Understanding AC Motor Basics: Why a 120V Motor Can't be 3-Phase

[Soleste23]

TL;DR Summary

I have never seen a 120 volt three phase motor.

I have just started my electrician career and I am studying electric motors. why an 120v ac motor can not be 3 phase ? .

 

[Averagesupernova]

Summary: I have never seen a 120 volt three phase motor.

I have just started my electrician career and I am studying electric motors. why an 120v ac motor can not be 3 phase ? .

Are you aware of any 3 phase power sources that are 120 volts leg to leg?

 

[Dullard]

There's no physical reason that a 3-phase motor can't be 120 Volt, but it would require a 3-Phase 120 VAC supply (which is not a standard anywhere that I know of). In the US, the lowest common 3-Phase voltage is 208 VAC - that's 208 VAC L-L and 120 VAC L-N.

 

[berkeman]

https://www.plugsocketmuseum.nl/ThreePhaseTransformers.html

 

[Averagesupernova]

Something to think about: A VFD driving a three phase motor would output 120 volts at about half speed in order to keep the frequency to voltage ratio correct.