Condenser Fan Motor Issues

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stryker2000

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I was hearing a humming through the air ducts and went outside to hear the ac unit making a ridiculously loud noise. I turned it off and spun the motor blades slowly and it vibrated and shook the unit. The old motor shaft moves in and out quite a bit compared to the new one. Replaced motor and capacitor. Now, it comes on, the loud noise isn't there but the blades are turning slower and sounds almost like a grinding sound. It doesn't look like it is hitting on anything. I turned it on again and same thing. Blade spins slower than before. New motor spins freely and smooth. No noise and no vibration when I turned it by hand. The old motor ran extremely noisy, very wobbly and vibrated unit but it spun full speed. I looked up both motor and capacitor and replaced exact units.
 
If you have proper voltage then it would seem that you have purchased a bad motor, capacitor or both.
 
I understand the slow turning may be due to wiring or the capacitor. Any ideas why the sound is there? It's almost like something internal is moving or scraping faster than the blades themselves. The rotation is correct as I can see .

I should add that there is no noise when I manually spin the blades. Is there a difference when the motor has power?
 
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Yes. When power is applied the motor is struggling to run but can't due to some defect inside. Are you sure you wired it up correctly?
 
Absolutely positive. I took pictures prior as well as researched to double check the wiring. I was worried when the original problem came up because I couldn't isolate the noise due to it being so loud. That's when I spun the motor and it just shook the whole unit with the slightest movement and the shaft moves in and out. Is there a way to isolate components to verify this 100%? I'm sure I'm thinking too much into it since I'm broke and hoping for the best scenario :)
 
I removed the motor again just to look around. It seems that the blade itself is the culprit. The blade is spinning freely....but so is the connection to the shaft. I'm going to guess the hub isn't solder-able so I may just need to order a new blade.

Are there any alternatives to the LA01RA321 Revcor blade? I didn't realize how expensive these things were.
 
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There should be a set screw to hold the yolk of the fan blade tight with to motor shaft. You also have to have the correct shaft diameter for the fan blade. Align the flat side of the motor shaft with the set scene of the fan blade yolk and the tighten the set screw.
 
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