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  • Compressor amperage

     fixbear updated 1 week, 4 days ago 2 Members · 8 Posts
  • beef

    Member
    April 24, 2021 at 2:53 pm

    Last I checked, the 2~ compressor should draw amperage on common start run during startup, then the relay takes the start capacitor out after getting to a specific back emf(voltage) or starting amps.

    Then you should only have common and run amperage. Other than bad relays what would cause amperage on the start winding during operation…. or is my thought process wrong? πŸ˜‘

  • fixbear

    Member
    April 24, 2021 at 4:42 pm

    Depends on the compressor winding design and the start system design. If it’s a PSC wound compressor, they have to have a cap current feed to run.

  • fixbear

    Member
    April 24, 2021 at 4:50 pm

    Depending on what make compressor your working on, check the field component manual for the right relay, cap, overload and possible wiring of them. I always carried both the Copeland and Tecumseh pocket books for that. They give you cut out voltage design of the relays as well. All units with a run cap will have current flow on the start winding.

  • beef

    Member
    April 24, 2021 at 5:02 pm

    Right, it’s not a CSCR. It’s CSIR, like most refrigeration compressors. the start leg should not draw amperage.

  • fixbear

    Member
    April 25, 2021 at 6:21 pm

    Beef, what make and model compressor are we talking about?

  • beef

    Member
    April 26, 2021 at 6:11 am

    See pic. 😁

    image
  • fixbear

    Member
    April 26, 2021 at 12:32 pm

    That’s a Copeland PFV. That means it’s a capacitive start, permanent split capacitor motor. Yes you will have current flow on the start winding in run mode. It uses both a start and run capacitor.

    The Start is a 914-008-51

    Run is 914-037-10

    relay is a 940-001-55

    You can find all this in the electrical parts guide.

  • fixbear

    Member
    April 26, 2021 at 2:24 pm

    Finally found the digital copy of the Electrical Handbook

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