i just use the cable calculator on tlc directs website
the sizing i gave was corerct for the plan i gave (ie keep full rating to the end of the cuircuit)
Quote:I was told 2.5 SWA was good for 21amps at even 50m.
then you were told some bullshit
i put that into the cable calculator and it came out with 6mm
so your plan is an 8m 40A submain (house to garage)
followed by a 35m 16A? submain (garage to shed to greenhouse)
with this setup you should wire the 40A bit in 6mm giving a volt drop of 0.9% over that bit
and wire the 16A bit in 4mm giving a volt drop of 2.3% over that bit
this gives a total volt drop of 3.2% which is under the 4% maximum by enough to alow for volt drop in final cuircuits