Single Phase motor design

[pitlessunit]

Can anyone explain the difference in design of a capacitor start and a PSC motor.

I know the difference with the switch and start capacitor on the capacitor start and the run capacitor always inline on the PSC.

We were working with a single phase drive on a PSC motor when the voltage was taken down to zero on the auxilary winding the motor amperage when above the SF amp rating of the motor.

Is there a major difference in design of the cap start and PSC motors and can you explain the differences?

 

[Marke]

Hello pitlessunit

Basically, if you have a switched start capacitor, you will have a much higher start torque than if you have a permanent split capacitor.

One advantage of the PSC motor is that it does not have a mechanical (or electronic) switch to disconnect the capacitor, so less filed problems.

For more information, see

http://www.iprocessmart.com/leeson/leeson_singlephase_article.htm

Best regards,
Mark.

Mark Empson
L M Photonics Ltd

 

[pitlessunit]

Thanks for the link. I have a basic understanding as shown in the link.

My question was how is the internal design different?

A capacitor start motor uses the start capacitor to start the motor and then switchs out of the ciruit. With PSC motor the capacitor starts the motor and stays in the circuit. PSC motor can have a start capacitor added for hard starting. This capacitor switchs out and the run winding stays connected.

How do the motors differ internally?

Thank you