Here's a quick one for you 16th edition guru's:
I need to run 75% of the cables from my consumer unit together in a
bundle for approx 1 meter, (as far as I can see I have no other
practical physical choice for the routing).
I'll need to derate the cables, which will mean I'll need a larger
cable for my rings, (I'll do the full calculation later, but suffice
to say it's going to be larger than 2.5mm^2)
The question is; is it acceptable to use the larger cable just for the
legs from the CU to the first/last socket, (i.e. through the 'grouped'
section), and then wire the rest of the ring in 2.5mm^2 ? [after of
course checking on other derating issues for the rest of the circuit
etc etc etc etc etc]