Page 1 of 2 12 LastLast
Results 1 to 13 of 26
  1. #1

    Confused

    have a carrier 100 ton 30gt air cooled chiller. Another one of the techs was on the machine and determined that the B circuit EXV was bad. I returned to install the EXV. Replaced and pulled down to 400 microns, also replaced both saturated suction thermistor and suction gas thermistor.Started chiller and let run for 10 minutes, pressures 200/40 and slugging both B circuit compressors with liquid. As it turns out the same problem the first tech had. Unit it maintaining 27 degrees SH but shuts EXV all the way down to do it. Called factory and they suggested to recover charge and weigh in factory charge. Returned and recovered also drained 3 gallons of oil out of cooler, weighed in 105 lbs. of R-22 and started chiller let run and found pressures doing the same thing. I know the ciller does not care what the pressure are it will shoot to maintain 30 degrees SH. I have double and triple checked all my sensors and EXV and cable I am at a loss as to why the EXV is closing and still slugging liquid, sounds like a chainsaw on start-up

  2. #2
    Join Date
    Aug 2003
    Posts
    1,311
    three gallons of oil, holy crap, whats the 100 ton have three a circuit and two b cucuit? sound like alot of oil

    'maintains 27 degrees sh...still slugging" slugging what oil?

    if it sounds like a chain-saw during startup i'd be checking compressor vitals.

  3. #3
    Join Date
    Dec 2003
    Location
    Nevada
    Posts
    1,815
    Forgive my ignorance but is it a flowtronic chiller?
    Quote
    “Engineers like to solve problems. If there are no problems handily available, they will create their own." Scott Adams

    "We can't solve problems by using the same kind of thinking we used when we created them."
    Albert Einstein

  4. #4
    Join Date
    Aug 2003
    Posts
    242
    How is your water flow? Do you have air in the water loop?

  5. #5
    Join Date
    Feb 2003
    Location
    Wichita Ks
    Posts
    1,486
    you said your maintaining 27 degrees superheat and flooding at the same time. look in to the compressor, if it is running hot due to motor or hot gas dumping in to crankcase it will flood due to return gas sensor location. you might throttle the liquid line service valve down to stop the flooding so you can check the compressor out.

  6. #6
    Join Date
    Jul 2000
    Location
    Dallas,Texas
    Posts
    4,963
    Originally posted by hvacbear
    Forgive my ignorance but is it a flowtronic chiller?
    A chiller made by Carrier.
    Typically, multiple 06E compressors, electronic expansion valve(s) and a processor board to control it all.

    [Edited by wolfdog on 08-25-2004 at 09:37 AM]

  7. #7
    Join Date
    May 2004
    Posts
    205
    does carrier want 30 deg superheat????? seems awfully high! I thought the gt were looking for 8-10?, anyways, I've been pinched in the past with similar problems only to find out i missed the slightly plugged filter/dryer!

  8. #8
    Join Date
    Sep 2003
    Location
    Atlanta, GA
    Posts
    128

    You may have done all of this but here it is anyway.

    By all means get the oil back down to 1/3 sight glass.
    Too much oil screws up everything.
    Do you have record of oil added?
    The 06E may be pumping oil due to age or damage and someone kept adding. I've seen them pump it out as fast as it was added.
    Are you checking actual superheat with your thermometers or going by the chiller readout?
    Be sure no sensor cables are crossed.
    Check signal to EXV from processor board. 12 VDC pulsed signal to each winding. Or you can pump the circuit down, remove the EXV valve cover and go through the quick-test procedure to check EXV operation.
    I have seen EXVs drive one way but not the other.
    Water flow and chiller barrel condition (i.e. crushed tubes) can drive you nuts too.

  9. #9
    Join Date
    Feb 2003
    Location
    Wichita Ks
    Posts
    1,486
    carrier wants 30 degrees. this includes the heat of the motor thats why it is so high. if you check the suction line temp you will find the normal super heat is about where it shoul be

  10. #10
    Join Date
    Feb 2004
    Location
    Kentucky
    Posts
    100

    Hmm EXV problem

    Hello Tech.
    U need to check your fuse that supplies voltage to ypur EXV board, sure sounds like your EXV is 100% open and not shutting down. If there is voltage then the driver board could be bad but make sure voltage is at the valve!!!!

  11. #11
    flotronic chillers amintance around 30 degrees superheat which includes the superheat from motor windings. actual superheat is around 5 degrees depending on eprom chip.

    so how are you checking superheat by looking at the processor from a laptop or are you checking sat.suction temperture and suction line temp.

    flotronics run low superheat thats why they use exvs.
    electronic controls keep the superheat low. so if you have 27 degrees sh taken from suction gas thermistor minus sat.suction thermistor then your not flooding its designed for it. that means if you have a loud compressor then take heads off and check discharge and suction valves if ok then see if it will pump down if not change it.

  12. #12
    Join Date
    Jul 2004
    Location
    villalba,p,r
    Posts
    170
    The you tell me the you have there,200HP and 40LP and the system go down,in 10minute ok what reason the display indicate. my friend I thing 40 is to low.

  13. #13
    Join Date
    Dec 2003
    Location
    Nevada
    Posts
    1,815
    We had one similar problem changed the exv board and no problems since. The exv motor actually burned up.
    Quote
    “Engineers like to solve problems. If there are no problems handily available, they will create their own." Scott Adams

    "We can't solve problems by using the same kind of thinking we used when we created them."
    Albert Einstein

Page 1 of 2 12 LastLast

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