Spurring Socket To The Shed

[gocsan]

Hi guys

I've recently added double socket spur from my living room into the conservatory (left socket from the conservatory in the diagram). While taking the face plate off from socket located at the top left of my living room (see diagram), I've realised that the electricity from my shed is spurred from this socket. Seeing that you can only have one spur from socket from the ring main, I decided to remove the shed connection because I woud rather have a socket at the left side of my conservatory and ditching the electricity to my shed. The cable for the shed is disconnected but buried into the plaster of my wall near the socket that it was originally connected to.

It didn't occur to me that I could have cut the wire from the ring main to add a junction box and have the shed socket spurring off the junction box instead. So effectively, I get to have both working sockets in the conservatory and the shed. As I haven't installed floorboards in my living room, it's not too late for me to change my mind, but wanted to ask for some advice.

The 15 metre cable for the shed was already in place when I've purchased the property, but I know it doesn't mean that it's safe or whether it adheres to regulations. So my question is, is there a regulation that limits the cable length of a spur? The shed cable is about 15 metres. Also can I do this work myself without notifying building control or without the need for a qualified electrician to do the work?

Thanks

Sorry, let me correct myself. The shed cable from the living room end is only long enough to reconnect it back to the original socket it was connected to. So if I were to have a working conservatory socket, I'm going to have to get a longer twin and earth and connect this socket to the junction box instead.

 

[Technician]

There is no regulation that sets a maximum length of the run of

conductor in a spur, however, if the spur length is excessive, the

disconnection time for the protective device that protects that

circuit may be compromised.  This can only be ascertained by

testing.

If you post some information about the conductor types, circuit

breaker size and type, some of the others might be able to assist.

Your sketch shows the conservatory sockets as spurs off the

living room ring main. Is that the case?

 

[gocsan]

Thanks for the response Technician. I'll have to check the details later. But yes, the conservatory sockets are spurs from the living room main.

I'm not sure really sure about the conductor type of the cable, but it looks like a really thick steel armour cable if that help :S

Actually I have a diagram. The yellow, red and blue wire sticking out underneath is the 15m cable to the shed.

 

[Technician]

I suspected that so...there will be plenty of advice about what to do.

First thing they need to know is if it is buried, is the armouring used

as a protective conductor and all that sort of thing.  I am sure if you

ask a forum member will come out to you who is close.

LOOKS like the protective conductor is not the armouring.  Do you

know how old the shed is because those are the old colours which

you will know anyway.

 

[ProDave]

Question 1: Is there an RCD feeding the ring circuit?

What I would so is fit a switched fused connection unit (FCU) next to the living room socket, making the feed into the FCU part of the ring.

So you can then spur from the existing socket to the socket in the conservatory, and the FCU will then feed to the shed giving you the advantage of a fuse and a switch for the shed.

If the answer to question 1 is yes there is an RCD then fit a normal FCU, but if you don't have an RCD feeding the sockets already, then fit an RCD FCU for the shed (that would also raise the question of RCD protection for the conservatory socket if that was the case)

 

[gocsan]

Yes, there is RCD feeding the ring circuit.

Even if I put an FCU next to the double socket in the living, the yellow, blue, red cable in the image above may be too short to pull over into the FCU. I can probably convert this existing double socket into an FCU and add a new double socket next to this?

Before we go any further, I'm not an electrician but I do feel comfortable with doing this by myself. Can I legally do this work on my own without notifying building control? If not, then I might as well get an electrician in in order to get the installation certification.

 

[gocsan]

Hi ProDave, I've just thought of something better, since the distance of the double socket in the conservatory is not too far off, I can make this double socket part of the ring rather than having it as a spur. So with your suggestion above, I'll have a cable connecting to the FCU -> connecting to double socket in the conservatory -> connecting to double socket back in the living room. So the only spur I will have is from the FCU to the shed.

So is this work notifiable?

 

[NozSpark]

There looks to be a disparity between your drawn picture and your photo..... there looks to be two cables entering the socket, so it is either already part of the ring or it has another, something, spurred of it (naughty) 

 

[gocsan]

There looks to be a disparity between your drawn picture and your photo..... there looks to be two cables entering the socket, so it is either already part of the ring or it has another, something, spurred of it (naughty)

The two cables entering from the bottom is definitely part of the ring

 

[NozSpark]

The two cables entering from the bottom is definitely part of the ring

So....

The photo that you posted,,, is that a picture of the socket in the conservatory or the living room??

 

[gocsan]

So....

The photo that you posted,,, is that a picture of the socket in the conservatory or the living room??

The photo is a socket in the living room. So in the drawn picture, that would be the top left hand side within the living room.

 

[gocsan]

Ok guys, I've redrawn my diagram focusing on the area where I'll be working on and I've deliberately drawn the walls thicker to highlight my wiring intentions. So basically I'm going to have the conservatory double socket as part of the ring instead of spurring it off from the double socket in the living room. I'll have a 13A FCU in place right next to the socket in the living room and my shed cable will spur off from the FCU.

 

[NozSpark]

TBH it looks like some of your cables might be out of the approved zones :|

 

[gocsan]

TBH it looks like some of your cables might be out of the approved zones :|

I'm not quite sure what do you mean. Are you saying that in order for this to comply with regulations I'll have to replace the entire shed cable?

 

[NozSpark]

Well, there are certain places that we are allowed to install buried cables.... directly on a horizontal or vertical plane with an accessory, within 150mm of an internal corner formed by 2 walls and within 150mm of the junction of a wall and ceiling