split phase is mainly used where three phase isn't practical (usually due to only wanting to run two HV wires rather than 3) but you wan't quite a lot of power.
its much easier to make a cable with 3 active conductors of which any single conductor will have a max of say 200A and a maximum total of 400A than a cable with two active conductors capable of carrying 400A each.
its much easier to make a cable with 3 active conductors of which any single conductor will have a max of say 200A and a maximum total of 400A than a cable with two active conductors capable of carrying 400A each.