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  1. #1
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    Apr 2006
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    Trane RTAA Unloader/Lip Seal Problem????

    So I have had a 100 ton compressor on a Trane RTAA270 chiller tripping on low oil flow every other day. So by reading the bulletins, and looking over here I figured out what was going on. Basically the compressor would start up at about 100%-108% RLA. I verified that the unload solenoid was energized for the intial 30 seconds. So I checked the oil level on the separator. It appeared to be normal, but it was slightly difficult to make the sight glass show the level at a consistant point. Is there a trick to doing this? I checked the bearing cavity pressure, and it was about 20-30 psi higher than suction like normal. After running everything through its paces I assumed that something was wrong with the unloader valve. So I got new valves. I found that the unload pill filter was plugged up. A trane bulletin I read said to discard the pill filters due to them being for start up debris. Should I get new ones? Well after I got everything back up and running. I heard a hot gas leakage noise near the discharge line of the compressor. It sounded internal to the compressor. The RLA % starts out a lot lower now, but still hovers kind of high. I remeasured the bearing cavity pressure, and now it is about 110 psi higher than the suction pressure. The system is now tripping on low oil flow immediately. By removing the pill filter restriction did I open up a possible lip seal problem now? I haven't seen a defective lip seal yet. Can someone tell me if the issues I am having now is a lip seal? I order a lip seal kit to install tomorrow, but I just want to make sure that I am right. So if one of you RTAA experts can give me some advice I would greatly appreciate it. The wierd thing is I deenergized the unload solenoid to simulate a complete restriction, and the hot gas can still be heard internally. I installed the valves, and gaskets the exact way that I took them off.

    Thanks!
    J. King

  2. #2
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    Mar 2004
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    You didnt read enough of the stuff on here about RTAA's and oil flow codes and I hate repeating myself over and over and over and over and over and over .
    Use the keyword search grab a case of cold ones and read away .....enjoy .. ALL and I mean ALL the answers you need are there .
    The 64 roars to life Whoo hoo ...shes a rolling chassis .
    You bend em" I"ll mend em" !!!!!!!
    I"m not a service tech.. I"m a thermodynamic transfer analyst & strategic system sustainability specialist
    Best Austin Healey In Show twice in 2013 .....All those hrs paid off .

  3. #3
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    Jul 2009
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    In a mechanical room....
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    “It takes courage to grow up and turn out to be who you really are.”

    - E.E. Cummings

  4. #4
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    Jul 2009
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    Quote Originally Posted by Healey Nut View Post
    You didnt read enough of the stuff on here about RTAA's and oil flow codes and I hate repeating myself over and over and over and over and over and over .
    Use the keyword search grab a case of cold ones and read away .....enjoy .. ALL and I mean ALL the answers you need are there .
    I was five seconds away
    “It takes courage to grow up and turn out to be who you really are.”

    - E.E. Cummings

  5. #5
    Join Date
    Apr 2006
    Location
    Columbus, Ohio
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    797
    I have read most of the posts. I guess my only concern is that for it to be a lip seal they say that the bearing cavity pressure gets up to discharge pressure. Mine has never got that high, but it is higher than normal. Could this still be a lip seal problem?

    Normal = 20-30 psi higher than suction
    Mine = 110 psi higher than suction, but still lower than the discharge pressure by about 75 psi - 100 psi.
    J. King

  6. #6
    Join Date
    Mar 2004
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    ottawa canada
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    Depends how much the lip seal is leaking . If its actually leaking . And if you have read the other posts you should know what the start amperage range should be .
    The 64 roars to life Whoo hoo ...shes a rolling chassis .
    You bend em" I"ll mend em" !!!!!!!
    I"m not a service tech.. I"m a thermodynamic transfer analyst & strategic system sustainability specialist
    Best Austin Healey In Show twice in 2013 .....All those hrs paid off .

  7. #7
    Join Date
    Mar 2004
    Location
    ottawa canada
    Posts
    2,075
    said to discard the pill filters due to them being for start up debris.

    You answered your own question
    The 64 roars to life Whoo hoo ...shes a rolling chassis .
    You bend em" I"ll mend em" !!!!!!!
    I"m not a service tech.. I"m a thermodynamic transfer analyst & strategic system sustainability specialist
    Best Austin Healey In Show twice in 2013 .....All those hrs paid off .

  8. #8
    Join Date
    Apr 2006
    Location
    Columbus, Ohio
    Posts
    797
    yes it should be 40-45%. Can you typically hear a lip seal leaking as I am hearing some sort of hot gas leakage internal to the compressor?
    J. King

  9. #9
    Join Date
    Mar 2004
    Location
    ottawa canada
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    Can you typically hear a lip seal leaking as I am hearing some sort of hot gas leakage internal to the compressor?

    Discharge check valve leak ?
    The 64 roars to life Whoo hoo ...shes a rolling chassis .
    You bend em" I"ll mend em" !!!!!!!
    I"m not a service tech.. I"m a thermodynamic transfer analyst & strategic system sustainability specialist
    Best Austin Healey In Show twice in 2013 .....All those hrs paid off .

  10. #10
    Join Date
    Apr 2006
    Location
    Columbus, Ohio
    Posts
    797
    Quote Originally Posted by Healey Nut View Post
    Can you typically hear a lip seal leaking as I am hearing some sort of hot gas leakage internal to the compressor?

    Discharge check valve leak ?
    Is there something that I did that would of caused this? I just changed out the 2 solenoid valves. It wasn't making this noise before. Is this discharge check valve repairable?
    J. King

  11. #11
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    Mar 2004
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    ottawa canada
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    I am only guessing about the check valve . Im not sure how you can determine the noise as these things are screamers ,so how you differentiate the noise ???.
    Did you change the hockey puck when you had the compressor open . If not you should have .
    Are you 110% certain you got the solenoid gaskets on the right way round with all the correct holes in the correct places ??
    The 64 roars to life Whoo hoo ...shes a rolling chassis .
    You bend em" I"ll mend em" !!!!!!!
    I"m not a service tech.. I"m a thermodynamic transfer analyst & strategic system sustainability specialist
    Best Austin Healey In Show twice in 2013 .....All those hrs paid off .

  12. #12
    Join Date
    Apr 2006
    Location
    Columbus, Ohio
    Posts
    797
    Quote Originally Posted by Healey Nut View Post
    I am only guessing about the check valve . Im not sure how you can determine the noise as these things are screamers ,so how you differentiate the noise ???.
    Did you change the hockey puck when you had the compressor open . If not you should have .
    Are you 110% certain you got the solenoid gaskets on the right way round with all the correct holes in the correct places ??
    Hockey puck? I lined the 2 port holes on the gasket up with the holes on the solenoid. I verified how the gaskets were intalled before, and I did the same thing. I also marked the hold valves upon removal, and made sure I reinstalled them exactly how I removed them. I will verify the gasket orientation again tomorrow. It is just a different kind of noise than it was making before, and the other compressors on this chiller do not sound like this.
    J. King

  13. #13
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    Mar 2004
    Location
    ottawa canada
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    Yes the hockey puck .. You said you read the posts about the subject , clearly you didnt as you would know what the hockey puck is .
    The 64 roars to life Whoo hoo ...shes a rolling chassis .
    You bend em" I"ll mend em" !!!!!!!
    I"m not a service tech.. I"m a thermodynamic transfer analyst & strategic system sustainability specialist
    Best Austin Healey In Show twice in 2013 .....All those hrs paid off .

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