Controling speed of electric motor

Thread Starter

bob232

Joined May 14, 2019
2
I have a 5hp erlectric motor from an Air Compressor I installed on a metal Lathe. The only information I have on the motor is it has 2 external capacitors, is 120V 15.0 Amps 60 HZ 1PH. Is there a way I can control the speed of the motor without causing damage to it?
 

MaxHeadRoom

Joined Jul 18, 2013
19,197
Sounds like an induction motor, c/w start and run caps, the only way to vary speed is with frequency, but the results are dismal for this type and size of motor.
Most go with a 3ph motor and a 1ph 240v VFD, or an ex-Treadmill DC motor and controller.
Max.
 

ian field

Joined Oct 27, 2012
6,539
I have a 5hp erlectric motor from an Air Compressor I installed on a metal Lathe. The only information I have on the motor is it has 2 external capacitors, is 120V 15.0 Amps 60 HZ 1PH. Is there a way I can control the speed of the motor without causing damage to it?
EPE magazine did a pool pump motor project a few months ago that allegedly addresses some of the issues with this type of motor. I still think it looks a right PITA - YMMV. Recent name change back to Practical Electronics just in case Google gets confused.
 

MaxHeadRoom

Joined Jul 18, 2013
19,197
You can bet that if these motors ran on some kind of 1ph VFD, there would be all kinds of them coming out of China, as there is with the 3ph versions.;)
Max.
 
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