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  1. #1
    Join Date
    Aug 2011
    Location
    Myrtle Beach SC
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    94

    Single pole contactor

    Is there a polarity with 240 2-phase power?
    Situation : Single pole contractor. Outdoor fan runs but compresser does not. I switched the "incoming" L1-L2 power. Compressor started.
    Am I missing something, I thought they were both 120v and had no polarity?

    Sent from my LG-P999 using Tapatalk 2

  2. #2
    Join Date
    Nov 2006
    Location
    Southeastern Pa
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    18,259
    Quote Originally Posted by Adamscarpentry View Post
    Is there a polarity with 240 2-phase power?
    Situation : Single pole contractor. Outdoor fan runs but compresser does not. I switched the "incoming" L1-L2 power. Compressor started.
    Am I missing something, I thought they were both 120v and had no polarity?

    Sent from my LG-P999 using Tapatalk 2
    Yes, but not in the way that you mean it.

    The L1 and L2 conductor's identity will have no impact on the operation of the unit, barring some sort of issue with the unit, usually involving a wiring error made during a repair.
    [Avatar photo from a Florida training accident. Everyone walked away.]
    2 Tim 3:16-17

    RSES CMS, HVAC Electrical Specialist

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  3. #3
    Join Date
    Dec 2002
    Location
    SouthEast NC ICW & Piedmont Foothills
    Posts
    7,635
    just a note, unless you are working in an older industrial complex; you're not dealing with 2 phase power.
    It`s better to be silent and thought the fool; than speak and remove all doubt.

  4. #4
    Join Date
    Aug 2011
    Location
    Myrtle Beach SC
    Posts
    94
    yeah. I see I made a mistake. What I meant to say was single phase power.

    now that I think of it I think it was tripped out on high limit. and timing just caught it at this point whenever tge wires switched the wires, it reset.

    Sent from my LG-P999 using Tapatalk 2

  5. #5
    Join Date
    Nov 2006
    Location
    Southeastern Pa
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    18,259
    Quote Originally Posted by dandyme View Post
    just a note, unless you are working in an older industrial complex; you're not dealing with 2 phase power.

    It IS confusing to some, because they see two phase legs instead of three. Single Phase comes from a single phase transformer, which usually has a center tapped neutral to provide 120 volt power.

    We still have real 2-phase in parts of SW Philly.
    [Avatar photo from a Florida training accident. Everyone walked away.]
    2 Tim 3:16-17

    RSES CMS, HVAC Electrical Specialist

    AOP Forum Rules:







  6. #6
    Join Date
    Aug 2012
    Location
    Iraq
    Posts
    1,066
    Quote Originally Posted by Adamscarpentry View Post
    Is there a polarity with 240 2-phase power?
    Situation : Single pole contractor. Outdoor fan runs but compresser does not. I switched the "incoming" L1-L2 power. Compressor started.
    Am I missing something, I thought they were both 120v and had no polarity?

    Sent from my LG-P999 using Tapatalk 2
    can upload us a photo of the unit electric wiring diagram

  7. #7
    i think the compressor just tripped off. there is no polarity between the wires because they're AC

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