Breaking into a ring main for an fcu and continuing

[NDavison]

I've read a number of posts some old and new but wanted to check my understanding is correct.

I have a small brick building attached to the house that is used for staorage ( a bit like an outhouse). It has a double socket already which is a spur taken from a socket in the adjoining hall. I am thinking of having some lighting to the building and perhaps an outside light added. But don't know how big of a job this is , before I get quotes of an electrician.

From what I have read is it viable to swap the double socket in the building (which is a spur from a ring) for a switched fcu which could power the lights in the builing and also then add a double socket to the switched fcu also? Could the outside lights also then be added to the switched fcu? or is this to much. From what I've read I thought so long as the first spur of a ring is an fcu then you can add to this .

 

[ban-all-sheds]

You've already got a spur from a spur, which is wrong (and unsafe), so even if you add nothing in the outhouse you need to resolve that. Which means replacing the socket in the hall with an FCU, not the one in the outbuilding.

Once you've done that you can have what you like after it, but you'll be limited to 13A.

Also, any new concealed cables or new sockets will need to be RCD protected, so if your circuit isn't already then as a minimum you should use an RCD FCU in the hall, but ideally if you're getting an electrician ask him to look at the entire installation and advise on how it should be updated.

You are not obliged to update it, but that doesn't mean it's not a BGI....

 

[DetlefSchmitz]

You've already got a spur from a spur, which is wrong

OP says it is a spur from a ring.

 

[NDavison]

Sorry if i wasn't clear, but the socket in the hall is part of the downstirs ring and the existing socket in the building is the current spur.

So if I'm understanding what your saying I can change the socket spur in the building for an fcu (so the fcu is the spur). Then connect a double socket to the fcu. But it will be limited to a 13a use. From the fcu (which is the spur) can I then add a switched fcu for lighting in the building so that effectively there will be a double socket and switched fcu connected to the fcu (spur) separately? Or would the switched fcu be connected to the double socket? How could an external light then be connected?

 

[ELZ4742]

lamens terms..

change the socket in the out building to a 13a fused spur, on the outgoing/load side of the fused spur connect your (if required) your sockets.
now, wire a 3a fused spur from the last socket and on the outgoing/load side wire your lights.

this way your sockets are fused to 13a and lights to 3a

 

[ban-all-sheds]

You've already got a spur from a spur, which is wrong

OP says it is a spur from a ring.

OK - I thought he meant the socket in the hall was a spur from a ring.

So ELZ4742 is right, but the first FCU in the outbuilding might need to be an RCD one, or any sockets it supplies might need to be RCD ones.