Old MK Metal back box too wide to fit 2-Gang DP Switched plug socket

[Colindr]

Hi all - just wondering if there is a way round this;

I want to try and fit and wire up a 2-Gang MK plug socket to allow me to hook up a wall mounted TV more directly instead of using long extension cable. The previous electric connection was to an old 'Honeywell' heating thermostat that was decommissioned when I had the central heating upgraded. The electrician who decommissioned it, even remarked that I could replace this with a double plug socket.

However when I take off the blank cover plates the metal back box appears to wide and a narrow to accept my new double socket front plate and the screw-holes don't line-up. The back box is 150mm wide and there's a measurement of 140mm from screw to screw-hole. The front plate I bought from screw fix is 120mm to each screw. The actual length of the whole front-plate is 145mm so only 5 mm less than the back box. Is there any special adopter/attachment you can buy to line-up the screw-points, so I don't need to remove the metal back box currently in place.

 

[DetlefSchmitz]

You could use two single sockets as that is what the backbox is designed for. You would need to check what this is supplied from though.

 

[EFLImpudence]

That is what is called a 'dual' box which is used for two single sockets or a single socket and a fused connector unit.

If you want to fit a 'double' socket like you have then you will have to replace it with a 'double' back box.

 

[Colindr]

You could use two single sockets as that is what the backbox is designed for. You would need to check what this is supplied from though.

Thanks for quick reply... If I were to use 2 single sockets would I just wire up the live, neutral & earth wires from each cable separately to each socket? I'm not sure what you mean by what is it supplied from? Is it not just wired up from the consumer unit as per all other switches in the living room? I notice the one cable on the bottom right which is cut-off is 'redundant' I've checked with a non-contact voltage tester and it doesn't light up/beep, were it does with the other wires in their terminal brackets.

That is what is called a 'dual' box which is used for two single sockets or a single socket and a fused connector unit.

If you want to fit a 'double' socket like you have then you will have to replace it with a 'double' back box.

Thanks... I suppose for the professional look and appearance it would make sense to replace it with an appropriately sized double socket back box. I think it's 35mm in depth. I can see the screws holding the old back box in place, so hopefully it will just ease out when I undo them. I might have to use filler/padding to close that 0.5cm gap at both end sides. Cheers.

P.S. does it matter when I replace the metal back box, if I were to replace it with a moulded plastic one, or does it have to be metal?

 

[flameport]

Thanks for quick reply... If I were to use 2 single sockets would I just wire up the live, neutral & earth wires from each cable separately to each socket?

That's part of it - you also need to link both of the single sockets together, L-L, N-N, E-E.

That also assumes that those wires are for a socket outlet circuit, and that there is an RCD protecting that circuit.

so hopefully it will just ease out when I undo them

There will be some damage, as you will need to pull the lower edge of the box out first so that you can remove the cables from the top.
Get a metal box - plastic ones are not designed to be flush in a wall.

 

[DetlefSchmitz]

Removing the backbox will create more damage than you expect, and leave a gap at each end. I wouldn't change it myself.

 

[Sureitsoff?]

you could also fit a single socket and a blank plate

 

[Jakg]

P.S. does it matter when I replace the metal back box, if I were to replace it with a moulded plastic one, or does it have to be metal?

Plastic ones are typically for surface mounting, whereas metal ones go into the wall.

It's unlikely you'll be able to swap the back box without some degree of making good afterwards.

 

[Colindr]

Thanks for input guys,

I did consider the one-socket option but really could do with two to accommodate the TV and cable box, instead of using double adaptors, extension leads etc...

Well I decided to remove the old back box and despite a bit of rubble coming out (mainly from the top right) it wasn't too bad although part of the (right as you see it) screw holding the back box broke off but I managed to twist it out using hand-grip pliers.

...It's unlikely you'll be able to swap the back box without some degree of making good afterwards.

...that's the stage I'm at now.... temporarily placing the new smaller back box into the space it wedges quite nicely up to the (left as you view it) and I can use the previous drill hole to screw that side in. It's sits flush on it's outer surface edges to hopefully accept the double socket face plate, but this will now leave me with a approx 3 cm of gap on the right ... what's the best way of filling this in...I presume I will need to apply finishing touches using filler but do I use a spare piece of wood or expanding foam to fill the main void at the side? Cheers.

 

[phatboy]

A small bag of readymix mortar would do the job, and it would hold the box in place, with some filler to make good. But a piece of timber backed onto some gripfill or sticks like **** would be equally as good.

Don't know why you bothered to remove the old box, 2 single sockets would have been absolutely fine and about 10 minutes work!

 

[winston1]

... what's the best way of filling this in..

Bonding plaster.

 

[JohnW2]

Don't know why you bothered to remove the old box, 2 single sockets would have been absolutely fine and about 10 minutes work!

Very true (in fact, arguably even better) - but maybe the OP had already bought a double socket?

Kind Regards, John

 

[phatboy]

Very true (in fact, arguably even better) - but maybe the OP had already bought a double socket?

Kind Regards, John

Now he has to go buy a bag of ready-mix or bonding plaster though... would have been cheaper to return the double metal box and socket, and replace with 2 singles! Nevermind....!

 

[sparkwright]

Look, if he wants a double socket rather than two single sockets, then there's no problem.

Personally I prefer the look of one double instead of two singles, and I would too would probably go the extra mile if I was prepared to do some making good.

 

[Colindr]

Thanks all...your right I probably have created a bit more work for myself but I had already bought the double socket and was so focused on that old box being the wrong size it didn't dawn on me that I could have used single sockets.

Oh well it will keep me busy and occupy my time for a bit. Cheers