RPC's generate a third phase from the product of the two 1 phase lines fed to the motor, the voltage is stabilized as best as possible using capacitors connected from the third phase to each of the 1ph lines, Generally the 3rd phase is higher initially to counteract the variation that is going to occur between the 1ph pair and the 3rd line when you put a load on them.
It depends on how well the tuning as to how close the voltage is going to remain on the 3rd phase with varying load span.
If the 3ph on the machine is for 3ph motors only, then there is not usually a problem, if you have control power on the machine that is fed from a single phase transformer in the enclosure, make sure that the 240v 1ph lines that are passed straight through from the RPC are feeding this 1ph transformer and not fed by the 3rd phase for stability purposes.
Al.
CNC, Mechatronics Integration and Custom Machine Design
“Logic will get you from A to B. Imagination will take you everywhere.”
Albert E.