There is only one ground wire needed on any motor, single or three phase.
For a 240-volt single-phase induction motor, a two-pole motor starter is typically required, as it connects to the two live conductors of the single-phase supply. For a 440-volt three-phase induction motor, a three-pole motor starter is needed, as it connects to the three phases of the three-phase supply.
Infinity
You still need the same horsepower. The advantage of the three-phase motor is that it will draw lower current.
To answer this question the voltage of the motor is needed.
Single phase motor winding is often checked just by listening to the noise that the motor is making. An experienced person can tell if the motor is working at single phase or double phase.
single phase fully control converter
Check the motor's terminal box. If there are three service input cables - such as red, yellow and blue - plus an earth wire, then it is a three phase motor. If there are only two wires plus an earth wire, then it is single phase.
Any single-phase a.c. generator producing more than 2.5 HP or 2 kW - at the required voltage.
No. That would be a single phase motor.
To use a single/one phase motor instead of a three phase motor is possible if you have a three phase power supply as you will only need to tap one of the three phases together with neutral and an earthwire, however to use a three phase motor instead of a single phase will require the provision of three phase power supply.
The difference between a single phase and a three phase motor is the amount of power conductors that feed the device. As to the other part of the question a three phase motor will not start or run on single phase. The phase angles on three phase are 120 degrees apart on a single phase system they are 180 degrees apart.
The motor cannot be altered to work on single phase power. You will either have to put in a new single phase motor or use a phase convertor box. Do a google search for phase convertor - you will find plenty.