The 310 has no spindle drive, the hole in the panel for spindle was only for J325/J425 machines that had a VFD for spindle control. The control and drives are single phase, and I don't think the 310's came with a coolant pump which was 3 phase.
I would get a 3-4hp VFD and wire the spindle motor to that, and use single phase for the rest of the machine, or just use it as a phase converter.