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Fri 11 Jun, 2004 07:01 am
Hi, even though this is not "electronics," I couldn't find a better place to post this question.
My HVAC (heat pump) unit's fan has quit working. This is the outdoor fan; the one that cools the exposed coils.
In my experience, when one tries to manually turn a fan, and it does not, the motor is seized and needs to be replaced.
However, on this motor (only two years old), the fan spins freely except when energized. When the power is on, I cannot even manually turn the fan.
Do you know if this is a fault of the motor, or its external capacitor?
By the way, do you know how to test a capacitor and/or motor?
Thanks mucho,
General Tsao
A fast and dirty test for a capacitor failure is to disconnect it from the system and connect an ohmmeter to the terminals. A good capacitor will move the needle briefly in one direction or the other (but not both), and then give a reading of infinity ohms. If there's continuity, it is definately a bad condensor.
I've never seen this type of motor failure, either. Let us know?
The capacitor is for starting the motor turning. If it's bad the motor will turn while energized and should actually start up if you give it a shove manually. (That's the purpose of the capacitor - it sort of "kick starts" the motor turning and then cuts out..)
If the motor is frozen when energized I'd suspect a bad field winding which an electric motor shop could diagnose for you and repair. It might just be cheaper to buy a new motor though.
i agree with fishin; replace the motor; most likely a piece of the iron core around which the field wires are wound has broken loose, and is acting as an electromagnet when energized, functioning as a brake, rather than an impeller, thus locking up the fan.
new motor cheapest and easiest solution!
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