Does a system need to be extended throughout the entire building? for example, three phase 4w 240 Volt, Feeder just for 3 phase load, Do you carry the neutral even if it isn't used?
It depends on how forward-thinking you want to be. You didn't give enough information for a better answer. It's cheaper to install a little extra now, than re-do the work later. What if you need to install some control circuits?
