickers are usually used. I'm sure that there are countless grid switch setups, not to mention 2-gang and 3-gang light switches, which are supplied by two or more circuits (let alone two different switches from the same circuit, as in what we are considering) - but I don't think that I have ever seen a warning sticker on such things!

Kind Regards, John

 

[Echo the husky]

I'd go for a dual box and 2 single unswitched sockets. The Euro socket modules I've come across always seem to be of poor quality.

 

[LeeUK]

cheers, dual box it is

heres one -
I'm branching off a double socket to the grid switches
Can I use 2.5mm 2 core earth and single live from the double socket, sharing the neutral / earth or must I use 2.5mm twin / earth for both switches?

 

[EFLImpudence]

I'm branching off a double socket to the grid switches
Can I use 2.5mm 2 core earth and single live from the double socket, sharing the neutral / earth or must I use 2.5mm twin / earth for both switches?

Not sure I understood that.

For two single sockets -
it depends how you read the regulations - others may disagree.
One 2.5mm² T&E from socket to first switch and then on to second - sharing all three - would electrically be sound.

If you had more than two sockets then you should use 4mm².

 

[JohnW2]

I'm branching off a double socket to the grid switches ... Can I use 2.5mm 2 core earth and single live from the double socket, sharing the neutral / earth or must I use 2.5mm twin / earth for both switches?

That poses all sorts of questions, particularly relating to the nature of the circuit that you are 'branching off'. If it is a ring circuit, protected by a 32A breaker or 30A fuse, then you would certainly have to have separate cables, and if the 'source socket' was itself a branch ('spur') off the ring circuit (rather than being part of the ring), then you could not do what you are proposing at all. If the circuit is protected by a 20A MCB/fuse, then things would be different, and you probably could take a single cable from the source to your two new switches (and sockets).

So, the main question is - what do you know about the double socket you intend to use as a 'source'?

Kind Regards, John

 

[JohnW2]

One 2.5mm² T&E from socket to first switch and then on to second - sharing all three - would electrically be sound.

Would it? If the 'source' double socket was on a ring final, the second switch/socket would then be 'a spur off an unfused spur', wouldn't it? A solution would, of course, be to make the two switches part of the ring (until people start talking about switches not being 'to BS7671'!!).

Kind Regards, John

 

[LeeUK]

Sorry if not v clear.

The double socket has 2 - 2.5mm going to it

After thinking (and chiseling) im going to continue with two lots of 2.5 twin

Is that correct?
Do I need to take one off the double and circle it (another not clear question)?

 

[EFLImpudence]

Assuming it is a ring -

One 2.5mm² T&E from socket to first switch and then on to second - sharing all three - would electrically be sound.

Would it?

Yes, I am designing what is electrically sound.

If the 'source' double socket was on a ring final, the second switch/socket would then be 'a spur off an unfused spur', wouldn't it?

Or you can look at it as the same as a double socket.

A solution would, of course, be to make the two switches part of the ring (until people start talking about switches not being 'to BS7671'!!).

A solution would be to use 4mm² cable which cannot be overloaded whatever the circuit.

 

[JohnW2]

If the 'source' double socket was on a ring final, the second switch/socket would then be 'a spur off an unfused spur', wouldn't it?

Or you can look at it as the same as a double socket.

In some senses, yes, but you would surely be violating the App 15 guidance that a 2.5mm² unfused spur from a ring final cannot supply two single sockets - which, although not a regulation, is something with which most people seem to feel they have to comply?

How far would you be prepared to go in regarding such an arrangement as being "the same as a double socket"? What if the two switches were physically separate, rather than two grid switches in the same box? If you would accept that, how far apart would those two switches have to be in order for it to cease to be "the same as a double socket" - 5mm, 50mm, 500mm or what?

A solution would be to use 4mm² cable which cannot be overloaded whatever the circuit.

As often discussed, that's electrically fine - but many seem reluctant to do it because it is not 'mentioned' in App 15. Mind you, I'm not sure that I would really want to play with 4mm² cable in a two-module grid box!

Kind Regards, John

 

[Taylortwocities]

I'm wondering what these two switches are for..?

 

[JohnW2]

I'm wondering what these two switches are for..?

Who knows (until the OP tells us). Given what people often do, and also given the reference to tiling, my money would be on two under-counter kitchen appliances!

Kind Regards, John

 

[EFLImpudence]

Not sure you can violate guidance.

4mm² is much easier to work with than 2.5.