Andy Wade coughed up some electrons that declared:

Tim S wrote:

Lecturers sometimes have their own slant on things and it may or may not
align with reality :-

Quite. AFAIK there's no intention whatever to abandon the faithful ring
circuit, but there is something of a campaign going on to educate
electricians about the radial alternatives. Hence Appendix 15 in the
New Red Book.

Next step: Can you construct a 32A radial circuit using 13A sockets?

Yes, of course - it's one of the standard circuits: 4 mm^2 cable for the
main circuit, spurs in 2.5 subject to the same rules as for rings,
max. floor area served 75 m^2.


Thanks Andy - it was really for Mickey. Anyway, I'll follow through on the
thought I was hoping to provoke:

Assuming I'm reading Table 4D2A (IEE regs, 17th) correctly, 4mm2 cable
derates to 25A capacity in thermal insulation and 30A in conduit in wall,
so quickly becomes unsuitable for a 32A radial circuit.

A BS1363 socket has a stated terminal capacity of 3 x 2.5mm2, or 2 x 4mm2
conductors per terminal, with occasionally a manufacturer allowing 1 x
6mm2.

So, my argument to Mickey and his lecturer:

Suppporting a 32A radial circuit in practise is difficult.
A 20A radial is easy enough, but personally, I find them conceptually less
useful for general purpose use, where loading is unpredictable and the
possibility of wanting a load 20A on a particular circuit is quite
likely.

Ergo, I don't think radials are the way to go, except in limited cases where
20A is known to be adequate.

Cheers

Tim