2 gang trailing socket hardwired in place of 2 gang switched socket

[MattsFlat]

Dear all,

I've seen this covered on other, older threads, but don't feel a full explanation has been offered around what is compliant with the regs, and what isn't.

I would like to hardwire a two-gang trailing socket in place of a surface mounted two-gang switched socket that is on our 'downstairs sockets' circuit with a 32A MCB and a 80A/30mA RCD. The reason for this is that it is hard up behind a sofa and impossible to use with the room configured as is. It's an old stone cottage with few sockets. I would use 2m of 3-core flex, which can be 2.5mm2 (the same as the T&E on the existing circuit).

It seems to me this is no different than repositioned the existing socket with 2m more of T&E. Would there be any need to add a fused spur unit? The only issue I can see is a mechanical one, if the socket was tripped over/yanked. I'd imagined using a blank and one the punch outs with some sort of strain relief clamp to mitigate for this.

Looking for understanding about a)the regs and b)any safety issues about my proposal.

Thanks in advance.

 

[EFLImpudence]

I would like to hardwire a two-gang trailing socket in place of a surface mounted two-gang switched socket that is on our 'downstairs sockets' circuit with a 32A MCB and a 80A/30mA RCD.

Why and how would the new trailing socket (extension lead) replace the wall socket and not just be connected to it as a spur?

 

[MattsFlat]

Thanks for your response. Because the existing socket will be removed and I'll use Wago connectors or something similar to join the existing T&E to the 3 core flex, if that makes sense.

 

[Sureitsoff?]

could you not just plug in a 2m ext lead? much simpler

 

[EFLImpudence]

Ok.

Then as you have said, a method of cable restraint will be required to prevent the flex being pulled out.

With only one or two sockets on the lead a Fused Connector Unit - the cable is the spur - will not be required.

 

[DetlefSchmitz]

It sounds unusual not to have room behind a sofa for a plug and socket. Still, you must have looked behind it and seen.

 

[RandomGrinch]

Then as you have said, a method of cable restraint will be required to prevent the flex being pulled out.

Which is conveniently included with an FCU

...two gang extension blocks with an integrated fuse holder are rare - another reason for an FCU?
these blocks would not fare well with a combined load of 26A!

 

[EFLImpudence]

Which is conveniently included with an FCU

And indeed on a plain Flex-outlet plate..

 

[Sureitsoff?]

flat plate socket, legrand plug (18mm projection) so about twenty mm overall from the wall. there surely must be room for that.

 

[plugwash]

My understanding is that trailing sockets are only rated at 13A total, which is a fair bit less than a normal double socket outlet. The flex of an extension lead is also substantially smaller than the cable required for a ring. You could probablly just about get 2.5mm² flex into a trailing socket but it be a tight fit.

I would thus use a FCU to provide the trailing socket with the same level of protection it would have if plugged in.

 

[oldbutnotdead]

Be much easier just to buy an extension lead and plug it in.
If that's not possible then the better bet will be FCU with your (1.5mm) extension wot you bought terminated in it.
2.5 flex is hard work into plugs and into FCUs. Trailing socket would be OK (use a metalclad socket with a gland, NOT a pattress box and standard socket).
I've always taken the 'you can spur one socket from an existing socket without FCU etc' to mean a SINGLE socket, not a double or more. Might be wrong, dunno.

 

[EFLImpudence]

I've always taken the 'you can spur one socket from an existing socket without FCU etc' to mean a SINGLE socket, not a double or more. Might be wrong, dunno.

You are indeed wrong.

 

[opps]

My understanding is that trailing sockets are only rated at 13A total, which is a fair bit less than a normal double socket outlet. The flex of an extension lead is also substantially smaller than the cable required for a ring. You could probablly just about get 2.5mm² flex into a trailing socket but it be a tight fit.

I would thus use a FCU to provide the trailing socket with the same level of protection it would have if plugged in.

I was thinking something similar.

Although the flex may be rated at 27amps, the double socket may only be rated at 13amps. Regardless the 32amp fuse in the CU is over rated for the flex... unless I am missing something (which is my default state).

 

[RandomGrinch]

Although the flex may be rated at 27amps, the double socket may only be rated at 13amps.

That was what I was trying to get at (may be too subtle ) with:

these blocks would not fare well with a combined load of 26A!

But the information we are missing is what type of trailing "two-gang trailing socket", is the OP talking about.
Is it one of these, with 2.5mm cable and suitable grommets:

Or is it one of these, that definitely wouldn't cope with a sustained 26A load!

 

[MattsFlat]

flat plate socket, legrand plug (18mm projection) so about twenty mm overall from the wall. there surely must be room for that.

It's a small cottage with stone walls, and while the cables have been chased out there is not a back box, but a surface mounted box and socket which protrudes 4cm from the wall. Add a normal 13A plug and that's 6cm odd. The sofa is one with a flat back kind of wedged in, and there simply isn't room for a plug. I have tried, I promise.