The reg No 523.8 gives the general rule as equal load sharing etc
It then says this can be acheived by either a) or b)
A/ The paralell conductors are multi core etc
B/ The minimum 50 mm for copper non sheathed etc as you state
It then says this can be acheived by either a) or b)
A/ The paralell conductors are multi core etc
B/ The minimum 50 mm for copper non sheathed etc as you state