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AC Motor Wiring ? 2

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Trigonatus

Computer
Jun 6, 2017
4
I've made several attempts at wiring this small AC motor but can't seem to get it to work. I'm sure the answer is right in front of me but I'm not sure how to interpret the schematic. Any assistance would be appreciated.

Thank you.
 
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It looks like a 2-speed motor, with connection to either white & black for high speed, or white & yellow for low speed.

There should be a 20uF capacitor with the motor, typically a plastic or aluminium can about 1.5" diameter and maybe 4" long. That's 'C' on the diagram, connect it to the red and orange leads.

There's a thermal overload which looks like it is a self-resetting Klixon type. Your should be able to verify continuity between the white and red leads to prove it is OK.

 
Thank you, Scotty. Would the motor work if the capacitor were omitted and the orange and red leads were simply connected? Or is the cap needed as a "start-up capacitor"?

Thanks again.
 
You need the Cap.
It should be rated for continuous duty, not a starting capacitor.

Bill
--------------------
"Why not the best?"
Jimmy Carter
 
Bill, Thanks for the information.
After some research, I believe the capacitor causes a 90-degree phase shift which determines the rotation direction of the motor. Moving the capacitor to the other winding should reverse the rotation direction. Is my understanding correct?
 
With the connections available to you I don't think you can reverse this one electrically, although I could be wrong. You would need to reverse the polarity of either the start winding or the main winding, and the winding ends aren't brought out - there's an inaccessible connection brought out on a single black wire.

A trick I've used on very small shaded pole motors - which are inherently non-reversible - is to dismantle the motor and physically reverse the rotor so that the shaft is at the other end, assuming the bearings and end-bells allow you to do this. You may have the option here, and I think it should be simple enough on this motor because it looks like a permanent split capacitor motor rather than a cap start, induction run type. The latter can be fiddly because of an internal shaft-mounted switch which disconnects the start winding once the motor is at running speed, but I don't think that's what you have here.
 
In most permanent split capacitor motors one winding is designed to run in series with a capacitor and the other winding is designed to be connected directly across the line.
There is one exception. There is a type of small motor with two identical windings that is reversed by switching the capacitor from one winding to the other. Your motor is not such a type.
I agree with Scotty's suggestion.


Bill
--------------------
"Why not the best?"
Jimmy Carter
 
Thank you, Scotty and Bill, for the information.
 
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