Extending Ring Main

[hemgrey]

To add 1 extra socket can I use 30 Amp rated Choc Block in a 47 mm deep metal box or double accessory box to make the connections This is for the kitchen, above the worktop and a junction box on the surface is not on.
Or can they be soldered and insulated with heat schrink sleeve
Also my house has 1 ring main for 135 square metres ,we have no problems but would it meet regulations

 

[1john]

easier to use crimps imo.
this work is notifiable btw, look up 'part p'
The regs state that a 30/32 amp ring final circuit should not exceed 100 sq m.

 

[STI]

To add 1 extra socket can I use 30 Amp rated Choc Block in a 47 mm deep metal box or double accessory box to make the connections This is for the kitchen, above the worktop and a junction box on the surface is not on.
Or can they be soldered and insulated with heat schrink sleeve
Also my house has 1 ring main for 135 square metres ,we have no problems but would it meet regulations

Sorry its probably me being thick, but if you can connect a choc bloc why cant you just run the wire from the existing socket to the new one, i cant see the need for a join.

 

[ColJack]

Sorry its probably me being thick, but if you can connect a choc bloc why cant you just run the wire from the existing socket to the new one, i cant see the need for a join.

really?

ok.. you have 2 cables into a socket on the ring.. you want to add 2-3 more sockets from this one.
you take out one leg and connect it to a new cable, then run this through the new sockets and back to the existing socket where it goes into the socket with the other leg of the ring..

yes you can use terminal block as long as it physically fits.. after all it's as acessible as the connections in the socket are..

 

[ColJack]

easier to use crimps imo.

obviously never tried to get a crimper into a socket backbox then?

The regs state that a 30/32 amp ring final circuit should not exceed 100 sq m.

the regs state no such thing.. they used to recomend that a ring should only serve 100m² flor space, but that has been changed to a note in the apendicies saying that "historically, a limit of 100m² has been adopted."..
it's not a hard and fast rule and the only thing that limits a ring main would be the Zs values..

 

[1john]

Nope, i tend to pull the cables out from the box, crimp on and then re dress them into the back of the box, i find that it takes up slighly less room and is not as bulky as connector blocks, some of these flush fittings font leave much room in a 25mm box.

I think using rule of thumb is best considering the OP prob doesn't own an Earth fault loop impedance tester.

 

[ColJack]

true and true.. don't know why I assumed that the legs would be cut short.. probably one too many "burnt cable cutback" repairs over the years..

the OP however does way that it's a 47mm deep backbox ( which begs the question why 47mm deep? was it once a cooker switch? )

 

[1john]

In re-reading it the OP is a little vague on the setup and exactly what is going on.

 

[riveralt]

easier to use crimps imo.

obviously never tried to get a crimper into a socket backbox then?

The regs state that a 30/32 amp ring final circuit should not exceed 100 sq m.

the regs state no such thing.. they used to recomend that a ring should only serve 100m² flor space, but that has been changed to a note in the apendicies saying that "historically, a limit of 100m² has been adopted."..
it's not a hard and fast rule and the only thing that limits a ring main would be the Zs values..

Thanks for that appendix 15 15a(iv) now amended

 

[riveralt]

To add 1 extra socket can I use 30 Amp rated Choc Block in a 47 mm deep metal box or double accessory box to make the connections This is for the kitchen, above the worktop and a junction box on the surface is not on.
Or can they be soldered and insulated with heat schrink sleeve
Also my house has 1 ring main for 135 square metres ,we have no problems but would it meet regulations

If you are only going to add one socket to the ring then just run it as a spur or for more than one run it through a fused spur.

Or are you talking about adding something other than a 13amp socket?

 

[STI]

Sorry its probably me being thick, but if you can connect a choc bloc why cant you just run the wire from the existing socket to the new one, i cant see the need for a join.

really?

ok.. you have 2 cables into a socket on the ring.. you want to add 2-3 more sockets from this one.
you take out one leg and connect it to a new cable, then run this through the new sockets and back to the existing socket where it goes into the socket with the other leg of the ring..

yes you can use terminal block as long as it physically fits.. after all it's as acessible as the connections in the socket are..

Hi Coljack,

I UnderStand that bit, the bit i found confusing was if it was only a single socket to be installed and you cold get to the cable to attach a chock bloc why couldnt it just be a spur... However thinking about it it might be a length problem and an extension needed.

 

[ColJack]

if it's a spur from the ring then just take the new cable straight to the other 2 sets of wires in the back of the socket.. no need for a connector block then.

 

[hemgrey]

Thanks Coljack
I am adding an extra 2 sockets to the ring
Is a 2 pole double socket completely independent ie giving 2 live and 2 nuetral terminals so I can extend the ring without using crimps?
Interesting info about max 100 m squared area being only a guide is this accepted in regulations

 

[1john]

The ring, is just that, a circle, you need to break the circle as mentioned above

remove one leg from the existing socket (the live neutral and earth from one cable)

Join that to a new cable which goes to the first new socket (use crimps, connector blocks or wago's)

Run a cable from the first new socket to the second new socket (terminating both cables into the actual socket)

At the second new socket run a cable back to the existing socket terminating at both positions into the actual socket front.