Installing 3 New Sockets?

[Infoelec]

Currently I only have one double socket in my living room, I would like to add another 3 double sockets for the TV etc..

Would it be feasible just to extend the ring circuit?
Add a spur?
or do a FCU from the existing socket to the new sockets.

Thanks.

 

[PrenticeBoyofDerry]

Does the existing circuit have 30mA RCD protection? As any newly installed socket would require this, as will likely any newly buried cable within the walls.

 

[Infoelec]

Yes it has RCD protection. How would I go about adding 3 sockets?

Currently there are two wires coming out from the existing socket.

 

[PrenticeBoyofDerry]

You need to confirm the type of circuit it is, there are two main types of socket circuits.
* The ring final circuit, which will have a complete loop/ring of cables from the consumer unit through all sockets, then back to the consumer unit, this is generally run in 2.5mm2 T&E cable, on a 32A device at the consumer unit.
There will be two sets of cables (live (line), neutral, earth (CPC)), at each socket and two sets of cables at the consumer unit for this circuit, two in neutral busbar, two in earth busbar and two in the 32A MCB.

* The radial circuit, this would be one set of cable (live, neutral and earth), it is normally run in either 4.00mm2 T&E with a 32A MCB or 2.5mm2 T&E with a 20A MCB. The one set of cables will start at the consumer unit and again be routed between each socket outlet on the circuit, therefore you will have a neutral at the neutral busbar, earth at the earth buzbar and live at the 32A/20A MCB, but still have two cables at each socket outlet, until you come to the very last socket on the circuit where there will be only one set of cables, as this circuit does not return back to the consumer unit.

A few things to look at for when determining what type of circuit you have is:
Existing spurs, these can be feed via a socket outlet on the circuit, a fused connection unit or they could be hidden or accessible within the fabric of the building via junctions and jointing methods.

So to determine the circuit you have would require some investigation and some testing of the conductors, to confirm what you have.
The reason you need to confirm the type of circuit you have and if there are any existing spurs on the circuit, is that the ring final and the radial circuit are designed, installed and load shared differently.
So this would then determine how you would either extend or spur from.

//www.diynot.com/wiki/Electrics:Socket-Circuits
https://www.tlc-direct.co.uk/Book/6.3.3.htm
https://www.tlc-direct.co.uk/Book/6.3.2.htm

 

[Infoelec]

It is definately a ring final circuit. Which I have have found out when I did the bedrooms sockets.[/url]

 

[PrenticeBoyofDerry]

And how did you confirm this? The number of times people have told me that a circuit is an RFC and turned out to be a radial.......

The only way you can tell is by either revealing the whole circuit so it can be visually walked/seen or by testing the circuit out. Unless you installed it that is!

 

[Infoelec]

I have seen most of the circuit during works when builders redid my floor. it is definitely a ring, electrician confirmed this

 

[PrenticeBoyofDerry]

How would I go about adding 3 sockets?

Currently there are two wires coming out from the existing socket.

There are a few different ways, I prefer to avoid junction/joints within the floor void. So tend replace at least one cable for new.
There is a rather coarse method shown in Wiki. But give you an idea of what is required.
//www.diynot.com/wiki/Electrics:Extend_Ring

If it is not possible to avoid junctions/joints within inaccessible locations, then use a Maintenance Free junction box (BS5733-MF)
http://www.tlc-direct.co.uk/Products/ASJ803.html?source=adwords&kw=&gclid=CJeD9prp970CFZDKtAodFS4AKA to make the connections.
I suggest prior to extending the circuit you do a at least a Zs test to confirm the circuits Zs is okay, then once you have extended the circuit run do the required dead test prior to energising and then the required live tests prior to commissioning.

 

[Infoelec]

Thanks for the solution, I appreciate it

 

[ericmark]

If you want to extend the ring you need to separate out the two feeds to the existing socket. Since it is a double socket the easy way is to replace it with a pair of grid sockets.

These sockets clip into a Face plate you then have two single sockets in the space taken by a standard double socket so as long as the back box is deep enough to can fit the two cables required to extend the ring.

Or you could use a Fuse and a blank to form a single socket and a fused spur from the old double socket.

But it is really important to test that the ring is not compromised during the work.

 

[ban-all-sheds]

I have seen most of the circuit during works when builders redid my floor. it is definitely a ring, electrician confirmed this

But rings can have spurs from them and sometimes people spur more than 1 socket.

Knowing that the circuit is a ring, and seeing a socket with 2 cables isn't enough - you need to confirm that the socket is on the ring.