Single wall socket connected to two Mini Circuit Breakers.

[Taylortwocities]

Maybe my brain not working, but how would those tests show an interconnected ring?

At the time of installation it would have proved that wires 1&2 were the ends of ring 1. And that wires 3&4 were the ends of ring 2. He may have done this test but he mixed them up when he fitted the ends to the MCBs.
It doesn’t reveal an interconnected ring later on.

 

[Taylortwocities]

TTC - is it acceptable to have a radial single socket connected to a 32A MCB wired in 2.5mm as it appears to have been done?

Yes, it is. It’s a spur, same as any other. Except the connection has been made at the MCB not at a socket. Perfectly normal.

But, like any spur, you can only have one socket, not two or three on the one spur.

 

[EFLImpudence]

My above concern is a 2.5mm cable protected by a 32A MCB (27A CCC)?
Edit: which (now I've thought about it) is ok isn't it?!

Yes, it is protected by the fuses in the plugs - 2 x 13A = 26A - which is why only one double socket is allowed on the unfused spur.

Just to confuse matters, although two single sockets would be the same, some say certain words in the regulations prohibit two singles.
Electrically it would be fine.

You can always use 4mm² cable for the unfused spur then have more sockets.

 

[gman76]

Yes, it is. It’s a spur, same as any other.

Of course - thanks TTC. Bit of a brain fart this evening! Not being an electrician, I don't live & breath this stuff every day!
Thanks for clearing that up.
Luckily, I don't think the OP wants to spur from the added socket, so FCU issue averted.
Thanks too to EFLI.

 

[Daniel Keenan]

You haven’t created any mess. You what should be two ring final circuits, one has a spur from it. That is the socket in the garage (see below on this*).
Due to a error at some point, the two rings have become connected together, they should be separate. There’s probably a simple reason and a simple solution. an electrician can sort this easily.

HOWEVER, If the existing socket is a spur from one of the rings, then you cannot just add another socket to it. It needs an FCU to be fitted first.

I suggest you get an electrician to sort your interconnected ring problem and have them sort the additional socket at the same time.

Thanks TCC, I understand all of this. I just want to add another socket directly to the ring from a socket that is not from a spur but was originally built with the house. That's perfectly fine isn't it?.

 

[Daniel Keenan]

Yes, it is protected by the fuses in the plugs - 2 x 13A = 26A - which is why only one double socket is allowed on the unfused spur.

Just to confuse matters, although two single sockets would be the same, some say certain words in the regulations prohibit two singles.
Electrically it would be fine.

You can always use 4mm² cable for the unfused spur then have more sockets.

Can you add 4mm² cable to an already existing 2.5mm² final ring circuit? Does this not overload the 2.5mm² or does the circuit compensate by distributing the load evenly on both sides of the spur (which are using the 2.5mm²)?

 

[Taylortwocities]

Thanks TCC, I understand all of this. I just want to add another socket directly to the ring from a socket that is not from a spur but was originally built with the house. That's perfectly fine isn't it?.

Yes, if it is on the ring itself and not already a spur.

 

[Taylortwocities]

You can always use 4mm² cable for the unfused spur then have more sockets.

Really? I don’t think so.

 

[EFLImpudence]

Can you add 4mm² cable to an already existing 2.5mm² final ring circuit?

Yes.

Does this not overload the 2.5mm²

No. Not per se.

or does the circuit compensate by distributing the load evenly on both sides of the spur (which are using the 2.5mm²)?

Only evenly if in the centre of the ring - but
27A is so near 32A that enough to overload it would have to be very near one end.

Plus, of course, there could be two or more 2.5mm² spurs close together so the fact that one might be 4mm² does not raise any separate concerns.

 

[Taylortwocities]

Have I misunderstood this

You can always use 4mm² cable for the unfused spur then have more sockets.

To me, this says that (in your opinion) you can connect a bit of 4mm² cable as a spur to a 32A protected 2.5mm² ring final. then string 5 double 13A sockets on the end of the 4mm² Cable??

Is that what you mean?

 

[EFLImpudence]

Yes, with the already mentioned proviso that it is not too near one end that it would cause a problem - as would 5 separate spurs.

 

[Taylortwocities]

Not according to app 15. If what you have stated is allowed then we can all connect 4mm SWA to ring finals, run it down our gardens and put consumer units on the end.

 

[EFLImpudence]

Appendix 15 is only informative and not exhaustive.

If 32A is enough for the garden circuit, then why not? Why would you mention a consumer unit?

 

[EFLImpudence]

Tell us why Appendix 15 apparently 'prohibits' two single sockets on a 2.5mm² unfused spur.

 

[sparkwright]

Have I misunderstood this

To me, this says that (in your opinion) you can connect a bit of 4mm² cable as a spur to a 32A protected 2.5mm² ring final. then string 5 double 13A sockets on the end of the 4mm² Cable??

Is that what you mean?

This is fine, if the 4mm2 is connected to a socket or joint DIRECTLY on the ring (ie not a spur), and the cable to the new 5 sockets would have to be in 4mm2 (though the very last one could be 2.5mm2.

I also don't see a problem spurring in 4mm2, then forming an additional little ring from there onwards in 2.5mm2.


Not that I would do much of this in reality - makes the testing a pain for a start.