Sorry Electro. We (or at least I) were/was just mocking our/we`re selves. The cooker question has been done quite a bit this week.
Back to your point....
As said, even with a outlet attached, when diversity`s applied the Ib (design current is genuinely and fairly assessed to be no greater than 24 amps.
So, as our In (rating of protective device) = or > than Ib the next common size would be Lenny`s 30A breaker (he should really have said 32A but he still thinks 3036s are new
)
So Iz must be equal to or greater than In, so we`re looking for a cable (lets assume T&E is appropriate) so a 4mm would be ok in theory if a short, perfect run. As you must always check for VD
you might even find the roughly...hmm...32 metres allowable for 4mm is too short.
But realistically, the run may not be wonderful old clipped direct C, so any factor applicable might well force you upto 6mm (very likely)
In the most onerous conditions, 10mm may well be needed - even if only to get you to sleep at night
Or if your running thru a foundy
But, seriously, if you apply the rules allowable you WILL come out with an appropriate cable size - and not an over engineered snake due to fear of the unknown.
Hope that does clarify it a little for you. If you want to know a little more on the subject of design etc - then i can recommend various references mate
& sorry for being silly before