Breaking into 16a Radial Circuit

[BillyWillySilly]

I've laid cable for an extension to a ring circuit, but am rethinking where I break in. This ring carries nearly all of the sockets in the upstairs of the house. I have a 16A breaker in the consumer unit that is currently feeding 3 sockets to a small porch area that is a radial. I'm thinking of using this instead for the new sockets.

I have full access to the radial cable, and the new sockets, in an adjacent room will be fed under upstairs floor boards (around 8 or 9m away). The new sockets are all connected but not live, with two tails. Originally, I was going to extend the ring but if I use this radial circuit instead can I just extend the new tails to the 16a cable and wire in serial ie extending the radial as is:
1. Snip Porch tail
2. Connect each new extension tail to either end of the 16a

Or is it allowed to just connect one of these new tails from the existing 16a cable, and then I terminate the resulting tail?

Other things to note: previous electrician put a 13a fused spur before the porch sockets. There is no return to the consumer unit so this is a radial, but I would be break in prior to this. Not sure why the 13a fuse was put in.

The new sockets are driving a TV, fridge and lamps etc. All cabling is 2.5mm2 and there are 7 new double sockets in total.

 

[EFLImpudence]

What do you mean by 'tail'?

 

[BillyWillySilly]

Sorry, ends of the cables

 

[EFLImpudence]

if I use this radial circuit instead can I just extend the new tails to the 16a cable and wire in serial ie extending the radial as is:

Ok, if you do that you would only need to connect one of the 'tails' to one of the sockets on the radial - disconnect the other 'tail' from the farthest of your new sockets - in parallel; not series.

Or is it allowed to just connect one of these new tails from the existing 16a cable,

Yes.

and then I terminate the resulting tail?

As above; disconnect it.

Other things to note: previous electrician put a 13a fused spur before the porch sockets. There is no return to the consumer unit so this is a radial, but I would be break in prior to this. Not sure why the 13a fuse was put in.

There is no need for the 13A fuse on a 16A circuit.

The new sockets are driving a TV, fridge and lamps etc. All cabling is 2.5mm2 and there are 7 new double sockets in total.

Ok.

 

[Adam_151]

Perhaps the plan was to connect in as a spur from the orgin of the ring circuit, but instead a spare 16A breaker was found when the cable was got into the board

 

[BillyWillySilly]

To be fair, I think originally he thought it was on a spur. We had some interesting discussions as we have 7 consumer units. Some of them have breakers that only support 3 or 4 sockets. We got past the point of getting things so that they made sense that a rewire was no longer feasible - but in hindsight we should have done that in the first instance.

The porch area had no sockets working so a new cable was run or replaced from the board. I cannot quote remember the order of events though.

 

[winston1]

We had some interesting discussions as we have 7 consumer units.

Must be a typo. How many?

 

[BillyWillySilly]

Must be a typo. How many?

Nope. 7. 2 of which in bathrooms.

All that's been rectified now - more or less. One that we had in the bathroom had 4 breakers, 1 each for a 3 pin socket (yes, in a bathroom), light, shaver socket and mirror light. It appears that the previous owner would install a new mcb and run a thick cable to a room, install a CU then circuit off of that. Did a lot of tinkering. I'm pretty capable but haven't ventured into the consumer units themselves.

Hindsight is great, we should have ripped everything out but the electrician only told us that after we had half the house replastered. He didn't come back afterwards.

 

[plugwash]

I wonder if he was an industrial electrian of some sort, in certain industrial environments, especially where kit changes often it can be sensible to have a local distribution board in each room, then when needs change you only need to re-work the stuff in that room and can avoid disrupting anything else.

 

[BillyWillySilly]

I wonder if he was an industrial electrian of some sort, in certain industrial environments, especially where kit changes often it can be sensible to have a local distribution board in each room, then when needs change you only need to re-work the stuff in that room and can avoid disrupting anything else.

It's interesting you say that. He was a lecturer of some sort of engineering.

 

[sparkwright]

It's interesting you say that. He was a lecturer of some sort of engineering.

Aren't they always...?

 

[BillyWillySilly]

Thanks for the advice. All wired in and working well.