socket on ring or spur?

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Hello again,

Is there any way of telling if a socket is on the main ring or a spur without following the cable all the way? Several sockets in my place have single cables going in, so are obviously spurs. Most of the others have two cables going in, suggesting they are probably on the main ring. I know this is not necessarily the case, though! Is there any test you can do to determine this? I'd be grateful if someone could point me in the right direction.

Thanks
 
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Yes, you'll need a multimeter set to resistance range.

Turn the power off at the main switch and check that no power is on at all, anywhere.

Remove the two wires from the back of the socket and (using the meter) you should get continuity between the two lives, between the two neutrals and between the two earth conductors.

Basically, this shows that socket is on a ring circuit (there are some gotchas but basically that should do you.)

If ther are three cables then one of the cables may be a spur so you will get continuity between two of the cables but not the third.

Just in case you didn't read the preamble above:

Turn the power off at the main switch and check that no power is on at all, anywhere. .
 
Thanks for that. Yes, I will make sure everything is turned off, fuses are pocketed etc. before I check! So as long as all three wire "pairs" show continuity, I can safely assume it's on a ring?

I haven't found any sockets with more than 2 wires yet, the spurs are done with a plug in the front of another socket and the flex run via trunking all the way to the spur, so:

a) As long as the guy who did these did all the spurs, I should be able to spot them easily!

b) As this is a bit of a bodge, if I were to re-wire them using 2.5mm cable in trunking chased in the wall, would I need to notify this? Presumably not, as it's a re-wire? How about if I wanted to re-wire it as an extension of the ring (while I'm at it)?
 
Adding new sockets or fused spurs to an existing Ring Final is not notifiable (unless in Kitchen, Bathroom etc). But adding an unfused spur is!

Replacing existing damaged cable is not notifiable, but I'm not sure if your existing "spurs" really count as part of the "fixed" wiring - although as the cable is in trunking there is case for saying they do (cf: it's been pointed out that running power to a shed etc by just plugging into a house socket does not remove the need to notify as the wiring is still fixed)

So if the cables were (somehow) do be damaged then you might argue you can replace them without notifying - but only if you follow the same cable route, use the same cable type and installation methods, which I doubt you want to do!

Bottom line is that I think that technically this is notifiable. Other will be along shortly to argue I expect (or not)

:)
 
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Thanks.

So if I just remove the spur and extend the ring to the same spot the work isn't notifiable? On the basis that removing the spur isn't notifiable and extending a ring isn't either (unless you increase the floor space served by it by to much)?

I think it's the way to go. Frankly:

1) It looks cr&p.

2) I'm redecorating the room soon anyway (hence the overhaul).

3) If I were to follow the regs on using the same cable type, I would be running a new length of flex some 4 metres in surface mounted conduit. Not best practice really.

I understand the need for the regs, but it's frustrating if you're put in a situation, where in order to re-do a bodge job properly - and improve things - you have to notify the work!

And can anyone give an example where a continuity test would suggest a ring circuit, when in fact it is not? I just want to be doubly sure that I really am extending the ring!

Thanks again for all the comments and help.
 
Thanks.

So if I just remove the spur and extend the ring to the same spot the work isn't notifiable? On the basis that removing the spur isn't notifiable and extending a ring isn't either (unless you increase the floor space served by it by to much)?

I think it's the way to go. Frankly:

I agree. You should still complete the standard tests and fill in a MWC for the additions.
 
Adding new sockets or fused spurs to an existing Ring Final is not notifiable (unless in Kitchen, Bathroom etc). But adding an unfused spur is!

I'm fairly sure that's not true - part P says under the list of non-notifiable work regarding adding additional sockets is:

2. Work which -

(a) is not in a kitchen, or a special location,

(b) does not involve work on a special installation, and

(c) consists of -


(i) adding light fittings and switches to an
existing circuit or

(ii) adding socket outlets and fused spurs to an
existing ring or radial circuit.

I think when they say fused spur, what they mean in that context is an FCU (fused connection unit) to hard wire an appliance in. I'm 99% sure adding an extra socket outlet as a direct spur from the ring is not notifiable...
 
2. Work which -

(a) is not in a kitchen, or a special location,

(b) does not involve work on a special installation, and

(c) consists of -


(i) adding light fittings and switches to an
existing circuit or

(ii) adding socket outlets and fused spurs to an
existing ring or radial circuit.

I think when they say fused spur, what they mean in that context is an FCU (fused connection unit) to hard wire an appliance in. I'm 99% sure adding an extra socket outlet as a direct spur from the ring is not notifiable...

It's unclear. Adding an unfused socket to a radial circuit isn't notifiable. But adding an unfused spur to a socket from a ring circuit?

Either way, I'm going to go for the ring extension while I'm in there.
 
Extending the ring is always a better idea if you can, so I'd always recommend doing that if possible...
 
It reads pretty clear to me, Work which is not in a kitchen, or a special location, does not involve work on a special installation and consists of adding socket outlets and fused spurs to an existing ring or radial circuit is a non-notifiable activity.
Still has to comply with P1 though, even if it is non-notifiable.
 
As this is a bit of a bodge, if I were to re-wire them using 2.5mm cable in trunking chased in the wall, would I need to notify this?
No, as long as it's not in a kitchen or special location. I suggest you familiarise yourself with Schedule 2B.


How about if I wanted to re-wire it as an extension of the ring (while I'm at it)?
Ditto.


Adding new sockets or fused spurs to an existing Ring Final is not notifiable (unless in Kitchen, Bathroom etc). But adding an unfused spur is!
No it's not.

Replacing existing damaged cable is not notifiable, but I'm not sure if your existing "spurs" really count as part of the "fixed" wiring - although as the cable is in trunking there is case for saying they do
Open & shut case, IMO.


(cf: it's been pointed out that running power to a shed etc by just plugging into a house socket does not remove the need to notify as the wiring is still fixed)
Exactly.


So if the cables were (somehow) do be damaged then you might argue you can replace them without notifying - but only if you follow the same cable route, use the same cable type and installation methods, which I doubt you want to do!
There's nothing in Schedule 2B which imposes restrictions like that.


1) It looks cr&p.

2) I'm redecorating the room soon anyway (hence the overhaul).


And can anyone give an example where a continuity test would suggest a ring circuit, when in fact it is not? I just want to be doubly sure that I really am extending the ring!


But you'd need a resistance meter capable of working accurately at low resistances to pick that up.


It's unclear. Adding an unfused socket to a radial circuit isn't notifiable. But adding an unfused spur to a socket from a ring circuit?
It's perfectly clear.

Unless in a kitchen or special location, adding a socket to an existing ring or radial circuit is not notifiable. Adding a fused spur to an existing ring or radial circuit is not notifiable. If you're adding a socket it doesn't make any difference whether you add it by extending the circuit or by making it a spur.
 

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