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  1. #1

    Condenser fan not turning

    This morning I looked out my window and noticed the condenser fan was not spinning on my heat pump. I know it normally doesnt spin when the unit is in defrost mode and didn't think it was unusual.. at first.. Then, about 15min later I looked at it again and it still wasnt spinning. The system was on, in heat mode, and the aux heat was not on.

    I went down to the air handler and felt the freon pipes. The suction was very hot, and the liquid was very cold. Usually the liquid is around room temp. Didnt have time to break out my temperature probe. Might do that tonight.

    Anyways, turned the system off for 20 minutes, started it back up and the fan looked like it tried to start turning, but didn't. Left it on for 5-10 minutes and more frost started to accumulate on the outside coil (outdoor temp ~30deg), so it wasn't in defrost mode. I was able to spin the fan with a stick and it moved freely, so it seems the bearings aren't siezed. It seems like it just quit, or the controller logic is really messed up and thinks it is defrost mode when it really isn't.

    I have the installer coming out to look at it tomorrow, but my question is, is there anything else to look at that could have been damaged by operating the unit like this? The last time I actually remember looking at the outdoor unit was a few days ago.

    Unit is a Fridgidaire FT3BD with indoor air handler B5BM. Both units are 2.5 ton.

  2. #2
    Join Date
    May 2000
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    Indianapolis, IN, USA
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    Not much you can do besides leave it on emergency heat so it doesn't try to run that way. The part should be under warranty whatever it is - motor, capacitor or board. You'll just owe service call and labor unless you have an extended plan.

  3. #3
    Join Date
    Nov 2006
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    Oregon
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    853
    ODF start relay or start capacitor would be my guess. A good tech. should be able to diagnose it pretty quickly.

  4. #4
    Join Date
    Aug 2004
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    Kentucky, Michigan, Ohio, Arizona, Colorado, Nevada, and Califormia
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    Refer to Loonies post. ODF doesn't have a start cap.
    "Surprised ?! If I woke up tomorrow with my head sewn to the carpet, I wouldn't be more surprised."
    Clark Griswold

  5. #5
    Join Date
    Aug 2003
    Location
    Fort Worth, TX
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    A motor can free spin when de-energized and lock up solid once power is applied.

    A heat pump condenser fan pulls double duty. Whereas its straight cool condenser cousin only runs its condenser fan in summer, the heat pump fan runs year round. So it wears out faster.

    As for damage to your system...probably not. If anything you weren't getting as much heat out of it vs. with the outdoor fan running. In cooling mode that would be a different story. A failed outdoor fan in cooling mode leads to high head pressure and an over-stressed compressor. In heating mode it means less heat picked up from the ambient air to be rejected inside the house...less load on system.

    Have your installer out to check the outdoor fan. You could be in for a replacement motor and fan blade (both should be replaced so new motor has balanced blade) if the problem is not control related.
    • Electricity makes refrigeration happen.
    • Refrigeration makes the HVAC psychrometric process happen.
    • HVAC pyschrometrics is what makes indoor human comfort happen...IF the ducts AND the building envelope cooperate.


    A building is NOT beautiful unless it is also comfortable.

  6. #6
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    Quote Originally Posted by lra View Post
    Refer to Loonies post. ODF doesn't have a start cap.
    Where does he say that? If it doesn't have a start capacitor then it's either a split phase induction motor or a universal DC motor. That would be an interesting (and uncommon) arrangement for an ODF.

  7. #7
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    Aug 2003
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    Quote Originally Posted by davefr View Post
    Where does he say that? If it doesn't have a start capacitor then it's either a split phase induction motor or a universal DC motor. That would be an interesting (and uncommon) arrangement for an ODF.
    It has a run cap in series with the start winding. In the trade a start cap is distinguished from a run cap for its microfarad rating is considerably higher and is only designed to be in the circuit momentarily. Run cap stays in circuit constantly.
    • Electricity makes refrigeration happen.
    • Refrigeration makes the HVAC psychrometric process happen.
    • HVAC pyschrometrics is what makes indoor human comfort happen...IF the ducts AND the building envelope cooperate.


    A building is NOT beautiful unless it is also comfortable.

  8. #8
    Join Date
    Nov 2006
    Location
    Oregon
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    853
    Quote Originally Posted by shophound View Post
    It has a run cap in series with the start winding. In the trade a start cap is distinguished from a run cap for its microfarad rating is considerably higher and is only designed to be in the circuit momentarily. Run cap stays in circuit constantly.
    Thanks!!

  9. #9
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    Aug 2003
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    Quote Originally Posted by davefr View Post
    Thanks!!

    You're welcome. Just don't let this guy replace your run caps (RCB, the Run Cap Bandit!)....


    • Electricity makes refrigeration happen.
    • Refrigeration makes the HVAC psychrometric process happen.
    • HVAC pyschrometrics is what makes indoor human comfort happen...IF the ducts AND the building envelope cooperate.


    A building is NOT beautiful unless it is also comfortable.

  10. #10
    Join Date
    Feb 2007
    Posts
    43
    I had that problem. Fan was making noise like it was trying to start. I called some smart guy, he said Start capacitor, yes it was. I don't remember 10 or 15 doll. I even started it with some stick before I replaced capacitor, so you can save money that way.

  11. #11
    Join Date
    Jun 2003
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    Florida
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    9,548
    On a higher end unit it might have a fan control on the OFM, and be operating correctly. Still worth a service call.
    If everything was always done "by the book"....the book would never change.

  12. #12
    Join Date
    Dec 2006
    Location
    Middle Tennessee
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    *

    Quote Originally Posted by davefr View Post
    Where does he say that? If it doesn't have a start capacitor then it's either a split phase induction motor or a universal DC motor. That would be an interesting (and uncommon) arrangement for an ODF.
    my 1 year old american standard 18 seer condenser fan has an ecm motor with no capacitor

    its (not) uncommon for trane or amercan standard high end systems to have these odf motors with no capacitors



    .

  13. #13
    Join Date
    Aug 2005
    Posts
    145
    I have the installer coming out to look at it tomorrow, but my question is, is there anything else to look at that could have been damaged by operating the unit like this?
    If you run a heat pump without the outdoor fan, in the heat mode, it is possible to slug the compressor with liquid refrigerant. OK

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