Extending the ring main

[onionsa]

Due to the position of the existing sockets in the room, extending from one is about the best option. So should I look at 2x 30amp junction boxes sunk in the wall for this?

 

[EFLImpudence]

If you are extending from one existing socket, then you only need to

Remove one existing cable from the socket,
Replace with first new cable,
Join removed existing cable to second new cable with connector blocks.

 

[ericmark]

1) Test it is a ring.
2) Test the loop impedance and see if extra cable can be added.

Easy way I have used is replace a double socket with two singles. Using grid sockets you can do that still using a double back box.

Removing a section out of an existing ring and replacing it with a longer section with extra sockets does need some careful testing.

Fig of 8 may not be against the rules but should be avoided if you can to ensure it does not overload any leg.

 

[onionsa]

If you are extending from one existing socket, then you only need to

Remove one existing cable from the socket,
Replace with first new cable,
Join removed existing cable to second new cable with connector blocks.

Would this be a suitable connector? https://www.tlc-direct.co.uk/Products/DEBOX2.html

1) Test it is a ring.
2) Test the loop impedance and see if extra cable can be added.

Easy way I have used is replace a double socket with two singles. Using grid sockets you can do that still using a double back box.

Removing a section out of an existing ring and replacing it with a longer section with extra sockets does need some careful testing.

Fig of 8 may not be against the rules but should be avoided if you can to ensure it does not overload any leg.

Thanks for your input ericmark, does the illustration posted above constitute a Fig 8?

Thanks.

 

[ban-all-sheds]

Is there room inside the back box for three of these?

 

[JohnW2]

Is there room inside the back box for three of these?....

That would presumably depend a lot on how big "one of those" is?

Kind Regards, John

 

[EFLImpudence]

Here's a smaller one -

 

[ban-all-sheds]

That would presumably depend a lot on how big "one of those" is?

This gives a clue:

 

[ericmark]

No what is shown is not a fig 8. But it shows one end of the editional wiring going else where so it could result in fig 8. If coming from a double socket easy way is replace it with a LAP 4 way grid plate and two grid sockets, this splits the ring into two halves and gives you the two sets of terminals to connect the new part of the ring.

However testing is required. Of couse all should be tested but if using a FCU then the chance that the ELI or volt drop are exceeded is much reduced.

Remember ELI and volt drop should be tested centre of ring final if using a loop impedance meter which may not be where the extra sockets are. Or you go into the consumer unit to test with a low ohm meter which must use at least 250 mA so not a multimeter.

It is not simply add cable, with extending a ring. With a FCU the limits are for 13A not 32A so it is unlikely they are exceeded.

 

[JohnW2]

No what is shown is not a fig 8. But it shows one end of the editional wiring going else where so it could result in fig 8.

Indeed, but if the only thing(s) connected to that 'end' (pair of 'ends') is/are new sockets, then there would be no risk of creating a "figure of 8" circuit. That could only happen if one established a connection between those 'ends' and some other part of the existing ring, and I struggle to think of why someone would do that.

Kind Regards, John

 

[onionsa]

If there isn't room for those connectors, I could always sink a deeper box. These seem like a pretty simple solution to what I'm after.

 

[ban-all-sheds]

What about a figure of 8 just for the extension part of the cpc?

If those push-in splices were used to join L&N, the use of a 3rd could be avoided by joining the cpcs at the socket or back box earth terminal.

Non-compliant, but.....

 

[JohnW2]

If those push-in splices were used to join L&N ....

"Joining L and N" is not a very advisable practice

Kind Regards, John

 

[onionsa]

"Joining L and N" is not a very advisable practice

Kind Regards, John

Noted...

 

[mwatsonxx]

If those push-in splices were used to join L&N

You're not very good at this, are you?