Radial and RFC from 1 MCB

Looking for some info: At the moment my house has 3 radials coming out of 1 MCB. Radial 1 feeds the downstairs sockets, radial 2 feeds only 1 socket in the kitchen and radial 3 feeds the other kitchen sockets. I was talking to electrician who I had come and check and he was talking about connecting the two kitchen radials to make a ring and leaving the downstairs radial in position. So this will be 1 kitchen RFC and 1 downstairs radial feeding from 1 MCB. It sounds a bit funny to me, is there anything wrong with what this electrician is suggesting or should I get another guy in? Thanks.

There wouldn't be any radial. It would be a ring final circuit with an unused spur. Perfectly normal. 

This assumes that the unfused spur feeds only one socket-outlet. If not then the arrangement is not permitted. 

What did this electrician actually test? Did he identify that it is actually three radials, or did he not test and assume? 

There are 6 double sockets in the downstairs radial. If the electrician went ahead and turned the kitchen into a ring I understand that the downstairs sockets would now be considered an unfused spur but this is where my concern is. The 6 downstairs sockets would now be effectively a spur off a spur. Or am I just confusing myself? If it’s fine to do this I’ll trust this guy and have him do the work, thanks again

So the radial would have to be put onto its own over current protection, either by putting onto its own MCB, RCBO, Or fuse etc,

Does your fuseboard have any spare capacity?

how did said electrician suggest he was going to convert the 2 kitchen “radials “ to a ring ?

(Sharpend):

When you look at the MCB in the consumer unit, it has 3 wires coming out. When the breaker is tripped the downstairs sockets and the kitchen sockets power down. You can actually follow one of the cables out and to the single kitchen socket from my cellar. He did carry out a continuity check to the kitchen sockets by removing each line from the MCB. This is how he confirmed the 3 radials to start with. 

He was going to run a cable from the end of 1 radial to the single socket which then returns to the MCB. I don’t think there is any extra positions in the Consumer unit.

I have seen that the downstairs and kitchen sockets are RCD protected if that helps.

What size MCB is there now?

If I am reading this correctly, the result will be one ring final, and one radial, the radial having just ONE socket on it.

If so, that is allowed, the "radial" will in fact be a spur from the ring final, that just happens to connect to the origin. That is allowed for ONE socket on that spur.

You cannot then add any more sockets to the spur.

I think you’ve misread Dave? 
I understand that the said electrician is joining the existing kitchen socket to the single kitchen socket to make a ring in the kitchen and the remaining downstairs sockets will be said radial? 

That’s right the downstairs sockets would be the radial (unfused spur - once ring is made). The MCB is 32A and the wiring is 2.5mm2 which surprised me. He was wanting to add only 1 cable as the MCB and cable was already rated for a ring, instead of leaving it as a radial and upgrading all the wires to 4mm2.

The information seems to be confusing and conflicting, but you can only have ONE socket on a spur from a ring.  If the bit that will be left as a radial has more than one socket, then no that is not allowed.

The best compromise at the moment if you don't have any spare ways to split them, is replace the 32A mcb with 25A. You may not be able to get 25A for some consumer units so try 20A

Tom288 said:

That’s right the downstairs sockets would be the radial (unfused spur - once ring is made). The MCB is 32A and the wiring is 2.5mm2 which surprised me. He was wanting to add only 1 cable as the MCB and cable was already rated for a ring, instead of leaving it as a radial and upgrading all the wires to 4mm2.

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This bit seems odd to say the least.

Maybe consulting another spark would make sense

That’s what I’m thinking, The house is old and I’ve recently moved in. I wanted to have a few things checked as we are having the kitchen refurbished and the consumer unit looks ugly, no cables are labelled and it all looks pretty tight. I have a feeling the electrician was just wanting a quick fix instead of re wiring the kitchen. 
 

Murdoch: I think upgrading to 4mm2 and keeping it as a radial is because the circuit is protected by 32A circuit, that would make sense rather than leaving it with 2.5mm2 cable, I can’t think of any other reason for that suggestion. 

You do seem to be getting odd advice from your electrician.

If you are going to replace the cables with 4mm, you might as well rewire it properly as a ring on 2.5.

What type of consumer unit?  Does it have an RCD (or two)?

Older houses often were wired on radials, which is not necessarilly bad, but do need to be properly protected.  If the whole house is like this, then it is probably a candidate for a full rewire, or at least a consumer unit swap to allow you enough circuits to have all the radial circuits on their own mcb with appropriate rated MCB e.g I would keep all three radial circuits, on 3 separate 16A mcb's.