hi all,would like to split 1 phase (off 3 phase supply big house)after the meter into a henley block and run to a new 100/80 amp isolator(inside meter box) to a new flat(in grounds approx 10 m away.Going to run supply in 25mm swa glanded at each end to new cu.have looked at balance of phases in house pretty much the same.Does this sound ok or am i missing some factors.your opinions much appreciated. ta