Quote Originally Posted by HINO
Currently the soi cannot supply 3 phase as the line down his soi is just single phase but his panel is being wired for a 3 phase split supply so when they do put 3 phase on his soi he can then get the higher supply to feed his need.
I did the same when building my house.
3-phase distribution panel with 3-phase main breaker and even put a 3-phase underground cable between house and meter.
So it was an easy job to change from 1 to 3-phase when the 3-phase line became available.

One point of caution for systems where 3-phase is used as 3 x 1-phase (ie , no true 3-phase equipment installed) :
The current flowing in the neutral line is the sum of the current in the 3 phase lines.
So the diameter of the neutral cable should be quite a bit bigger than the phase cables.