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Thread: Intermittent condensing unit

  1. #1
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    Intermittent condensing unit

    Got a call for a condenser fan running but shutting off after a while cooling up to that point. After the owner notices it is no longer cooling, they shut it off and let it sit. After a while they turn it back on and it works for a while then repeats this process. Its a 2.5 ton champion heat pump less than five years old.
    Of course each time I show up to troubleshoot it runs fine with no problem.
    Capacitor is fine, contactor is fine, fan motor ohms out fine, fan relay on control board is fine, and the LED on the board displays good operating status.
    What am I missing here?
    Could it be the motor windings shorting out intermittently?
    Something with the defrost?
    Im new to the field so Im turning to the real pros for some help. Thanks.

  2. #2
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    What am I missing here?

    Amprege reading of motor for starters....motor should under warranty if the motor is bad.

  3. #3
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    Sounds like everything is fine.
    Officially, Down for the count

    YOU HAVE TO GET OFF YOUR ASS TO GET ON YOUR FEET

    I know enough to know, I don't know enough
    Why is it that those who complain the most contribute the least?
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  4. #4
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    Quote Originally Posted by jameshoff42 View Post
    What am I missing here?
    Im new to the field so Im turning to the real pros for some help. Thanks.
    What amps are the fan motor rated at (FLA), and what is the amp reading while the fan is running?

    Does it look like this is the original fan motor?

    As a tech in the field, you should aways post the model number of the unit in question, if you are expecting the best assistance.
    Instead of learning the tricks of the trade, learn the trade.

  5. #5
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    Intermittent condensing unit

    Is the blower turning off too? Is there a float switch?


    Sent from my iPhone using Tapatalk

  6. #6
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    I use a analog gauge that retains highest pressure. Leave it on for a day.. this will tell you if cfm is dropping out.

    Next time it fails, instruct customer to put his hand on cfm hub on condenser top and feel if it is smoking hot. Indicates if fan motor is tripping out and is bad

  7. #7
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    Fan shutting off, but is the compressor shutting off, too?

    By the time someone notices, both are probably off either due to component failure or voltage loss.
    The Food Stamp Program, administered by the U.S. Department of Agriculture, is proud to be distributing the greatest amount of free meals and stamps EVER.
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  8. #8
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    Fan off. Compressor shuts down. Happens all the time

  9. #9
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    If its a time and temp defrost board, check the defrost thermostat.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  10. #10
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    Im voting for the board

  11. #11
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    Quote Originally Posted by Snapperhead View Post
    Im voting for the board
    In person or mail in?
    Officially, Down for the count

    YOU HAVE TO GET OFF YOUR ASS TO GET ON YOUR FEET

    I know enough to know, I don't know enough
    Why is it that those who complain the most contribute the least?
    MONEY CAN'T BUY HAPPINESS. POVERTY CAN'T BUY ANYTHING

  12. Likes crazzycajun, icy78, newoldtech, Snapperhead liked this post.
  13. #12
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    Quote Originally Posted by Snapperhead View Post
    Im voting for the board
    Quote Originally Posted by 2sac View Post
    In person or mail in?
    Red or Blue

  14. Likes 2sac liked this post.
  15. #13
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    Quote Originally Posted by Snapperhead View Post
    Im voting for the board
    Bypass that in cooling mode and see it it fixes it, if not change the motor if you think that's it. As said before, warranty parts involved here. If everything is "fine" as OP said why Is he not lookin elsewhere like a float switch.

  16. #14
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    Jameshoff42 do you have a senior tech who can go back with you? This sounds like a teaching moment for someone.

  17. #15
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    Quote Originally Posted by theoldscroll View Post
    Bypass that in cooling mode and see it it fixes it, if not change the motor if you think that's it. As said before, warranty parts involved here. If everything is "fine" as OP said why Is he not lookin elsewhere like a float switch.
    along with just a little information

    Make
    Model
    Age
    Refer
    Repair history

    Just the basics!

  18. #16
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    Sure helps if you get Ho involved.
    Show him how to check float switch. How to recognize if blower is running and if cu is running. Ice on suction.
    This is information we seek when we get a call for service.
    Ho will not be happy to get a bill for numerous trips, especially if it is a warranty part. His labor is a lot less then your labor

  19. #17
    Hurst11 is online now Professional Member/Membership Committee
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    Aftermarket motor? Is it the correct rpm,hp? If aftermarket make sure the amp draw of it is the same or very close to amp rating on the original motor.

  20. #18
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    Quote Originally Posted by jameshoff42 View Post
    Got a call for a condenser fan running but shutting off after a while cooling up to that point. After the owner notices it is no longer cooling, they shut it off and let it sit. After a while they turn it back on and it works for a while then repeats this process. Its a 2.5 ton champion heat pump less than five years old.
    Of course each time I show up to troubleshoot it runs fine with no problem.
    Capacitor is fine, contactor is fine, fan motor ohms out fine, fan relay on control board is fine, and the LED on the board displays good operating status.
    What am I missing here?
    Could it be the motor windings shorting out intermittently?
    Something with the defrost?
    Im new to the field so Im turning to the real pros for some help. Thanks.
    Hi Jame, have this problem been solved? I also have similar problem with a one-year old Grand Aire unit. Thanks.

  21. #19
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    Quote Originally Posted by scampbyc View Post
    Hi Jame, have this problem been solved? I also have similar problem with a one-year old Grand Aire unit. Thanks.
    "Jameshoff42" hasn't been on this forum for almost a year and a half, so I doubt he will answer your questions.

    We would really appreciate it if you would start a new thread on your current issue, rather than bring back to life a 2 year old thread.

    And as a "Homeowner", please start that thread in the "AOP Residential HVAC" forum.

    Thanks for your understanding.
    Instead of learning the tricks of the trade, learn the trade.

  22. #20
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    Quote Originally Posted by rundawg View Post
    "Jameshoff42" hasn't been on this forum for almost a year and a half, so I doubt he will answer your questions.

    We would really appreciate it if you would start a new thread on your current issue, rather than bring back to life a 2 year old thread.

    And as a "Homeowner", please start that thread in the "AOP Residential HVAC" forum.

    Thanks for your understanding.
    I will do that. Thank you for your suggestion.

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