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  1. #1

    starting components or bad compressor

    Hello All, I have a compressor that is not starting, MFR. LRA are 54 and I am pulling 44. Compressor is 208-230 single phase. starting components consist of start cap with resistor, run cap and potential relay. I am reading 208v at breaker before start up and on start up. What is the proper way too troubleshoot if its a bad compressor or bad starting components? Compressor has been running for years prior to this, so all electrical wiring is good. Thanks in advance

  2. #2
    Join Date
    Mar 2013
    Location
    Springville, NY
    Posts
    2,137
    swap out start components with known good and see if it starts
    ~~
    Political Correctness - the Language of Wussies

  3. #3
    Join Date
    Jun 2003
    Location
    Gainesville
    Posts
    14
    Well... This is what I would do, others might tell you something different. I would check the microfarads of the two capacitors. Cut the resister off the start capacitor to check it. If you cut the leads of the resister as close to the capacitor terminals then you can add slide on connectors to the leads and re-attach if needed. If both capacitors check out then replace the potential relay with a new one. I keep a universal on the truck just for this particular occassion. If the culpret is the relay and the universal has it going I will work on getting the correct relay designed for that particular compressor. Universal is just to get you going on a Saturday night or troubleshooting which you have here.

    If the compressor still won't start then you have a locked rotor compressor.

    I am willing to bet your issue lies with the relay. Current flowing through the start capacitor but the relay is not switching to the run capacitor.

    Again others might tell you different but this is where I would start

  4. #4
    Join Date
    Apr 2010
    Location
    San Diego, CA
    Posts
    172
    ^ that's exactly how I roll with these things.

  5. #5
    Join Date
    Mar 2013
    Location
    Cherokee Co. Texas
    Posts
    76
    Have you Ohm'ed out the compressor and checked the windings to ground yet? I'd get out the meter first and check that and the cap before I start throwing/swapping parts. Pot. relay coil and contacts (N.C).

  6. #6
    Join Date
    Jan 2005
    Location
    where it's nice and warm
    Posts
    236
    You already have your amp meter in your hand,continue using it to check how much amps is drawn by the run and the start windings. If they are both pulling amperage then you have good windings but a locked up compressor.If your compressor starts but the start winding does not drop out and the overload opens, you have a bad relay. If your start winding does not pull any amperage you have open windings,bad capacitors or relay.If your run winding pulls no amperage you have open winding.I guess you know what happen if the overload is open.

  7. #7
    Join Date
    Oct 2012
    Location
    Wisconsin
    Posts
    2,681
    ^^^ What they said.

    You can ohm out the potential relay as well. You should have continuity between 1 and 2. Between 2 and 5 will read resistance of the coil. This isn't a definitive test to tell if its good or bad, but if either read open you've got a problem.

    Ohm out the compressor checking to ground and between windings.

    Check the microfarads of the capacitors.

    Check the amp draw on the start winding.

    If you believe its a stuck compressor, try whacking it with a rubber mallet or 2x4 to free it up, and get it running till you can get a new compressor.

  8. #8
    thanks to all. compressor was locked up

  9. #9
    Join Date
    Dec 2012
    Location
    Illinois
    Posts
    147
    Umm. If it's got a start and run capacitor then you will have two different amp readings on the "start" winding. A starting reading (start capacitor) and a running reading (run capacitor) as long as the potential really is working.

  10. #10
    Join Date
    Jun 2013
    Location
    N. Canada
    Posts
    330
    Quote Originally Posted by Elite-Mech View Post
    thanks to all. compressor was locked up
    Then why were you getting 44A instead of LRA of 54A?

    I presume you had let the compressor cool.

  11. #11
    Join Date
    Sep 2002
    Location
    Virginia
    Posts
    2,750
    Quote Originally Posted by Elite-Mech View Post
    thanks to all. compressor was locked up
    did you whack with a hammer to get it going ?

    I do that all of the time , no problems most of the time.

    Problem was usually a dirty ass condenser coil made it run hot

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