One does have to, but (as I've said) we've been ignoring the VD in the final circuits (probably relatively small). Although the regs do, I agree, lack clarity, I think everyone assumes the intention is that the maximum permissible VD relates to the total VD from 'origin' (cutout/meter) to the most distant load - i.e. VD in any distribution circuits plus VD in final circuits.Don't really want to go around the houses but, with definitions being a little ambiguous. If we calculate VD from Main CU, why would we not calculate it from sub-main or beyond.
Do you seriously believe that there is any possibility that the intention of the regs is that you could have, say, 25% VD in a distribution circuit/submain and still be compliuant so long as the VD in the final circuits (beyond that distribution/submain) was within the prescribed limits? Surely not!The likely reason the discussion has arisen so often(must have missed them), as it seems ambiguous and clarification is needed.
Kind Regards, John