Spur from a spur

[davejuk]

My loft lights are on the upstairs lighting ring and the double socket is on the upstairs sockets ring. Although the lights appear to be in the ring itself, the socket is a spur with only one 2.5mm/30A cable going into it.

I need to add at least one more double socket, possibly two. I understand that to conform with the regs a new spur from the existing spur must be fused at 13A.

So I need to come off the existing socket to one of those little fused face plates like I have in my kitchen and then connect that to my new socket?

And what if I need to draw more than 13A? Can I add a second double socket?

 

[PrenticeBoyofDerry]

You cannot introduce a 13A FCU after the existing spur, the 13A FCU must be at the point where the first spur is taken, straight from the ring final circuit before the first socket spurred. This would then only allow a max 13A demand.
To increase this demand, you would need to extend the ring final circuit as a whole not as a spur.

 

[davejuk]

Thanks for the reply.

So long and the short of it is that I need to find where this spur joins the ring?

Other than that, my only option is to plug an extension into the existing socket with a multi-socket adaptor?

 

[PrenticeBoyofDerry]

Thanks for the reply.

glad to help

So long and the short of it is that I need to find where this spur joins the ring?

If you want to add to it yes, but you must also be aware that any sockets added will require 30mA protection if this not integrated to the existing circuit, as will any newly buried cables within walls (less than 50mm without mechanical protection, ie metal conduit but not capping or you could use earth-shielded cables) But the socket requires it anyway, regardless of that.

Other than that, my only option is to plug an extension into the existing socket with a multi-socket adaptor?

It's an option, but you will be limited to the fuse rating of the extension lead, to what demand it can support.

 

[JohnW2]

So long and the short of it is that I need to find where this spur joins the ring?

Not necessarily. Provided it is not too far from where the spur cable joins the ring, what matters is that the FCU must be wired in before the first socket (not necessarily phyiscally very close to where the cable joins the ring) - if distances allow, it could be fairly close to that first socket.

Kind Regards, John

 

[PrenticeBoyofDerry]

So long and the short of it is that I need to find where this spur joins the ring?

Not necessarily

I would disagree, it is necessary to find the interconnection, as it could well be that the spur is indeed a multiple spur. So never assume, confirm!

 

[davejuk]

Yes, I'm aware of the 30mA requirement - I have a double socket with RCD built-in.

The cables will be surface mounted.

That's the solution then isn't it, to fit an FCU before the existing socket and then add my spurs.

Does it have to be a 13A fuse or can I use 20A? The ring is 32A at the CU.

 

[davejuk]

So long and the short of it is that I need to find where this spur joins the ring?

Not necessarily

I would disagree, it is necessary to find the interconnection, as it could well be that the spur is indeed a multiple spur. So never assume, confirm!

Finding the connection would mean ripping up the floor which will not be pretty. I appreciate that it's not ideal though.

The house was completely rewired in 2003. I do not believe the previous owner made any changes after the rewiring and certainly no other work was done in the loft.

 

[PrenticeBoyofDerry]

A 20A fuse, for a FCU, you ain't going to get my friend.
RCD: The solution is if you are happy with the 13A restrictions is to fit a 13A 30ma RCD protected FCU. They cost about £15-£20, cheaper than double socket plates with integrated RCD.
Or if the board can take RCBOs protect the whole circuit.

 

[PrenticeBoyofDerry]

Finding the connection would mean ripping up the floor which will not be pretty. I appreciate that it's not ideal though.

Unfortunately the connection could be anywhere, not particularly within a socket outlet could be a hidden junction/joint within the fabric of the building. The Yeehaw brigade don't care how it's done and this maybe the only solution, unless you can spur from another socket near the location or extend the circuit.
What I will add is don't go in to this naively, I would expect you or someone capable of the task to perform the correct testing procedures before commissioning any additions, alteration or extensions of circuits.

 

[JohnW2]

So long and the short of it is that I need to find where this spur joins the ring?

Not necessarily

I would disagree, it is necessary to find the interconnection, as it could well be that the spur is indeed a multiple spur. So never assume, confirm!

Yes, you're right. If there is any doubt, it is necessary to examine the interconnection, so as to ensure that it does come directly from the ring, rather than another spur. Hopwever, the OP seemed to imply that he knew that the spur came directly from the ring (maybe he installed it, or saw it being installed), in which case there would be no doubt, and need for any assuming.

Kind Regards, John

 

[davejuk]

All I can see is the single cable going into the socket. I do not know where the joint is. Lifting the floor is definitely not an option.

I do have access to the lighting ring. Would that be a better option?

 

[PrenticeBoyofDerry]

[Yes, you're right. If there is any doubt, it is necessary to examine the interconnection, so as to ensure that it does come directly from the ring, rather than another spur. Hopwever, the OP seemed to imply that he knew that the spur came directly from the ring (maybe he installed it, or saw it being installed), in which case there would be no doubt, and need for any assuming.

Bearing in mind the evidence before us your honour, I can only assume(never assume it's the golden rule) that the ops knowledge of the installation is a little shaky to say the least.

 

[JohnW2]

RCD: The solution is if you are happy with the 13A restrictions is to fit a 13A 30ma RCD protected FCU.

...provided that the new cabling isn't buried (or suitably protected). I must say that I'm a little surprised by the implication that a house re-wrired in 2003 doesn't have RCD protection of its sockets circuits, aren't you?

Kind Regards, John

 

[JohnW2]

Bearing in mind the evidence before us your honour, I can only assume(never assume it's the golden rule) that the ops knowledge of the installation is a little shaky to say the least.

In view of what the OP has said since I wrote that comment, it seems that you are right.

Kind Regards, John