Problem adding sockets

[Hagarbloke]

Could do with some advice on this one if you guys can help. I'm trying to add a few extra sockets into the smallest bedroom which is soon to become my workshop. Currently there's only one single outlet near the door and I wanted to add two dual gang sockets on another wall. I checked behind the existing single socket and found a cable coming in, and a cable coming out so assumed this socket was on a ring and was simply going to extend it. However, I've just removed the socket, separated the two lives and found that only one of them is live with respect to the two neutrals. If this was indeed a ring, shouldn't they both be live? Also, behind the socket you can see a dual gang socket in the next room which has three cables running to it.
Any ideas on what might be going on? We only moved in about 8 months ago and I know that whoever wired it was a right numpty, as I found a metal light fitting on the wall with the live connected in a bit of taped up choccy block and the earth wire cut off completely!

 

[rebuke]

My best guess would be that the socket you're working on is spurred off of the one in the next room, and someone has (wrongly) run another spur off of the one you're working on.

This is just a guess though, you'd have to go round testing each socket to determine if it's correct or not...

 

[ColJack]

wasn't me.... I didn't do it .

like you say, some numpty has spurred off more than 1 socket from a spur..

you can take a live out of the other socket in the next room and put it in the single, and use it and the other live in the double as points to extend the ring to the new sockets.

 

[PrenticeBoyofDerry]

Sounds like spur on spur. If theres another socket close by I'd see if that was dead too. When you disconnect your single socket in bed/work room.
You could replace it by a Fused Connection unit and run some sockets of that

 

[wingcoax]

To maintain the ring follow what Coljack says, it might be a bit trickier at first but it will be better in the long run.

 

[Hagarbloke]

Thanks chaps, checked and that's exactly what's been done. The single socket in my workshop is a spur off the ring on the double socket in the next room. I disconnected this and followed it to a single socket on the landing. Strange thing is, this landing socket has another cable connected to it aswell (a spur off a spur off a spur somewhere?!) I left this circuit disonnected and turned the power back on, but all the other outlets throughout the house work, so I wonder where this extra cable off the landing socket goes?!

 

[ColJack]

need to trace it..

 

[Hagarbloke]

Well I've left this circuit disconnected for now, we don't use the landing socket anyway. I just can't understand why nothing else is affected by this. Perhaps the cable has just been left unterminated under the floor boards somewhere? (which wouldn't surpirse me given the state of the rest of the wiring in this house). It's not live, so won't it be ok to just leave it for now? We'll be replacing the carpet eventually, but probably not til next year. I could get the boards up and try to trace it then.

 

[nozspark]

Be very careful what you disconnect and what you leave connected....

Lets call the cables 1 & 2

If
L(1) - N(1) =240v
L(1) - N(2) =240v
L(2) - N(1) =0v
L(2) - N(2) =0v

Then you could have a ring which has an open circuit L conductor on one leg!

You really need to trace the cables out fully or get an electrician in to figure it out for you..

 

[ColJack]

I'll be round saturday morning.. have a backon and egg ready as payment...

 

[Hagarbloke]

Be very careful what you disconnect and what you leave connected....

Lets call the cables 1 & 2

If
L(1) - N(1) =240v
L(1) - N(2) =240v
L(2) - N(1) =0v
L(2) - N(2) =0v

Then you could have a ring which has an open circuit L conductor on one leg!

You really need to trace the cables out fully or get an electrician in to figure it out for you..

That's just confused the hell outta me.

ColJack..........Bacon & egg and several cuppa's.........deal.

 

[Inky Pete]

Well I've left this circuit disconnected for now, we don't use the landing socket anyway. I just can't understand why nothing else is affected by this. Perhaps the cable has just been left unterminated under the floor boards somewhere? (which wouldn't surpirse me given the state of the rest of the wiring in this house). It's not live, so won't it be ok to just leave it for now? We'll be replacing the carpet eventually, but probably not til next year. I could get the boards up and try to trace it then.

Could it go up into the loft? Lights up there or a socket for a TV aerial booster perhaps?

 

[Hagarbloke]

I thought that Pete, but there are no outlets or lights in the loft that I can see. I'm just concerned now after nozspark's comment. This circuit is now not live so it can't be connected to anything other than an outlet or supply to something else can it? The dual gang socket I mentioned in the next bedroom appears to be on the ring, as when I seperate the lives they are both live with respect to the neutrals. I've broken into this ring and added the extra sockets I need in the workshop and everything seems to be working fine. It's just the one on the landing and wherever that runs to next that's confuzzling me.

 

[PrenticeBoyofDerry]

What about old boiler connection or something in the bathroom that has been decommisioned.
Again if you wish to add sockets in the work room area you can put a FCU ideally an RCD FCU if your CU has no RCD protection, if you are extending the ring fina.l I'd be putting an RCBO on circuit to protect it, if you have no RCD protection already on that circuit.

 

[Hagarbloke]

I suppose the only way of knowing exactly where it goes is to get the boards up and trace it, just not in a position to do that just yet. All I'm getting at is will it be ok to leave it for now as it's not live?

The CU in the kitchen IS an old one without RCD protection. One of the sockets I'm adding to the workshop will have a built in RCD and I'll use this outlet for working on/testing live equipment (i'm an electronics engineer). The other two sockets will power bench test equipment like my scope, meters and variable power supply. When budget allows I plan to get the CU replaced for a modern one with RCD protection. I've recently replaced the shower but not using it yet until the new CU is in place.