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  1. #1
    Join Date
    Feb 2007
    Location
    Great Lakes Region
    Posts
    575

    Scroll running backward

    No cooling call. A new 3 phase Carier Rtu that was installed in winter. 4 ton scroll. Installing contractor MIA. It Never ran in cooling until today. It ran backwards for about 6 hours im guessing. Comp was off on IO I let it cool, reversed leads and everything was normal. What can be expected for the future of this unit?

  2. #2
    Join Date
    Dec 2002
    Location
    Arizona
    Posts
    4,368
    Quote Originally Posted by kamikaze126 View Post
    No cooling call. A new 3 phase Carier Rtu that was installed in winter. 4 ton scroll. Installing contractor MIA. It Never ran in cooling until today. It ran backwards for about 6 hours im guessing. Comp was off on IO I let it cool, reversed leads and everything was normal. What can be expected for the future of this unit?
    Only time will tell!
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  3. #3
    Join Date
    Apr 2012
    Location
    Paper Street Soap Company
    Posts
    2,304
    Usually they heat up and trip the internal overload , reset and the do it all over again.

    Im guessing this thing is under warranty ? Ask the customer if they want to swap out the comp. If they will pay labor that is.

    Reaaly I thinks its probably fine. I had a data aire that ran backwards for two days. That was 3 years ago. and its still running.

  4. #4
    Join Date
    Jun 2008
    Location
    Rochester, NY
    Posts
    61
    I would've checked pressures, temperatures, ohmed out the compressor, and recorded amp draws on my paperwork. Record everything to CYA!! If all that checked out and the compressor sounded okay, just hope for the best....that's all you can do really.

  5. #5
    Join Date
    Jun 2008
    Location
    Rochester, NY
    Posts
    61
    Quote Originally Posted by commtech77 View Post
    Usually they heat up and trip the internal overload , reset and the do it all over again.

    Im guessing this thing is under warranty ? Ask the customer if they want to swap out the comp. If they will pay labor that is.

    Reaaly I thinks its probably fine. I had a data aire that ran backwards for two days. That was 3 years ago. and its still running.
    I agree too it's probably fine. But I really doubt carrier is gonna warranty a compressor that was wired improperly to begin with.

  6. #6
    Join Date
    Jan 2008
    Location
    Dallas ,Texas
    Posts
    3,707
    Quote Originally Posted by pvc1984 View Post
    I agree too it's probably fine. But I really doubt carrier is gonna warranty a compressor that was wired improperly to begin with.
    You are probably right but how would they ever know?
    UA 100

    It takes three people to do anything around here. Two do the work, one explains to the crowd of people who showed up when they seen smoke and flames.

  7. #7
    Join Date
    Feb 2012
    Location
    central Florida
    Posts
    154
    Good advice document your work so it does not come back to bite you later. that has saved me on several occasions.They cannot say you were at fault that way and believe me they will.

  8. #8
    Join Date
    Sep 2006
    Location
    Ohio
    Posts
    469
    So was the blower also running backwards or was the compressor wired wrong from the factory?

  9. #9
    Join Date
    Jan 2006
    Location
    DFW Metroplex
    Posts
    4,910
    Quote Originally Posted by hands View Post
    So was the blower also running backwards or was the compressor wired wrong from the factory?
    They run 3 phase blower motors? Most of the 3 phase gas pack RTU's I've seen, have single phase blowers.....but I don't get a steady diet of 'em either.
    "The problem is the average person isnt tuned in to lifelong learning, or going to seminars and so forth. If the information is not on television, and its not in the movies they watch, and its not in the few books that they buy, they dont get it" - Jack Canfield

  10. #10
    Join Date
    Apr 2012
    Location
    Paper Street Soap Company
    Posts
    2,304
    Quote Originally Posted by pvc1984 View Post
    I agree too it's probably fine. But I really doubt carrier is gonna warranty a compressor that was wired improperly to begin with.
    Sure they will.

    You didnt wire it in wrong and what Carrier doesnt know wont hurt them. Your customer comes first.

  11. #11
    Join Date
    Jun 2008
    Location
    Rochester, NY
    Posts
    61
    Quote Originally Posted by commtech77 View Post
    Sure they will.

    You didnt wire it in wrong and what Carrier doesnt know wont hurt them. Your customer comes first.
    Don't get me wrong...I agree with you 100%. I would take care of the customer anyway I could and definitely do what I can.

    This thread also reminds me...on new Carriers....make sure and look at the voltage ratings on the blower motor. Already seen it a couple times where they put a 208 volt motor in a 460 volt unit. The motor doesn't usually last long lol.

  12. #12
    Join Date
    Sep 2006
    Location
    River Forest IL
    Posts
    70

    Something to consider-

    If you have a unit that has 3 phase compressors and blower motor, they should both be phased properly from the factory (A-B-C). That doesn't mean they can't be wired wrong in the field, but if one is running backwards, they both should be. (though "should" doesn't mean "always is the case") Maybe when they started it up it in the field it was too cold to start up cooling, and the compressor was phased wrong at the factory-maybe they meant to do a cooling startup when conditions were better, and would certainly have caught it then.
    If the compressor is 3 phase and the blower is single, it's still possible that the compressor was started up and running in the right rotation at one point, but if someone changed the contactor and accidentally crossed up the wiring, that would reverse rotation also.
    Not to mention: there could have been a phase reversal at the pole, coming into the building (though that would affect all 3 phase motors from that feed), the panel could have been changed, and that breaker had wiring crossed.
    All I'm really getting at is just because we run into equipment running backwards, doesn't mean it was always running backwards...things happen. Sometimes equipment gets started up correctly, and outside forces change things.
    And....sometimes folks just hit the go button, hope for the best, and head for the bar.

  13. #13
    Join Date
    Sep 2006
    Location
    Ohio
    Posts
    469
    Quote Originally Posted by markettech View Post
    They run 3 phase blower motors? Most of the 3 phase gas pack RTU's I've seen, have single phase blowers.....but I don't get a steady diet of 'em either.
    Most 3 PH RTU's I've seen have 3 PH blower motors. They may only use a two pole contactor, but they run a wire to the motor that is hot all the time.
    I'm not saying that your unit has a 3 PH blower, but you may want to check it if you're not sure.

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