new h/p haveing strange problems
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  1. #1
    Join Date
    May 2001
    Location
    Abilene,texas
    Posts
    246

    Angry

    hmmmmmmm question. I have been on a unit all day but the following is the results tell me what you all think.
    I arrived at the unit and this is what I found, supply temp 140 return temp 71 suction pressure 89 discharge 400+ LLT 142 sc14 SLT56 sh4 DLT183 duct static was .50 there were no restictions unit is 6 mo old we suspected bad comp it was replaced and unit was tripple evacuated and pulled to 570 microns it is acting like low air flow but it has the proper moter and is going the right direction coil is clean and filter is clean. so to recap this is a 3.5t h/p. we changed compressor,capacitor,contactor,and added drier pulled screen from pistons and checked pistons for proper size. pistons are correct air flow is good but still has pressures and temps not normal in heating. switch to cooling and unit is in perfect condition no problems. have a couple ideas and will wait to see what you say to confirm my suspicions

  2. #2
    Join Date
    Nov 2001
    Posts
    1,874
    High outdoor temp,
    being from Az,

    What is the secondary heat source?
    Is it running at the same time ?
    Rev valve not switching all the way .
    If you try to fail, and succeed.
    Which have you done ?



  3. #3
    Join Date
    Oct 2004
    Posts
    3,400
    Nevermind...



    [Edited by bwal2 on 02-08-2005 at 10:39 PM]

  4. #4
    Join Date
    Nov 2003
    Posts
    257
    .50 duct static? Was this supply? return? or total? If supply or return only this is grossly too high unless it is supply static on a mobile home. If it is total static then it is marginally high. The high discharge pressure, low subcooling and what would be high for my climate discharge temperature also point to low airflow.

    Something that I have seen show similar symptons are:

    1.) Oversized or bypassing metering device in the outdoor unit. If the unit uses an FCCV type metering device it may not be seating in heat mode, overmetering refrigerant.

    2.) If the outdoor unit has an expansion valve with an internal check valve the internal check valve might be hanging part way open.

    3.) If it's a Trane or American Standard product the check valve in the outdoor unit may be hanging open. This check valve looks like a piece of copper tubing with 2 or 3 crimps in it that hold the check valve in place.

    What were the indoor and outdoor temperatures.

    If the indoor side is fossil fuel was the furnace running?

    The high head pressure will nearly always eliminate the reversing valve.

  5. #5
    Join Date
    Sep 2004
    Location
    Glendale AZ
    Posts
    299
    89 lbs suction--- 400 lbs head-- sounds like you got a overcharged systme. Check your scale if you just changed a compressor.

    Why did you change the first compressor?

    Is it a split systme or package unit?

    [Edited by danj on 02-08-2005 at 09:49 PM]
    The bitterness of poor quality remains long after the sweetness of low price has gone.

  6. #6
    Join Date
    May 2001
    Location
    Abilene,texas
    Posts
    246

    reply

    OK here we go This is a package system it is a Goettl I didnt mention it before because 90% of you wouldnt know what it is. this unit has fixed metering device (pistions)it is a 13 seer system. we charged the system a couple times with a good quality scale, this unit does not have an accumulator so i was thinking that may be the problem cause it is acting like an over charge, but when i remove r-22 i drop my pressures to 72/355 this keeps it from tripping on high pressure i still get 130 supply temp.

  7. #7
    Join Date
    Mar 2004
    Location
    Grottoes VA
    Posts
    5,856
    outside temp?
    Karst means cave. So, I search for caves.

  8. #8
    Join Date
    Nov 2001
    Posts
    1,874
    Are you sure the piston is in the right way.
    Funny things happen at those factorys.
    Juan & Pedro can get mad and do things to mess with ya, LOL

    Your going to cook that compressor running at those head pressures. Thats why your supply temp is high. The heat has to go some where.
    If you try to fail, and succeed.
    Which have you done ?



  9. #9
    Join Date
    Feb 2005
    Location
    Dothan, Al
    Posts
    3,453
    I had figured when reading, that there was no accumulator in the system, and yes that can cause your problems.

    set the system charge for proper heating operation, then check the cooling cycle.

    any overcharge will show up more in the heating cycle than in the cooling cycle

    need to install accumulator probably

  10. #10
    Join Date
    Nov 2001
    Posts
    1,874
    The lack of an accumulator would be more of a problem if the coils are not matched.

    Do you think the factory mis-matched the coils. Without an accumulator you would need a slightly bigger indoor coil to make room for the extra refrigerant. In the heating mode. It would only mean a matter of inches or loops to a coil.

    In the cooling mode with the outdoor coil being the size they are you, don't see the problem when you don't have the accumulator.
    If you try to fail, and succeed.
    Which have you done ?



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