Can you convert a three-phase motor to a single-phase motor?

Answer 1

Use only one of the legs (L1-L3), and the neutral. Some three phase circuits don't have a neutral. If that is the case, then you cannot run single phase.

Comment

You don't need a neutral, providing the voltage is appropriate, you can get a single-phase supply by connecting the load between any two lines.

Answer 2

There are three ways to do this typically. (besides replacing the motor).

There are static converters which have no moving parts but you lose some power and starting torque.

There are rotary converters which require a single phase motor to turn a three phase motor which acts as a generator to drive the three phase motor of the device you want to power. This of course ends up with three motors including the one you have to begin with, but it works well.

THe third and best solution is an electronic three phase source. It works off your single phase and generates DC. The DC then powers a special three phase inverter synthesizing three AC waveforms 120 degrees out of phase which powers your motor. The best ones allow changing the frequency which will make it a variable speed controller and also allow reversing the phase rotation to run the motor bidirectionally. These are fairly compact and can be quite versatile and not terribly expensive - that would be my first choice.

Answer 3

No, because the three phase drive is always monitoring the three phase output for line loss. If one phase is missing the drive will shut down with a phase loss alarm.