I use this method to test three phase motors because plugging a faulty motor into an inverter will blow it up.

the problem with this is getting the motor started. if the motor is vertical with no load it will start, if the motor horizontal with no load some may start but most unlikely without giving it a spin. if the motor is under load you will have to get it up to speed to get it to run. this is not something new this has been known for years, if it worked properly I for one would not have wasted money buying inverters.

A 3 phase motor running on single phase with the help of a capacitor has a poor starting torque and may need a little nudge to show it what is required of it but if the driven machine has a clutch this is not a such a problem as it doesn't have to be started so often although it may still need that slight nudge . A clutch could be something as simple as a slackening drive belt .Interestingly, a friend of mine used a small single phase motor in the manner of a car starter as the 3phase motor doesn't have to reach anything like full speed to develop enough torque. He also used a small motor to start a large single phase motor that would otherwise draw too much starting current! Colin