Outside unit fan does not run

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  #1  
Old 05-06-10, 06:41 AM
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Question Outside unit fan does not run

I have a 9 year old Ruud heat pump. The outside fan does not work properly. I noticed the problem a couple of weeks ago. I went outside and took the cover off, toggled the breakers a couple of times, and the fan magically started turning. Well, of course, it did not continue to work for long. Another time this was successful, as well, but when it would no longer start that way, I was able to manually push the fan with a stick and it would start, and run for a while. After doing some research, I ordered a new capacitor and replaced it yesterday. That did not fix the problem. So, at this point, I can still get the fan started manually, it will run for about 20-30 minutes, then stops. It appears to be providing cool air to the house, but just will not continue turning. There is a humming sound at the unit. The fan spins freely when the power is disconnected.
Well, I just tried one more time to see what would happen and get my description accurate. I turned the unit to heat, and checked the outside unit and the fan was not spinning (that may be the proper way for it to function - I don't know). Then I turned it back to AC and went outside and verified that the fan spins freely with the breakers off. I then turned the breaker back on and the fan started! I expect it will quit in a few minutes.
Does anyone have any thoughts as to what might be causing this? It's getting hot, here in Georgia!
Thanks so much!
Chan
 
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  #2  
Old 05-06-10, 08:03 AM
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Sounds like the fan is heating up and stopping. Since the cap has been replaced...and the humming is an indicator that the contactor is providing power to the fan and compressor..I would replace the fan motor.

Though it may spin freely...it could have damaged windings that are drawing more current thus causing it to overheat. Is the motor extremely warm/hot when it comes to a stop?
 
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Old 05-06-10, 09:20 AM
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Thanks for replying, Gunguy45

Yes, it feels pretty hot to me. I can place my hand on the top of the cover, but can only leave it there for a couple of secs.

If I replace the fan motor, should I replace the fan blades, too, or could I reuse them?

Thanks,

Chan
 
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Old 05-06-10, 09:34 AM
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No way it should be that hot...I think you found your problem. Cut off all power to the unit...remove the required wires and label where they go...diagrams are also helpful.. Remove the fan (might want to label which side is up and direction of rotation...though prob not required)...may need some rust buster spray. Don't bend/damage fins or lose any of the balancing weights if present.

Take the motor to an HVAC supply and get an exact replacement. A Grainger store or electrical supply may also have them. Also some appliance repair parts stores.

You won't find a new motor at a BigBox or most hardware stores.
 
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Old 05-06-10, 09:47 AM
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Thanks, again - I'll give that a shot and let you know if it works.
 
  #6  
Old 05-11-10, 08:28 AM
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I have not been able to find an exact replacement motor for the condenser fan. I have found a couple of possibilities, but the wiring is different. So, if anyone can help with the wiring, I would really appreciate it.

Here is the situation:
My old motor has 3 wires: 1 black, 1 brown, and 1 orange
A new motor I found has has 5 wires: 1 black, 1 brown, 1 orange, 1 yellow, and 1 purple.

My current connection it that the black goes to a circuit board, and the brown
and orange go to a dual capacitor - brown to the fan terminal and orange to
the common terminal. How would I wire the new motor to make it function
correctly (if it can be done)?

Thanks for any help.

Chan
 
  #7  
Old 05-11-10, 12:16 PM
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most new motors will have 4 wires, 2 brown that will go to a new mini cap that is installed with the motor, and 2 other wires, color is irrelevant that go to the contactor. it may appear that one of these wires (for the contactor) goes to the cap but actually it is connected to the contactor via an additional wire that connects to c on the dual capacitor
 
  #8  
Old 06-04-10, 03:54 AM
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Smile Successful Installation

Thanks, Gunguy45 and ender2272,

I wanted to wait a while to make sure everything was working as it should before posting a notice of success.

I wasn't convinced that the motor was the problem, as sometimes it would start as it should and run for several hours as normal. Other times I would have to give it a push, and it would run. In any event, I could not determine that there were any other problems, so, I purchased one of those multi-horsepower motors from the local electrical shop for appx. $70.00. I needed it to be 1/6 horsepower, so I hooked it up that way using 3 of the 5 wires, following the wiring schematic. Seems to be working great!

Thanks, again, for the input and direction.

Chan
 
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