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  1. #14
    Join Date
    Jan 2010
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    In a Pineapple Under the Sea
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    149
    Quote Originally Posted by Doesn'tPhaseMe View Post
    At 11 pm your ice is gone and cw temp maybe 15 - 20f warmer putting more load on chiller at start up then.
    I meant chilled water not cond water.

  2. #15
    Join Date
    Oct 2004
    Location
    Metro ATL
    Posts
    454
    If you have a piston pressure increase while holding and you have already changed the load and unload solenoid valves, you might have an issue with the copper line that runs to the piston. The actual line itself runs inside the oil seperator enclosure so it is exposed to discharge pressure. It has flare fittings that connect it to the piston housing and to the internal line leading to the load and unload solenoids. If one of those is leaking, it will allow discharge pressure in and thus pressurize the load piston causing it to want to move toward the load position. If the leak is small enough, the unload solenoid may be able to bleed pressure fast enough so that it can unload but at a slower rate.

  3. #16
    Join Date
    Jan 2010
    Location
    In a Pineapple Under the Sea
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    149
    Quote Originally Posted by jemawalton View Post
    If you have a piston pressure increase while holding and you have already changed the load and unload solenoid valves, you might have an issue with the copper line that runs to the piston. The actual line itself runs inside the oil seperator enclosure so it is exposed to discharge pressure. It has flare fittings that connect it to the piston housing and to the internal line leading to the load and unload solenoids. If one of those is leaking, it will allow discharge pressure in and thus pressurize the load piston causing it to want to move toward the load position. If the leak is small enough, the unload solenoid may be able to bleed pressure fast enough so that it can unload but at a slower rate.
    I had 2 smaller 60hp screws on an RTWA (I think, I am bad with Tranes screw #'s) that both were doing the same thing. I actually had discharge pressure downstream of the unload solenoid. So they would actually load up when the unload solenoid was pulsed. Called Pueblo they had me put some other press taps to confirm what I was seeing. They had a aluminum manifold that gets bolted between the unloader solenoids and the compressor. No change to the load side but the unload side had a flare fitting now that gets piped into the suction line and the old port on the compressor is no longer used. It worked great.

  4. #17
    Join Date
    Mar 2004
    Location
    ottawa canada
    Posts
    2,111
    The parts that dont phase me is referring to is called a lip seal bypass kit . If the lip seal is leaking it allows discharge pressure to get behind the piston and cause the compressor to load without signals from the UCM. The kit re-routes this wayward gas directly back to suction faster than the lip seal can leak ,correcting the problem .
    Its a popular fix for the larger RTAA compressors .
    The toy chest is officially full ... I got a new toy..... 2007 Aston Martin V8 Vantage
    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 .

  5. #18
    Join Date
    Jan 2010
    Location
    In a Pineapple Under the Sea
    Posts
    149
    Quote Originally Posted by graham View Post
    The parts that dont phase me is referring to is called a lip seal bypass kit . If the lip seal is leaking it allows discharge pressure to get behind the piston and cause the compressor to load without signals from the UCM. The kit re-routes this wayward gas directly back to suction faster than the lip seal can leak ,correcting the problem .
    Its a popular fix for the larger RTAA compressors .
    Matter of fact it was made for a different compressor, they had me cut it in half because the bolt pattern was not the same so the pieces could be rotated into the proper position. I was the guniea pig for this according to Larry Volk in Pueblo.

  6. #19
    Join Date
    Dec 2008
    Location
    Vegas
    Posts
    3

    rthb150 unloading problem

    I am working on a rthb150 it does not appear to be unloading and has 22 starts in 4 hours

  7. #20
    Join Date
    Jul 2006
    Location
    The Great country of Texas
    Posts
    429
    This is a different problem but related to RTHB on ice storage. I had two RTHB300 on ice storage with UCP 2 on them. I had one hell of a time controlling the discharge gas superheat because it would load up so fast it drop the discharge superheat, close the EXV and cause it to go off on low evap because the ice building mode causes the slide valve go to 100% period. The way I fixed it was not to command the ice mode contact closure but tell the leaving chilled water sensor to make 15 degrees. This left all the slide valve pulsing in the equation but still made the left the safeties in because it would control off the low evap staging which would unload the slide. This way the exv had time to respond to the discharge gas temp. FYI, the chiller was not overcharged.
    Sorry for the rambling sentence...............
    "I'm from Texas, what country are you from?"

  8. #21
    Join Date
    Aug 2006
    Location
    Mixing oil and fire with a big spoon.
    Posts
    4,530
    Quote Originally Posted by Dan Espy View Post
    I am working on a rthb150 it does not appear to be unloading and has 22 starts in 4 hours
    ok. thanks for the heads up.
    "If you pull one more stunt like you just pulled with Tommy, you won't have to get on a plane because I will personally kick your ass from here to Korea!" - Best of the Best

  9. #22
    Join Date
    Dec 2008
    Location
    Vegas
    Posts
    3
    The only way I can keep this machine on for more than 15 min is to set my soft load cur limit rate to .06 and my soft load lvg water rate to 5, once I'm up to 45% exv opens up too much and drives my lwt down to 43 and shuts down. Why won't this thing stop loading? The discharge sh keeps over shooting the control point as well.

  10. #23
    Join Date
    Aug 2006
    Location
    Mixing oil and fire with a big spoon.
    Posts
    4,530
    we need a full set of readings (at least as many as you can get). also need teh setpoints in the chiller. there is a list in the IOM for you to write the values down.

    you may have a flow issue. there could be an unloading problem too. without all of the setpoints and the running values, it is difficult to figure it out.
    "If you pull one more stunt like you just pulled with Tommy, you won't have to get on a plane because I will personally kick your ass from here to Korea!" - Best of the Best

  11. #24
    Join Date
    Dec 2008
    Location
    Vegas
    Posts
    3

    p.i.a

    THIS IS HOW IT LOOKS RIGHT BEFORE SHUT DOWN
    EWT 52, EVAP LWT 46, COND EWT 80, COND LWT 87, SAT EVAP RFGT TEMP 42, EVAP RFGT PRESS 75, SAT COND TEMP 87, COND REF PRESS 160, COMP DISC TEMP 122 DISCH SUPERHEAT 34, DISCH SUPERHEAT CONTROL POINT 34, EXV POSITION 45.6%, EVAP APPRCH 2.4, COND APPRCH 0.0
    SERVICE SETTINGS ARE PRETTY CLOSE TO FACTORY SETTINGS THROUGHOUT
    ILL SEND OVER SETTINGS TOMORROW

  12. #25
    Join Date
    Aug 2006
    Location
    Mixing oil and fire with a big spoon.
    Posts
    4,530
    Quote Originally Posted by Dan Espy View Post
    THIS IS HOW IT LOOKS RIGHT BEFORE SHUT DOWN
    EWT 52, EVAP LWT 46, COND EWT 80, COND LWT 87, SAT EVAP RFGT TEMP 42, EVAP RFGT PRESS 75, SAT COND TEMP 87, COND REF PRESS 160, COMP DISC TEMP 122 DISCH SUPERHEAT 34, DISCH SUPERHEAT CONTROL POINT 34, EXV POSITION 45.6%, EVAP APPRCH 2.4, COND APPRCH 0.0
    SERVICE SETTINGS ARE PRETTY CLOSE TO FACTORY SETTINGS THROUGHOUT
    ILL SEND OVER SETTINGS TOMORROW
    without any other info, this chiller looks ok...the exv position might be a little far open...what was the %rla? got both gpm's? or at least ACCURATE pressure drops?
    "If you pull one more stunt like you just pulled with Tommy, you won't have to get on a plane because I will personally kick your ass from here to Korea!" - Best of the Best

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