Replacing single socket with double - attaching box to wall.

[EFLImpudence]

There are other factors at play here too. At the moment I’m leaning more towards wanting to get someone to come in and do the work for me.

I think that would be wise.

 

[EFLImpudence]

If you have 'two sets' of cable at the existing socket, 2x reds(or browns), 2x blacks (or blues), plue two earths, that simply means the socket is on a ring.

OR a radial or a spur - either wrongly installed or installed with suitable cable.

Nothing complicated about it, the ring begins at the consumer unit, goes round/through all the sockets, then back to the consumer unit.

...but is indistinguishable from the other options.

 

[Murdochcat]

If you have 'two sets' of cable at the existing socket, 2x reds(or browns), 2x blacks (or blues), plue two earths, that simply means the socket is on a ring. Nothing complicated about it, the ring begins at the consumer unit, goes round/through all the sockets, then back to the consumer unit.

Oh dear. The blind leading the blind

On a radial circuit all sockets except the last one, and any spurs of the radial have one cable. This means all the others have 2 cables

2 cables means radial OR ring

 

[Nope]

Alright everyone, I’ve been doing a bit of investigation this afternoon and there doesn’t seem to be any rhyme or reason to how my sockets are wired. In the CU I have 7 MCBs controlling sockets. Six of those are 16A MCBs and seem to control no more than one or two sockets, and the 7th is a 32A MCB and seems to control everything else. Since I can’t guarantee whether these are ring or radial I’m going to just leave it in the hands of a professional.

 

[Nope]

Why go to all that trouble and expense, in my study, I just use a four socket extension lead with surge protection.

Because we have too many things to plug in and not enough sockets and I’m not a fan of overloading extension cables!!

 

[LeeJC]

Alright everyone, I’ve been doing a bit of investigation this afternoon and there doesn’t seem to be any rhyme or reason to how my sockets are wired. In the CU I have 7 MCBs controlling sockets. Six of those are 16A MCBs and seem to control no more than one or two sockets, and the 7th is a 32A MCB and seems to control everything else. Since I can’t guarantee whether these are ring or radial I’m going to just leave it in the hands of a professional.

Hi Sam,

That's sound investigation.
What you've discovered (large assumption here on correct installation) is

You have 6 Radial circuits running to sockets (the 16Amp circuits with a single 2.5mm T&E connections)
You either have a 2.5mm T&E Final Ring or a 4mm T&E Radial.
I'm not sure I'm allowed to suggest what I would do next, but it would be around isolating your incoming supply and trying to ascertain the cable dimensions at entry into each breaker.

As someone has suggested if your cables are too short you can use inline Wago connector to extend the cable, ensuring it's the same dimensions as the installed cable.
If the 2 sockets you want to convert to 4 are on one of these radial branches then they remain appropriately protected by the 16 Amp Breaker.
If the 2 sockets you want to convert to 4 are on the arrangement from the 32 Amp breaker then with correct cable selection you will remain protected.

You are perfectly capable of doing this, you've already done work that allows you to know which outlets are connected to which breaker.

 

[LeeJC]

If it's this paragraph that's causing you concern.

'With the circuit isolated you can safely undo the screws on the front of the socket. If there’s just one wire per connector (earth, live and neutral) it means that the socket has already been spurred off another; you can change this into a double socket but you can’t spur off it to supply a new outlet. Two wires going into each connector indicates that the socket is either part of the ring main or that it is one of two sockets fed by the same spur. If you plan to swap a single socket for a double or add a new spur, you must make sure that the outlet is part of the ring main. To check, you need to run the continuity test in the next step.'

Then I would discount most of the stuff after you can safely undo the screws on the front of the socket. The Author is entirely ignoring the Radial type installation and assuming that every house only has Ring Finals installed so anything that's a single conductor must be a spur.

He's wrong.

 

[Harry Bloomfield]

Oh dear. The blind leading the blind

There are none so blind, as those who will not see, and you seem especially blind and irrelevant - posting unnecessary complications, despite many in here disagreeing with your stance.

On a radial circuit all sockets except the last one, and any spurs of the radial have one cable. This means all the others have 2 cables

And if it is a radial circuit, it will make zero difference at all. The advice holds perfectly good, so I suggest you crank your neck back in. I wonder how you view a 13 amp socket, added to a lighting circuit?

 

[Harry Bloomfield]

Alright everyone, I’ve been doing a bit of investigation this afternoon and there doesn’t seem to be any rhyme or reason to how my sockets are wired. In the CU I have 7 MCBs controlling sockets. Six of those are 16A MCBs and seem to control no more than one or two sockets, and the 7th is a 32A MCB and seems to control everything else. Since I can’t guarantee whether these are ring or radial I’m going to just leave it in the hands of a professional.

Don't be put off by that Murdoc troll, simply find out which MCB supplies the socket we are interested in, and report back..

 

[Harry Bloomfield]

You either have a 2.5mm T&E Final Ring or a 4mm T&E Radial.

2.5mm will be a single strand (if modern), 4mm will have seven strands..

 

[Nope]

Don't be put off by that Murdoc troll, simply find out which MCB supplies the socket we are interested in, and report back..

Hi Harry,

Based on my detective work (and with the help of a tester pen and socket tester from Screwfix) I’ve determined the following:

The two sockets in the study are on different circuits. Socket #1 at my wife’s desk is the one that has 2 sets of wires in it. It’s connected to MCB #7 in the CU, which is 32A and seems to be the ring circuit. Socket #2 at my desk is connected to MCB #1, which is a 16A MCB. The only other socket I can see connected to this MCB is in our guest room, on the other side of the house but in the same position on the wall (back wall, under the window in the corner).

I don’t know which of these two sockets is first in the spur, but I suppose opening it up would allow me to see how many wires there are.

 

[Murdochcat]

There are none so blind, as those who will not see, and you seem especially blind and irrelevant - posting unnecessary complications, despite many in here disagreeing with your stance.

disagreeing with what precisely. What I have stated is technically and factually correct, whilst you have been stating inaccuracies to say the least

 

[Nope]

If it's this paragraph that's causing you concern.

'With the circuit isolated you can safely undo the screws on the front of the socket. If there’s just one wire per connector (earth, live and neutral) it means that the socket has already been spurred off another; you can change this into a double socket but you can’t spur off it to supply a new outlet. Two wires going into each connector indicates that the socket is either part of the ring main or that it is one of two sockets fed by the same spur. If you plan to swap a single socket for a double or add a new spur, you must make sure that the outlet is part of the ring main. To check, you need to run the continuity test in the next step.'

Then I would discount most of the stuff after you can safely undo the screws on the front of the socket. The Author is entirely ignoring the Radial type installation and assuming that every house only has Ring Finals installed so anything that's a single conductor must be a spur.

He's wrong.

Yeah that’s pretty much the paragraph that was concerning me!

 

[Nope]

Hi Sam,

That's sound investigation.
What you've discovered (large assumption here on correct installation) is

You have 6 Radial circuits running to sockets (the 16Amp circuits with a single 2.5mm T&E connections)
You either have a 2.5mm T&E Final Ring or a 4mm T&E Radial.
I'm not sure I'm allowed to suggest what I would do next, but it would be around isolating your incoming supply and trying to ascertain the cable dimensions at entry into each breaker.

As someone has suggested if your cables are too short you can use inline Wago connector to extend the cable, ensuring it's the same dimensions as the installed cable.
If the 2 sockets you want to convert to 4 are on one of these radial branches then they remain appropriately protected by the 16 Amp Breaker.
If the 2 sockets you want to convert to 4 are on the arrangement from the 32 Amp breaker then with correct cable selection you will remain protected.

You are perfectly capable of doing this, you've already done work that allows you to know which outlets are connected to which breaker.

Thanks for this. How would I determine the sizes of the cables?

 

[Sureitsoff?]

can you post any pics so that we can assist