Results 1 to 9 of 9
  1. #1
    Join Date
    May 2012
    Location
    Fort Worth TX
    Posts
    7

    Trane air cooled chiller with low suction temp alarm

    Hey guys and gals new to the site, I was hoping I can get some insight on a Trane Air Cooled Chiller. M#CGAM052A202..... S#U10F16517, unit is 410a refrigerant. Has a CH530 controller on it. Unit has 4 scroll compressors, EXV's, and four condenser fan motors. Unit is fairly new as you can see from the serial # . OK so whats happening is the chiller goes to a low suction temperature alarm kind of randomly during the week. And from what I can see on the alarm history it's always the the Lag circuit that goes into alarm. So I'm getting these alarms on both circuit 1 and circuit2. Units running good as far as refrigerant pressures and temps, superheat and sun cooling are pretty much dead on. Whats throwing me off is its only on the circuit thats the lagging circuit. Anyways guys I hope this is enough information to try and get some insight on the chiller. BTW the suction temperature sensor was changed on circuit 2 a couple of day ago by a co-worker. Any information would be greatly appreciated .

  2. #2
    Join Date
    Jul 2007
    Location
    The Hot South
    Posts
    1,310
    Check the pressure transducer and temp sensor accuracy, make sure temp sensors are inserted all the way in the wells, check water flow, & check flow switch

  3. #3
    Join Date
    May 2012
    Location
    Fort Worth TX
    Posts
    7
    We did check the accuracy of the sensors and that's what led to us changing circuit 2's sensor. The unit has a plate heat exchanger on it, with a strainer right in front of it. We already pulled the strainer out verified the strainer to be clean. A co-worker and I discussed the flow switch, but decided that the CH530 would have given us a loss of flow alarm. I did verify that the flow switch was working. So I'm gonna keep trying to see if I can figure out what's causing the unit to give us the Low Suction Temperature Alarm. Thanks for your input R123.

  4. #4
    Join Date
    Nov 2007
    Location
    Mississippi
    Posts
    1,337
    When you verified the flow switch was working, did you verify it would close and open? Do you have enough loop capacity for this chiller? Maybe it can't unload fast enough when it's close to setpoint.

  5. #5
    Join Date
    May 2012
    Location
    Fort Worth TX
    Posts
    7
    When I showed up yesterday, I turned the unit off and hooked up TechView. When turned it back on I had no flow, went down to the pump room and had to reset the starter for the chill water pump. That's as far as I went with the flow switch. I the chiller has been running for almost 2 years with no problems. I believe when the chiller was replaced we went ton for ton. Im confident nothing has changed in the building. And I believe the CH530 decides how it needs to load up and unload. But I will check and see if there is a temperature differencial that's adjustable for loading and unloading. Thanks for your input socotech

  6. #6
    Join Date
    Nov 2007
    Location
    Mississippi
    Posts
    1,337
    Are there any strainers at the chill water pump(s)? Sounds like it could be low flow. Are there pressure gauges on water loop?

  7. #7
    Join Date
    Jul 2007
    Location
    The Hot South
    Posts
    1,310
    Quote Originally Posted by Er14ic View Post
    When I showed up yesterday, I turned the unit off and hooked up TechView. When turned it back on I had no flow, went down to the pump room and had to reset the starter for the chill water pump.
    Sounds like you found your problem.

  8. #8
    Join Date
    Apr 2012
    Location
    lexington, NC
    Posts
    32
    You need to check you loop gpm. The min on a cgam chiller is 102gpm. I had the same problem with one. They had the pumps set up for the air handlers which was 92 gpm.

  9. #9
    Join Date
    Jun 2006
    Location
    midwest
    Posts
    122

    CGAM

    CHECK YOUR CHILLED WATER SUPPLY,SOUNDS LIKE LOW ON FLOW. ENOUGH FOR 1ST STAGE NOT ENOUGHFOR 2ND STAGE.CHECK YOUR EXPANSION TANK, I BET ITS EMPTY,PROBABLY IN A VACUUM

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