Here is a link to an Imgur album of my motor and its wiring diagram

I have a motor that I'd like to wire. My two questions are, how do I determine its operating parameters, and how do I use its wiring diagram to wire it?

My Imgur link has all the pictures I took of it, as well as descriptions of each picture. I'll still elaborate here:

It unfortunately has no ID tag on it, so I don't know what horsepower or voltage it is. The sticker on it says it is "Farm Duty", and it has a wire diagram sticker on it, so I believe I could wire it if I learned how to decipher the diagram.

It doesn't have any capacitors on it, which I think makes it 3-phase? But, the wiring diagram calls out both "low voltage" and "high voltage" configurations, which leads me to believe it is rated for 120V or 240V circuits - which is single-phase? If someone could help me understand this, that would be great!

I have general wiring skills and feel confident I could safely wire this motor with enough learning. Thanks for your help!

enter image description here enter image description here enter image description here enter image description here enter image description here


1 Answer 1


"Farm duty" motors and 9-lead motors are common in the USA. As is common with new users, you have neglected to indicate the part of the world in which the motor was found, but the label says made in USA. Since 120-volt, three phase motors are practically non-existent and 240/480 volt 3-phase, 60 Hz, 9-lead motors are quite common in the USA, I suspect that is what you have. If none of the leads are marked, you will have a really difficult time determine which leads are which, but there may be a procedure somewhere on the internet. Google "identify leads of 9-lead motor" or something like that.

To find the horsepower rating, measure the shaft diameter carefully. Also carefully measure the distance from the center of the shaft to the mounting surface. Compare those measurements with a NEMA dimension chart. The motor has a TEFC, totally enclosed fan cooled enclosure. It appears to have a "C" face. If there are threaded bolt holes on the face, that is a "C" face. You may find that there are two or more HP and RPM ratings assigned to the frame and shaft size of the motor. Getting the motor to run and determining the RPM will narrow that down. The most common RPM is near 1800, the other two common speeds are near 3600 and 1200 RPM. The full load speed will be about 2 to 4 percent below those speeds.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.