Page 2 of 2 FirstFirst 12
Results 14 to 22 of 22
  1. #14
    Join Date
    Aug 2008
    Posts
    322
    You stated that the second comp never did come on line I have a 80 ton screw chiller {Trane} that i take care of I have in the past put #one comp. into alarm then in afew minutes the second comp. come on line you might try this let it get the water temp down then see if the other comp. will come in and stay on line.

  2. #15
    Join Date
    Oct 2001
    Posts
    6,945
    OK its an air cooled chiller with semi-hermetics and a W7900 controller for chilled water controlling.first thing your doing is load limiting with 100F water entering that barrel #1 and #2 2 red leds per compressor on the W7900.then the leds change to #2 and #3 on each circuit LTC overlap shutdown.the unit only has 1 sensor on chilled water out.the sensor resistance range is 90F/3516.2 ohms 80F/3498.2 ohms 70F/3450.0 ohms 50F/3353.4 ohms.how are those settings on the W7900???? for now set them higher on *leaving fluid for now to 70F *10F on design d/t *number of stages is the total on the W7900 probably 6.toggle off one circuit and let that get the chilled water down to normal operating return temps 70F/80F...your banging that evap barrel at 30F drop on the water in and out.don't add gas or touch the TXVs just run that single stage first...100F water into the unit your suction must be up there also...go for a longer run with less tonnage till that return water and suction get down to cool the compressor.load limiting will not allow the 2nd circuit to run until it drops below 56F on the water out..why your running both circuits on STARTS there might be the settings on the W7900.work the fluid setting from 80 to 70 to 60 to 50 don't force the chiller stay within that 10 design delta T on that barrel 30F the chiller is flippin out 100F entering is not normal get the loop temp down slowly then toggle in that other circuit.
    "when in doubt...jump it out" http://www.youtube.com/watch?v=U1qEZHhJubY

  3. #16
    Let me go double check gauges. I am also going to hydrometer test and verify the glycol conceration. I am on the phone with one of our 30yr veterans and he said that we have recently added a modulating valve to the intake or discharge because the chiller was making the coffee concertrate 40 degrees. I will go check gauges and this modulating valve and I will back in about 10 minutes.

  4. #17
    Join Date
    Sep 2008
    Location
    New Kensington, Pa.
    Posts
    6

    CGAC Trane

    The leaving water sensor 4RT1 sits on top of the evaporator right above the leaving water connection. You should see the SO cord going to the insulated "bump" on the top. The Referteacher has a good point, I don't know what options your chiller has but minimum starting ambients are 45 degrees with hot gas bypass, and 35 without it. If you have a low ambient damper option then that is the only fan that should be operating, and that would give you sarting capabilities down to 0 - 10 degrees. You have what is called an "Inverted Start" with the cool ambient and high load. I agree, don't be afraid to pull the contactor coil wire off of the fans. Be careful, shocks hurt worse in the dark. A switched jumper will allow to control the condenser fan and maintain a desired higher head. If it trips again on a LTC diagnostic, IMMEDIATELY pull the sensor wires at the 1U12 controller and ohm them. IF you really are tripping on freeze you will have a very low ohm reading at the sensors wires, like 3,200 ohms or lower. What is your saturated suction temp??

  5. #18
    Join Date
    Sep 2008
    Location
    Pittsburgh,PA
    Posts
    63
    this is your friendly spelling bee cvhcr1...........starting not sarting.

  6. #19
    Join Date
    Sep 2008
    Location
    New Kensington, Pa.
    Posts
    6

    Bowhunter

    Hi D. Man, I hate getting stung by the spelling bee !!!

  7. #20
    Join Date
    Oct 2001
    Posts
    6,945
    you said that your modulating the return and or the supply water thru the machine..you have to be by-passing the water back or the flow switch will pick it up or your barrel will trip on LTC with lesser flow.your original post here said you had 100F entering and 70F leaving with one compressor running for 20 minutes..i would get away from the control room readings????and get your readings off the chiller water entering/leaving thermometers.
    "when in doubt...jump it out" http://www.youtube.com/watch?v=U1qEZHhJubY

  8. #21
    Join Date
    Sep 2008
    Location
    Texas
    Posts
    371
    Sounds to me like he is bypassing water around the chiller with his new bypass valve.
    "Dying aint much, its living thats hard." (Josey Whales)

  9. #22
    Join Date
    May 2006
    Location
    N.E. IA
    Posts
    512
    Hey, CHEESETECH. Did you ever get your chiller running the other night? Those of us who stayed up past our bedtime would like to know if we were of any help. We'd all like to know what exactly your situation was and what you did to finally get it going. Of course, by the next day, the weather warmed up and it probably is running just fine, now.
    "Wheel" mechanics work on "Wheel" chillers

Page 2 of 2 FirstFirst 12

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