3 Phase Induction Motors û Single Phasing Question

[Barryng]

I am familiar with the characteristics of a running three phase induction motor under an abnormal single phase condition. I am looking for information concerning the starting characteristics of a three phase induction motor if it is single phased on a start attempt. Will it start and accelerate if the shaft is initially at zero rpm? If there is some minimal rotation existing when energized, will it accelerate? I am more interested in the mechanical characteristics of the behavior of the motor than I am with the electrical parameters.

 

[electricpete]

If speed is zero the problem is just like single-phase motor without an auxiliary winding... there is a force back and forth but not a torque.

If speed is above zero you might have a prayer of providing some torque to accelerate the motor somewhat. There are no guarantees that you will have enough torque to make it to full speed rapidly without encountering your trip or thermal limits.

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