What is the reason for supplying 50hz to a 60hz motor? At 230V instead of 460V the only difference (AFAIK) is the current drawn, and therefor some loss in efficiency.
I found this thread: https://www.eng-tips.com/viewthread.cfm?qid=477338 where the poster asks how to use his 460v 3phase motor.
I did not see any simple answers in that thread.
Why not simply rewire the motor for 230V (it shows how right on the nameplate), then use the 220V from the generator...