Identifying a radial or a ring circuit?

[EFLImpudence]

It wouldn't be undersized (if designed properly).

 

[JohnW2]

I would never occur to me to ever, ever, ever use an undersized cable for a branch on a radial.

Maybe not (and I'm not sure what you mean by 'undersized'), but it's electrically no different from doing the same with an unfused spur from a ring final - and, for what it's worth, it is one of the options shown in the infamous Appendix 15.

Kind Regards, John

 

[ban-all-sheds]

It wouldn't be undersized (if designed properly).

I believe that it would.

Maybe not (and I'm not sure what you mean by 'undersized'), but it's electrically no different from doing the same with an unfused spur from a ring final

That is true, but that has no bearing on my opinion.

and, for what it's worth, it is one of the options shown in the infamous Appendix 15.

Nor that.

A radial circuit is a radial circuit is a radial circuit.

Because of its nature, it has no end point(s), no "final" sockets.

One should always, without exception, be able to connect any number of new sockets at any point in the circuit, and one should always, without exception, do so using the same size cable as was already being used, in order to preserve the ability to always, without exception, connect any number of new sockets at any point in the circuit.

And yes, I know that not everybody takes such a sensible view, and thinks that it is OK to compromise the flexibility of future changes by using an undersized cable because it is one new socket and it is properly designed, thus deliberately creating one of the drawbacks of ring circuits by removing the ability to always, without exception, connect any number of new sockets at any point in the circuit.

But I did not consider that when I replied earlier.

 

[JohnW2]

One should always, without exception, be able to connect any number of new sockets at any point in the circuit, and one should always, without exception, do so using the same size cable as was already being used, in order to preserve the ability to always, without exception, connect any number of new sockets at any point in the circuit.

That's a perfectly reasonable personal opinion for you to have but, since it is apparent that not everyone shares that opinion, I'm not sure that your language ("one should always, without exception ...", twice) is necessarily appropriate.

Kind Regards, John

 

[ericmark]

Replace a socket with a FCU and you can then add sockets protected by the FCU it really does not matter it the socket being replaced is fused spur, unfused spur, radial, or ring final if the socket being replaced has been fitted correctly in first place there will be no problem.

 

[EFLImpudence]

Replace a socket with a FCU and you can then add sockets protected by the FCU it really does not matter it the socket being replaced is fused spur, unfused spur, radial, or ring final if the socket being replaced has been fitted correctly in first place there will be no problem.

So, back to square one.

 

[ban-all-sheds]

I just cannot see the sense in deliberately discarding one of the advantages of a radial circuit by using undersized cable on a branch.

 

[sparkwright]

To re-cap about spurring from a 32 amp 4mm2 radial circuit, there is no problem whatsoever spurring from it in 2.5mm2 cable to supply one new outlet.

As said, exactly the same as adding one 2.5 mm2 spur from a regular 2.5 mm2 32 amp ring circuit.

However, by spurring off the 4mm2 radial in 2.5 mm2 means you couldn't add to that spur in the future - so 4mm2 is definitely a better option.

 

[Fony T]

Thanks for all your replies folks, I completely forgotten that I posted this and for some for reason I haven't received any email notifications. I've asked our contractor for the certificate now, so hopefully that should answer my questions.