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  1. #14
    Join Date
    Dec 2002
    Location
    Houston,Tx.
    Posts
    16,080

    Re: Norm

    Originally posted by fat eddy
    ( we may be able to begin) what if one hole side or the entire top of the compressor was rusted Norm would that not give you any indication?
    O yea I have run across many like that in my 27 years I just install a new case. ROFLAO!!!
    __________________________________________________ _______________________
    “Experience is a hard teacher because she gives the test first, the lesson afterwards". - Vernon Law

    "Never let success go to your head, and never let failure go to your heart". - Unknown

  2. #15
    Join Date
    Jun 2003
    Location
    Hell Hole Swamp
    Posts
    4,180
    LMAO.....this new guy is funny, the air must be pretty thin up there on top of that HVAC mountain

  3. #16
    Join Date
    Jan 2005
    Posts
    175
    Line set correctly ran and sized? Air flow problems, txv problems (bulb insulated?).

    Once did a job for a guy who lacked about 500 sq inches on r/a and the plenum had (2) 12" ducts that split to 2 more 12" ducts then down to 8 & 6 inches. His compressor was mechanically failed (run but not pumping). This was his second system in the house installed both times by same contractor (first failure was same). I ripped everything out, ran all new ducts, made r/a correct size and now he can hear his tv with the a/c running.

    Did a commercial job where I had a 71/2 ton compressor changeout, only had 400 sq inches return through ceiling into air handler room and the door was always kept closed. Had carpenters install louvers in the door and all was well after that.

    Check r/a sizes and supply air duct sizes that you currently have for the unit.

    Compressors just don't fail-- always a reason.

  4. #17
    The last time they replaced the compressor a engineer came out from manfactuer and checked water flow in loop , with both A&B running ewt was 75.5 and exiting temp was 82.2 with just A compressor running ewt was 74.3 and exsiting was 77degrees the pressure drop was 6 psi. He looked on chart and said this was normal.These tempatures were after the unit had been put back in service and had run for a few hours.
    They looked at duct work and said it was ok but they did not check any airflow and I can see a couple of big leaks right where it comes off of unit and feel them on down the trunk. When unit is running there is not any noise from airflow in duct work but you can barely feel any air moving even on high speed. I will measure the size of r/a and post later this evening. But as I said ealier I can not get them to furnish any of this in writing it is just information I gleaned from him while he was here. 1st compressor 45 days 2nd compressor 4.5 yrs , 3rd compressor 3 months run time. No rust or corrosion of any type on outside of compressor.
    Thanks for the replys

  5. #18
    I measured the return air and the plenum at the unit is 32x8 and has a 29x8 inch opening, it runs on upstairs they used the floor joices for ducting and there is a 22 x12 riser upstairs and it has a 20x20 opening in it.

    I basiacly just want a geotherm unit that functions well and will last the 20+ years , if there was a major problem with the unit I would think that the installer would verify that,and get somekind of rembursment on his end. The wholesaler and the engineer refuse to admit any problems and told me that i just got some bad compressors.
    But they are going to replace the whole unit now, I think they know what is wrong with it or I hope they would be able to find out as they are professionals, and they just don't want me to know.Earlier the installer offered me a new air to air free as a replacment for the geotherm.

    How many of you guys would eat the labor on 2 compressor install and then eat the labor to install a new unit if all your work was a ok ?

    Somethings fishy around here,and i do not want all this to start happening again 2-5 yrs down the road.

    Does any one have any suggestions on how to proceed.

    they told me it would take a week to get a new unit in and it will be 2 weeks tommorow and I have not heard nothing , but this has been thier standard MO ( installer and wholesaler)they never get back to me untill after I get all worked up and make a lot of nasty threats and then send it to all 3 parties. I have over 20 pages of documentation over the 5 yr period of a lot worse situations than this, it took me overe 70 days to get them to fix the last compressor.

    Any Suggestions


    Thanks

  6. #19
    Join Date
    Aug 2003
    Location
    Fort Worth, TX
    Posts
    11,358
    Do the compressor failures always occur when you have been using the system for heating (I'm assuming this is a heat pump, as I don't work on geothermal units)?

    Locked rotor, blew the pot, locked rotor...sounds like either an oil return problem or, having also blown out two high pressure switches, a head pressure problem. Anyone actually spend any time taking the refrigeration pulse of this system? (superheat/subcool/delta T's, etc) I can't imagine anyone just slapping in three compressors and having NO CLUE as to why two of them failed! But *sigh* I guess I'm just the oddball in that I like to find out WHY instead of just trying to bandage a problem.
    • Electricity makes refrigeration happen.
    • Refrigeration makes the HVAC psychrometric process happen.
    • HVAC pyschrometrics is what makes indoor human comfort happen...IF the ducts AND the building envelope cooperate.


    A building is NOT beautiful unless it is also comfortable.

  7. #20
    The most I could get done was a engineer from the manfactuer came out after 2nd compressor and checked loop temps pressure drop and verfied GPM as listed in one of my previous post .
    The 2 locked rotors failures were in Heating mode and the 1 where it blew out the pot head was in cooling mode.

    The high pressure switchs did not blow out but they replaced the first one when the starter relay kept chattering in and out and compressor would lock out, but it would evuntually start. I would have this problem every year when the ground would start thawing and the water would sink down into the earth.Always around the end of Januarury.

    Why would'nt 1 of the midwest largest wholesaler of carrier products not want to find the cause of these failures?

    I have had a compressor fail on each refrigeration circuit so it would have to be something that is common to both circuits, Loop, Air flow what else? Am I misundestanding this when it says isolated refrgeration Circuits?

    Thanks

  8. #21
    Join Date
    Jan 2005
    Posts
    175
    From the tonnage you have and the r/a and s/a dimensions you stated, you have an airflow problem.

    You need 144 sq inches per ton (4x144=576) r/a.
    Sorry I can't give the duct dimensions required for the cfm's for that info is in my rubbermaid container in my service truckbed buried behind a bunch of stuff.
    Get a ductulator to figure what you need for supply air.

    Sorry I am not an installer (and never have been) but when I figure I have an air flow problem, I have the materials to do the research.

    Good luck!

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