Replacing spur one gang socket for two gang

[u0362565]

Hi all,

I have a single surface mounted socket in a cupboard which our freezer is plugged into. We don't have any sockets in our hall which the cupboard is off so I thought it might be useful to change the one gang socket for a two gang, again surface mounted to keep it simple.

Its on our socket ring main and must be a spur as there is only one cable to it not loop in and out. In theory I think all I need to do is remove the old one gang socket and screw on a two gang box in its place, I would just use the existing supply to the old socket.

Assuming I'm right on the above? Seems like a simple job. Any regulations I should be worried about here? Given I'm literally just replacing the surface box and not changing any wiring? Is this notifiable?

Thanks for the advice

 

[buzzlightyear]

none crack on. replace single to a double .

 

[Spoon]

Is this notifiable?

You are not installing a new circuit so it's not notifiable.
Is the circuit RCD protected?

 

[Toneyz]

No, the job is not notifiable.
As long as the existing socket is spurred directly off the ring final circuit and you are competent in undertaking the job I see no problem. Just remember safe isolation (not by a neon screwdriver) The socket needs to be RCD/RCBO protected.

 

[buzzlightyear]

read . million songs

 

[Pete999]

Hi all,

I have a single surface mounted socket in a cupboard which our freezer is plugged into. We don't have any sockets in our hall which the cupboard is off so I thought it might be useful to change the one gang socket for a two gang, again surface mounted to keep it simple.

Its on our socket ring main and must be a spur as there is only one cable to it not loop in and out. In theory I think all I need to do is remove the old one gang socket and screw on a two gang box in its place, I would just use the existing supply to the old socket. Suitable checks need to be done prior to just swapping the socket Willy Nilly, an Electrician will be able to check this for you.

Assuming I'm right on the above? Seems like a simple job. Any regulations I should be worried about here? Given I'm literally just replacing the surface box and not changing any wiring? Is this notifiable?

Thanks for the advice

If the existing single socket is truly a spur, and not a spur off another spur the just swap the single for a double. If hower it has been spured from another spurred outlet then more work will be required.

 

[u0362565]

You are not installing a new circuit so it's not notifiable.
Is the circuit RCD protected?

Yes its RCD protected, there are 8 circuits on the CU each protected by MCB's and then there are 2 RCD's which protect 4 of the circuits each.
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Thanks all for the comments

 

[Spoon]

As @Pete999 has mentioned, just make sure it's an actual spur from the RFC (Ring Final Circuit) and not a spur of a spur mate.

 

[u0362565]

Ok so I've had a closer look at this and noticed something but don't think it affects me converting one gang to two gang. The cable from the ring main goes to a fused switch. From the switch there is a cable out to the socket and a cable out to the ceiling light in the cupboard. The cables terminate at these loads and do not go elsewhere.

Going back to what Pete999 & Spoon said, assuming it is a spur off the ring main is the fact that it is supplying a light and a socket still classed as a single spur? And how do I determine that its not a spur off a spur? In theory it shouldn't be as if the work was done properly then no one should have done that in the first place? I realize you should never assume.
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The fused switch only operates the light as expected and does not cut power to the socket.

 

[Spoon]

The cable from the ring main goes to a fused switch.

So in your first paragraph above you are only assuming it wires to the RFC.

Going back to what Pete999 & Spoon said, assuming it is a spur off the ring main is the fact that it is supplying a light and a socket still classed as a single spur? And how do I determine that its not a spur off a spur? In theory it shouldn't be as if the work was done properly then no one should have done that in the first place? I realize you should never assume.

See where this fused switch wires back to.
You can test the circuit to determine what type of circuit it is.

 

[u0362565]

So in your first paragraph above you are only assuming it wires to the RFC.



See where this fused switch wires back to.
You can test the circuit to determine what type of circuit it is.

Hmm I can't track the incoming wire as it disappears into the wall, would need to pull up floor boards etc to track it. I do know that when I switch off the MCB to the ring main the light and socket are cut off but that doesn't answer if its a spur off a spur.

 

[Spoon]

Hmm I can't track the incoming wire as it disappears into the wall, would need to pull up floor boards etc to track it. I do know that when I switch off the MCB to the ring main the light and socket are cut off but that doesn't answer if its a spur off a spur.

Do you have any test equipment?

 

[telectrix]

lost count of the number of times i seen more than 1 socket on an unfused spur. even hold hands up to doing it myself on occasions where the load is low e.g. laptop, phone chargers etc.

 

[Pete999]

They said it all
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Ok so I've had a closer look at this and noticed something but don't think it affects me converting one gang to two gang. The cable from the ring main goes to a fused switch. From the switch there is a cable out to the socket and a cable out to the ceiling light in the cupboard. The cables terminate at these loads and do not go elsewhere.

Going back to what Pete999 & Spoon said, assuming it is a spur off the ring main is the fact that it is supplying a light and a socket still classed as a single spur? And how do I determine that its not a spur off a spur? In theory it shouldn't be as if the work was done properly then no one should have done that in the first place? I realize you should never assume.
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The fused switch only operates the light as expected and does not cut power to the socket.

From your description and my guesswork it looks like the light is wired through the LOAD side of the FCU and the socket is wired to the feed side pf the FCU, not an ideal method in my opinion needs checking out by someone competent.,

 

[u0362565]

The only equipment I have is a multimeter and Fluke non-contact voltage tester. I ran it past a colleague at work who has done the edition 18 exams and they thought it was ok if its not a second spur but as thats hard to determine maybe I'll just leave it.

 

[davesparks]

The cable from the ring main goes to a fused switch. From the switch there is a cable out to the socket and a cable out to the ceiling light in the cupboard. The cables terminate at these loads and do not go elsewhere.

How many cables are there coming in to the switch fuse?

 

[Pete999]

How many cables are there coming in to the switch fuse?

2 RFC and 1lighting cables by the description???? 1 from the RFC 1 to the new socket and 1 to the light??

 

[davesparks]

2 RFC and 1lighting cables by the description???? 1 from the RFC 1 to the new socket and 1 to the light??

It's not totally clear to me from the description, obviously if it is as you describe then the SFCU is already on a spur.

 

[u0362565]

There are 3 cables to the fused switch only, supply from RFC (assumed). One cable out to light and one to the socket. From what I have read tonight you should either have a junction box off the RFC to a 13A fused spur or junction box to unfused spur with switching and local protection (sounds like my fused switch) so perhaps what I have is the latter.

 

[davesparks]

There are 3 cables to the fused switch only, supply from RFC (assumed). One cable out to light and one to the socket. From what I have read tonight you should either have a junction box off the RFC to a 13A fused spur or junction box to unfused spur with switching and local protection (sounds like my fused switch) so perhaps what I have is the latter.

I don't know where you have read that, but it is not an accurate representation of the regulations.
An unfused spur is a single cable connected to a ring circuit at an accessory or a junction box, this is permitted to feed one, and only one, point. That point can be a single socket twin socket (but not two singles), fused connection unit (FCU) or switched fused connection unit (SFCU)
A fused spur is connected to a ring circuit via an FCU or SFCU, this can supply as many points as you like as long as the cables are suitably sized etc etc.

What you have described is an unused spur feeding two points, the first point is an SFCU and the second point is the socket you wish to change. This is not permitted by the regulations.

Have you confirmed that the circuit is in fact a ring circuit? What is the rating of the circuit breaker which feed it?

 

[Grant1987]

I don't know where you have read that, but it is not an accurate representation of the regulations.
An unfused spur is a single cable connected to a ring circuit at an accessory or a junction box, this is permitted to feed one, and only one, point. That point can be a single socket twin socket (but not two singles), fused connection unit (FCU) or switched fused connection unit (SFCU)
A fused spur is connected to a ring circuit via an FCU or SFCU, this can supply as many points as you like as long as the cables are suitably sized etc etc.

What you have described is an unused spur feeding two points, the first point is an SFCU and the second point is the socket you wish to change. This is not permitted by the regulations.

Have you confirmed that the circuit is in fact a ring circuit? What is the rating of the circuit breaker which feed it?

Sounds a bit messed up call a sparky in mate at least you know it’s all safe and sound then ?

 

[u0362565]

Its on a 32A MCB and is labelled "ring main" on the CU. The SFCU has a 13A fuse. So what they should have done in this case is connect the SFCU directly into the ring then attach 2 spur cables off of this, one to the light and one to the socket? I don't know why they didn't put the light into the lighting circuit to be honest.

Why have they used the SFCU in this way? I guess because it allows connection to two points and some protection via the fuse? Does the fuse protect both connections (light+socket)?

The single socket is attached to a freezer so that's draws current much of the time, the light has a 14W bulb and is only only for short periods while accessing the freezer. How dangerous is this? It certainly sounds like I shouldn't change the single socket for a double then as that will put the spur under more load potentially.

Thanks for the explanation.

 

[Toneyz]

Was it not up to the end of the 15th that you could have a spur off a spur?

 

[davesparks]

Was it not up to the end of the 15th that you could have a spur off a spur?

At one time it was permitted to have two sockets on an unfused spur, this could be either one twin socket or two single sockets.

 

[u0362565]

So it proably meets the old regs then, I just won't make any further changes

 

[Pete999]

Its on a 32A MCB and is labelled "ring main" on the CU. The SFCU has a 13A fuse. So what they should have done in this case is connect the SFCU directly into the ring then attach 2 spur cables off of this, one to the light and one to the socket? I don't know why they didn't put the light into the lighting circuit to be honest.

Why have they used the SFCU in this way? I guess because it allows connection to two points and some protection via the fuse? Does the fuse protect both connections (light+socket)?

The single socket is attached to a freezer so that's draws current much of the time, the light has a 14W bulb and is only only for short periods while accessing the freezer. How dangerous is this? It certainly sounds like I shouldn't change the single socket for a double then as that will put the spur under more load potentially.

Thanks for the explanation.

What a lighting point and a 13 Amp twin socket all protected by the same fuse in an FCU?

 

[u0362565]

I'm just asking if what is there now is safe i.e. the light and the single socket off of the SFCU? Seeing as by the old regs you could have 2 singles or one double socket. Ok I have a single and a light but that would draw less current than having two sockets in use. As this doesn't meet the 18 regs I won't replace the single socket for a double as seems it won't be up to standard. What was there before is what it is, I'm not about to go around updating any electrical issue that doesn't meet the 18th as its not practical.

 

[Toneyz]

As this existing socket is in the understairs cupboard with a freezer plugged in what do you intend to plug in it? as if it is for anything outside of this cupboard you will have to have the door open.

 

[u0362565]

I could have the door closed as the average cable will fit under the door. Anyway it's not a big deal I just initially thought it was a straightforward job that wouldn't cost much to do compared extending the circuit and having a socket put in the hall. Given what's been said will leave alone.

 

[Gnasher]

Additionally, although not notifiable all work/modifications should be covered by a test certificate of some kind. In this example a MNW cert.

 

[Toneyz]

The word there being SHOULD your average DIY'er is not going to have the test kit costing £100's. for putting in an extra socket etc.

 

[Gnasher]

Fair point.
This then highlights a much bigger frustration. How can DIY work be carried out without sufficient certification.
Not sure I can answer this one.