Ring Junction

[pff]

Hello.
I put some extra sockets in my attic this afternoon by extending what i thought was the ring main but what it turns out to be a socket spur from a socket spur.
To put this right then i need to take a new wire from the last socket of what is now 5 chained spur sockets and connect it back into the ring main where it comes from the ring main.
the spur is fed from a single socket with a double faceplate adaptor thing screwed onto it.
Is it ok to connect the spurs back into the ring in a terminal block in the socket back box? i would probably swap the back box for a double anyway to make life easier so there would be more room but would there be enough room and is this permissable to do?
The only alternatives i can think are putting a junction box in under the socket behind the wall but i thought it would be a bit inaccessible.
i could of course put in a new back box with a blank faceplate and connect it in there but this would be the second last option, only just beating running a new cable because to be honest i have no idea where it goes next but I'm pretty sure both wires go to sockets in exterior walls

Sorry this post is far longer than necessary, but i thought you might need all the details.

 

[ColJack]

photo of the socket you spurred from and the wires at the back of it..

 

[sparkyspike]

Yes you can do this. Terminal blocks can be a bit clumsy, so you could use crimps instead - but you need a crimping tool for this.

Make sure that you are making a complete ring and not a figure of eight configuration.

Or another option is to replace the first socket with a fused spur connection unit.

Oh, and do you know how to prove whether a ring is complete and wired up correctly? I'm only asking because the mistake has already been made and there's no point wiring it up wrong a second time.

 

[spark1]

Pff.
What sort of testing of the circuit did you carry out before starting alteration work ? Also, is this circuit protected by a 30mA RCD ?

 

[pff]

ColJack:
Ok here is the socket that the spur was taken from.
I did not spur from this socket, i added sockets in between the socket spurred from this and a socket spurred from that socket. This is the socket that the new connection will be in so i assumed this is the socket you wanted a photo of.

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• pff
• 25 Aug 2009
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• pff
• 25 Aug 2009
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sparkyspike:
thanks!
I hoped i could do it i just wasn't sure of the regulations about this kind of thing. i will take one wire from the existing ring out of the socket to connect to the end of the spur chain. this will not make any figure of 8's (i think )
spark1:
as you may have already guessed i carried out absolutely no testing, otherwise i probably wouldn't have made such a great mess of it as it is. I have absolutely no formal training of house wiring or regulations and have no idea about testing installations other than making sure everything works. I do have a multimeter and i do check everythings dead before working but other than that i only really break it out for fault finding, or if i put in a metal plated item i will check its not live because i don't know its just a fear i suppose that i don't want to die.
No circuits in my house are rcd protected, i have two brown fuseboxes with i think about 8 or so rewirable fuses with the little coloured dots on them. The fuse for upstairs sockets is red (30A).

[edit] sorry sparkyspike i must have missed the end bit there the first time i read it, yes an fcu was considered but i thought i might as well just hook it all in a ring if i could. i assumed this would be the more correct way of doing it, am i wrong in my assumption?
I would love to know how to test that it is a correct ring if you would share it with me i would be most pleased thanks .

 

[londonboy]

How about spurring off the ring (once youve found it) and installing an RCD fcu, feed your 5 sockets from the load side.
Although restricting you to 13amps at least it will be RCD protected and comply.
An attic shouldn't need much power anyway.

 

[sparkyspike]

You're right to fully extend the ring, although fitting an fcu is perfectly acceptable.

To verify whether you have a ring, or a spur-off-a-spur, do the following:

Work out which socket you want to extend the ring from. Turn off the power, check the socket is dead and remove the front. Work out which cable is the 'spur' cable and pull it to one side. Seperate the remaining 6 conductors. Set your multimeter to 'continuity' or low ohms. Measure between the two live cables first. Then between the two neutral cables. The figure should be almost exactly the same as the conductors will be pretty much the same length. A reading of, say, 0.5Ω would be normal and would indicate a complete ring. Do the same between the two protective conductors. The result should be a bit higher - say 0.8Ω. If none of the conductors show low ohms, then you don't have a complete ring. If only one or two are, then you have a broken or loose connection somewhere which needs investigating.

This is how you verify a ring. It isn't a complete test as it does not measure the earth loop or insulation resistance, but it is a quick way to check that you are not extending a radial circuit or spur.

Your new ring must not service a floor area greater than 100m² in total.

Your new ring must be wired so that one of the cables on the ring circuit is connected directly to your 'spur' cable. Do this with crimps or terminal blocks. At the end of the line of spurred sockets, take a new cable out of the last socket and join directly into the socket which is on the ring. Finally, connect the last cable (originally in the ring socket) back into the socket. You'll end up with two cables joined together and two in the socket itself.

To fully test this circuit involves going inside the consumer unit and also involves using a professional installation tester, so this is best left to an electrician.

 

[ban-all-sheds]

"Photos showing that someone couldn't be bothered to remove sockets when painting the walls."

Not you, I trust?

 

[pff]

londonboy:
the new sockets in the attic are for my server and networking equipment, and i'll probably get into trouble saying this but i would prefer them not to be rcd protected. The whole reason i'm putting them in is because i'm clearing out and flooring my attic and i have a ridiculous extension lead across the length to the server rack, and i thought it would be easier to put in some sockets before the flooring went in.
anyway yes i would consider these sockets to be the least in my house in need of rcd protection.

sparkyspike:
Thanks for the lesson! Ill be sure to check the resistances when i'm finished. just a guess but the protective conductors will be higher resistance because its thinner then? or is there another reason? just curious.
how do i work out a serviced floor space? obviously sockets on every wall of a room will be the area of the room? but if i only have the sockets on one side of my attic does this mean the whole attic counts as serviced area? I think i might be in a bit of hot water then. guess ill get the measuring tape out tomorrow.
I do think i have a spare way in my fusebox now though come to think about it, but i don't really feel confident going that far.
Thanks for clarifying the steps also, i was pretty sure in my own head about what to do but its nice to be sure.
Is there any real need to get this tested properly inside the fusebox? I understand it would obviously be better to do so but is it completely necessary?

ban-all-sheds:
i have to admit this is my bedroom and i did indeed do the decorating.
The wallpaper under the socket is actually the old wallpaper that didn't even get stripped off never mind repainted.
I did get my comeuppance yesterday trying to pull it off the wall.
Stuck like glue.

 

[sparkyspike]

You should RCD protect any socket outlets. If you're worried about losing power to your PCs, then install a UPS. Or at least an RCBO for the circuit. Don't avoid it though.

Yes, CPCs are thinner hence the higher reading.

Testing the consumer unit verifies that

a) Your cable is in good condition and hasn't been damaged.
b) The trip times and currents for both the circuit breaker and the RCD are within safe limits
c) The installation has been correctly wired
d) Other stuff

In other words you are verifying that you are protected from electric shock and fire

 

[pff]

So it turns out my floor area is 110m2

Time for a new plan I think.
If i use a spare fuse in my fusebox for a new circuit would i be better with a ring or a radial?
The fuse at the moment is rated at 20A but i could swap this out for a replacement?
I would be looking at 6 to 8 double sockets covering my attic floorspace of about 60m2.
I would obviously get a qualified person to wire this into the fusebox as i don't particularly want to take my fusebox apart because theres no isolation other than pulling out the main fuse and i really don't fancy that, but i could probably lay the cable and wire the sockets?

Sorry if i should have started a new thread... :s

 

[ColJack]

100m² floor area is not used anymore.. it was only ever a guideline anyway..

there is a maximum length on the cable but not a maximum area to be served..

 

[spark1]

Pff.

So now your plan is a new circuit back to the fusebox.

Your next step has 2 options..


1. Notify your local Council Building Control department...or

2. Contact an Electrician who is registered with a Self-Certification Scheme.

This work is a Controlled Electrical installation under The Building regulations !

 

[pff]

ColJack:
length of the cable? thats even worse! ill have to do some conservative estimating then about the cable route... what exactly is the figure? i hope it's long enough..

spark1:
Are these under this Part P regulations thing i keep hearing so much about? I understand these only cover England and Wales. Does this change nature of the work being in Scotland? Obviously i will not undertake the actual connection myself or without testing, (i don't want my house burning down) i would just like to know where i stand and what work i am able to take on should i feel that i could. Is there somewhere i can get this information? I have looked around and theres many websites showing me how easy it is to upgrade a consumer unit with no mention of building regulations other than to contact an electrician if in doubt about something.
Is the self certification scheme along the same lines as becoming a competent person? where can i find out more about this?

 

[DCC]

To put this right then i need to take a new wire from the last socket of what is now 5 chained spur sockets and connect it back into the ring main where it comes from the ring main.

Hold up, isn't this describing a ring connected to a ring not a single ring? Could be wrong but I thought that was a no no?