need advice about A/C unit repair
Page 1 of 2 12 LastLast
Results 1 to 13 of 15
  1. #1

    Confused need advice about A/C unit repair

    I am a HVAC install mechanic that hasn't worked in the field in a few years and I'm in aposition where I have to repair a couple units. I never was a service tech, hopefully someone can help. The units are simple straight A/C with no thermostat. On the first one, the red wire to the capacitor in the outdoor unit keeps frying off. I replace it, but in a couple days it just fries off again. Obviously drawing too much current. What could the problem be?

    On the second unit, the compressor turns on for about 5-10 seconds then cuts right back off again. The unit only has a suction port so I cn only read the low pressure side but the gauge is in the retard when I put it on. What are the options with that one?

    Thanks for any help I can get.

  2. #2
    Join Date
    Nov 2004
    Location
    Austin, TX
    Posts
    869
    When wire burns off of a capacitor it is typically due to corrosion inside of the wire bundle causing excessive resistance. A poor quality crimp, loose terminal, rusty terminal, overheated metal or undersized wire are among causes of high resistance in subsequent repairs.


    There can be several issues that can cause the suction line to be in retard.
    In any case, putting your gauges on a line while it is in retard will pull the air from your hoses into the refrigerant circuit. You may now have refrigerant contaminated with air and moisture.

    You're asking a pretty basic question. I know much you can forget when you've been out of a trade for a while. I know there are all sorts of nooks and crannies in the trade where people never use certain parts of their training.

    It is most likely low on refrigerant or has a restriction in the refrigerant circuit. It could both with poor air flow too. Neglected equipment frequently develops problems until one of them snowballs into a failure. I can't tell from here.

    How to drill down and determine which one and what tools and techniques to use are beyond the scope of this area. At this point I have told my own out of town brother to call a professional.
    I am for doing good to the poor, but...I think the best way of doing good to the poor, is not making them easy in poverty, but leading or driving them out of it. I observed...that the more public provisions were made for the poor, the less they provided for themselves, and of course became poorer. And, on the contrary, the less was done for them, the more they did for themselves, and became richer.
    ― Benjamin Franklin

  3. #3
    Join Date
    Jun 2002
    Location
    south jersey
    Posts
    1,096
    There can be several issues that can cause the suction line to be in retard.
    In any case, putting your gauges on a line while it is in retard will pull the air from your hoses into the refrigerant circuit. You may now have refrigerant contaminated with air and moisture.


    How is this possible? Unit with suction line in retard usually means over pressure not under. Me thinks you got problems.
    You need to put the phone down and get back to work!

  4. #4
    Join Date
    Dec 2007
    Location
    houston, texas
    Posts
    3,787
    Quote Originally Posted by jnsrose View Post


    How is this possible? Unit with suction line in retard usually means over pressure not under. Me thinks you got problems.
    Do you think he means retard or below 0psig? I was thinking he meant the latter at first but who knows.
    I'm not tolerating Political Correctness anymore, from now on it's tell it like it is.

    Veto Pro Pak - The best tool bag you'll ever own






  5. #5
    Join Date
    Feb 2012
    Location
    san pedro ca.
    Posts
    362
    Your compressor could be overcharged or slugging, windings could be pulling high amps indicating limited life. You could have a restriction in system causing all of the above.

  6. #6
    Join Date
    Feb 2012
    Location
    san pedro ca.
    Posts
    362
    The suction gauge starts retarding at about 100 pds. The other end would be called a vacuum.

  7. #7
    Join Date
    Dec 2007
    Location
    houston, texas
    Posts
    3,787
    Being he is not a service tech I may assume that he is mixed up on what his gauge is telling him. Guess we will have to wait and see.
    I'm not tolerating Political Correctness anymore, from now on it's tell it like it is.

    Veto Pro Pak - The best tool bag you'll ever own






  8. #8
    Join Date
    Dec 2009
    Location
    maroon lazyboy
    Posts
    1,044
    i hate it when my gauges say "RETARD!"!!!!!

  9. #9
    Join Date
    Feb 2012
    Location
    san pedro ca.
    Posts
    362
    Quote Originally Posted by knave View Post
    i hate it when my gauges say "RETARD!"!!!!!
    You know you did something wrong when your gauges call you a retard.

  10. #10
    Join Date
    Dec 2007
    Location
    north suburbs of Chicago
    Posts
    513
    I have not gotten past the no thermostat part yet.

  11. #11
    Join Date
    Feb 2012
    Location
    san pedro ca.
    Posts
    362
    Maybe he meant a duct t-stat or a high side cut out or something. I don't think he'z coming back.

  12. #12
    Join Date
    Dec 2005
    Location
    Cincinnati, Oh
    Posts
    4,884
    Quote Originally Posted by Glennhvac View Post
    I have not gotten past the no thermostat part yet.
    Interestingly enough.....

    I stopped reading his post after I saw that.
    "Better tell the sandman to stay away, because we're gonna be workin on this one all night."

    "Dude, you need more than 2 wires to a condenser to run a 2 stage heatpump."

    "Just get it done son."

    Dad adjusted

  13. #13
    Join Date
    Mar 2008
    Location
    NC
    Posts
    1,460
    Quote Originally Posted by Glennhvac View Post
    I have not gotten past the no thermostat part yet.
    I caught that aslo.

Page 1 of 2 12 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event