Results 1 to 11 of 11
  1. #1

    RTAAO8O Low Evap Temp

    Trane RTAA0804XLO1A30CB S# U00508585
    Trips on Low Evap Temp,not on initial start-up but after unit approaches set point and unloads then when it loads up again it jumps fron 48% to 98% and the suction pressure drops around 28psi and the Evap Temp sensor reading also drops to 17 degrees and locks out

  2. #2
    Join Date
    Aug 2008
    Location
    Pgh, Pa.
    Posts
    18
    Check the load signal and the load solenoid. May have a faulty valve.
    I reckon so.

  3. #3
    Join Date
    Mar 2005
    Location
    CHATTANOOGA, TN.
    Posts
    150
    They are 3 things that i can think of:

    1 unloader valve problem(could be strainer under valve body)

    2 load sol valve stuck open.

    3 low cw water.

  4. #4
    Join Date
    Oct 2004
    Location
    Metro ATL
    Posts
    454
    Sounds like the piston is sticking. The load solenoid continues to apply pressure gradually until it builds up enough for it to move and then Whamo!

  5. #5
    Quote Originally Posted by jemawalton View Post
    Sounds like the piston is sticking. The load solenoid continues to apply pressure gradually until it builds up enough for it to move and then Whamo!
    THE MALE UNLOADER PISTON

  6. #6
    Join Date
    Oct 2004
    Location
    Metro ATL
    Posts
    454
    You lost me on that one. I am refering to the piston upon which the load and unload soleniod valves apply pressure in order to cover or uncover more of the rotors in order to load and unload the machine. Check the pressure on the piston as it relates to the actions of the load and unload soleniod valve.

  7. #7
    Join Date
    Mar 2008
    Posts
    71

    tried and true technical term

    Quote Originally Posted by jemawalton View Post
    Sounds like the piston is sticking. The load solenoid continues to apply pressure gradually until it builds up enough for it to move and then Whamo!
    Whamo-Tried and true technical term

  8. #8

    Smile

    Thanks Guys for all your support,this is a great site to ba able to access:

  9. #9
    Dunno if you got it workin or not.....

    I had a RTAA300 doing the same thing on one of the circuits. Check the temp sensors. Mine were close, but when the approached setpoint temps were like 5 degrees and circuit locked out on low evap temp.

    My RTAA had to run a while after start up before it would do this.

  10. #10

    rtaa & trane

    Had one doing this and low oil. only when outside temp changes. Never had any training on it, man. says clean coils and the charge was wrong. I said dirty oil filter. After several days of many people scratching heads. I pumped machine down changed filter ( man. said filter should never need changing ) Unit has been running fine for 2 years. Oh yea man. said other side slide valve was bad filter also.

  11. #11
    Join Date
    Sep 2008
    Location
    Delaware
    Posts
    243
    Check the thermistors for proper values/readings. If in doubt strap a thermistor on the suction line (10,000 ohm @77 degrees F) and temporarly wire it in for a check. That is pretty much the standard sensor all over that machine.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event