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  1. #14
    Join Date
    May 2008
    Posts
    356
    Well thinking back my first call on this unit over a week ago was a complaint that the unit was too noisy. The two straps had come loose on the suction line. Three mounting bolts had come loose on compressor. So I fixed these issues. It was shaking bad and making a lot of noise. A few days later I was called back because it quit running. Now I know why it was so noisy and vibrating excessively. Have no idea who my predecessors were.
    td55

  2. #15
    Join Date
    Jun 2012
    Posts
    19
    Quote Originally Posted by Six View Post
    You need to adjust the charge according to subcooling. Im guessing its TXV ?

    Qell some of those Carriers are fixed orifice. If they're cap tubes then superheat.

    At least you know now it was a legitmate issue.

    I cant imagine someone putting over 30 lbs of R22 in that machine.
    I can! I have a lot of issues lately with units being heavily overcharged. I had a Voyager earlier this week that was flooding back. I recovered almost 16 pounds from one stage that was meant for 8.5. Has become a common occurrence.

  3. #16
    Join Date
    May 2008
    Posts
    356
    Just called and checked on unit (Sat a.m.) still running, so I'll Tweek charge according to metering device and check air temps.
    td55

  4. #17
    Join Date
    May 2012
    Location
    southern california
    Posts
    30
    It's a packaged unit right? I wouldn't mess with subcooling, etc. It's already been overcharged. I would recover entire charge and weigh back in with nameplate charge. Then check subcooling, superheat and all that. You can reuse the refrigerant you pull out.

  5. #18
    Join Date
    May 2008
    Posts
    356
    Yes package unit. Recovering, pulling vac and weighing in charge was my next option. I thought I'd try adjusting first. Went back today. Unit was running but not cooling so l slowly increased charge and kept checking air temps. Started with a 5 delta t. I've got it up to 15 at best. If I add freon too fast, unit kicks out on overload. It kicked out twice during adjustments. I can hear it (when it I'm adding charge) fixing to kick off. I just kept shooting shots in. It' sensitive. Amps are 62 -65. Hard to check sh or sc. It is so hot and it is in the sun. I wonder if my readings will even be accurate. Thermometer on top of unit reading 140. Sun shines down in on compressor and lines. Tried to wrap suction and get reading. getting 30+ sh. However it's a txv, so I know i should use sc to charge, but the bottom line is - the air temps, right? I'm still hooked up to it (Gage's & tank)
    td55

  6. #19
    Join Date
    Jan 2004
    Location
    Lancaster PA
    Posts
    67,736
    A lot of systems are over charged by techs trying to get a good air temp split.
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    How many times must one fix something before it is fixed?

  7. #20
    Join Date
    May 2008
    Posts
    356
    I still haven't weighed recovery tank to see how much I recovered, but it was empty when I started and it feels almost full. It was a lot, and I only put a couple pounds back in today. Coils are clean, proper voltage, amps are within specs. I've been fighting this all week. I've been patient. Any more problems I'll pull vac and weigh in.
    td55

  8. #21
    Join Date
    May 2008
    Posts
    356
    Called back today. Breaker tripped on unit. Amperage has gone up to 85. When I left it was around 63 amps. It ran good for a few days. Voltage is 205 at the disconnect all the way to the compressor, loaded down - no voltage drop. Won't hold but 20 seconds. Reset it a few times to check amps and volts, then left it off for 10 minutes and tried again. Now it kicks within 3 or 4 seconds - pulling over 110 amps. Sounds like valves are sticking.
    td55

  9. #22
    Join Date
    Apr 2012
    Location
    Paper Street Soap Company
    Posts
    2,304
    Bottom line is proper charging methods. Focusing on the split as a method to add or remove refrigerant is hack methodology.

    Its a mistake. Your low split could be a symptom of several issues.

  10. #23
    Join Date
    Nov 2006
    Location
    Southeastern Pa
    Posts
    17,884
    Quote Originally Posted by tonydykes55 View Post
    Been up there all day. RLA = 62 on nameplate. All wires and connections clean. No voltage drop across contacts. 210 phase to phase at compressor. Been monitoring amps closely to see what it trips at. Oh, first thing pulled a hose up and cleaned cond coils with cleaner. Started up. Pulling 77 - 80 amps. Cut off after about 5 min. Comp only, not fans. 4 safety switches in series - hi limit, lo limit, internal OL's, and a CLO ( comp lockout) which is on a small ckt bd and that is what was opening, not the Ovlds. So I jumped them (CLO). A ckt breaker on the unit, feeding the compressor (not the disconnect) started tripping at that point. Can't find amp rating on it. Amps got higher as it got hotter - in the low to mid 80s. Won't run long enough at this point to get SH. So I started removing charge. Head pressure was 345. Suction 75 with clean coils. Bumped out all I could. Amps started dropping. Got recovery machine. Kept removing - checking amps. Took out maybe 20 lbs - didn't have scales up there. Factory charge is 19 lbs. got the amps down to 62. Head 235 suction 65. Dont know SH. Haven't checked air temps. All my equip is still on the roof. Had to take another call. It's looking good. I'll be back tomorrow to check air temps. It was running for over an hour when I left.
    Nope.

    The CLO only locks out the unit when the safety chain opens (and the sensing loop has to see at least 1.5 amps). You WERE tripping something. I'd pull the charge, vac it down, and weigh in. No telling what is in there, including non-condensibles.
    Last edited by timebuilder; 07-04-2012 at 05:23 PM.
    [Avatar photo from a Florida training accident. Everyone walked away.]
    2 Tim 3:16-17

    RSES CMS, HVAC Electrical Specialist

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  11. #24
    Join Date
    May 2008
    Posts
    356
    True. But I've run across very old units, like this one and have cleaned the coils, properly charged (whether by weighing, sc, or sh) only to find out that they are simply worn out (compressor, bearings, coils, motors - maybe a combination of all - not just one issue), then the only choice is a new unit, therefore the only other option is to get a good split regardless of the charge. Am I wrong. Thanks for the help everyone!
    td55

  12. #25
    Join Date
    May 2008
    Posts
    356
    Ok so I'll try sucking her down, pull deep vac and weigh in new charge. It wouldn't be cheap or easy to change compressor. But I'll say this - that compressor sounded grim on that last attempt. All the windings ohmed out good, not grounded either. Maybe there is hope.
    td55

  13. #26
    Join Date
    Nov 2006
    Location
    Southeastern Pa
    Posts
    17,884
    Quote Originally Posted by tonydykes55 View Post
    True. But I've run across very old units, like this one and have cleaned the coils, properly charged (whether by weighing, sc, or sh) only to find out that they are simply worn out (compressor, bearings, coils, motors - maybe a combination of all - not just one issue), then the only choice is a new unit, therefore the only other option is to get a good split regardless of the charge. Am I wrong. Thanks for the help everyone!

    Since you are pulling out charge anyway, finish the job and weigh it in. Then, you can eliminate that as a variable.
    [Avatar photo from a Florida training accident. Everyone walked away.]
    2 Tim 3:16-17

    RSES CMS, HVAC Electrical Specialist

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