How big is a generator that can drive three 2.2 kW electric motors?

If your motor is soft-start, a generator capacity of 2.2 kW is sufficient. Since the motor starting current is (4-7) times the operating current, if it is started directly, the following conditions must be met: 1. There is an independent transformer and it is not started frequently. The engine capacity cannot exceed. 30% of the transformer capacity. This means you need a motor greater than 7 kW. 2. If there is an independent transformer and it starts frequently, the motor capacity cannot exceed 20% of the transformer capacity. This means you need a motor greater than 11 kW. 3. Without an independent transformer, the voltage drop caused by motor starting cannot exceed 5% of the transformer capacity. To give you a formula, the starting current divided by the operating current is not greater than thetransformer capacity divided by motor power plus 3 divided by 4.