You MAY be able to still use the power supply at 80 v IF the transformer is dual wired for 240/480 volts. IF yo wire it for 480 and apply 240 you end up with 80v instead of 160v.
Even then the size drives you are needing to properly drive the motor you have are EXpensive . Might be cheaper in the long run to source out a used set of Haas drives or rebuilt exchange drives.
Just a thought, (;-) TP