Results 1 to 13 of 13
  1. #1
    Join Date
    Jun 2020
    Posts
    6
    Post Likes
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Frown Carrier 5H80 unstable loading and unloading sequence

    Recently overhauled a carrier 5H80 due to inability to unload. Application is for AC using R-404a, condenser is fresh water cooled. During the overhaul, found the usual problems. broken unloader forks and some broken piston rings. This compressor had 26,000 hours on it and I have no idea when it was last overhauled.

    Changed out Con Rod bearings, piston rings, all unloader power elements, and flipped over suction ring valves. Discharge valves were inspected and in good condition. Ran compressor with valve plates and heads off and adjusted the capacity control external adjusting stem to verify all power elements were working. Capacity control end cover was removed and inspected. Control oil strainer was removed and observed to be clean.

    Everything put back in place and system is charged up. Compressor started up and loaded to 100%. slowly turning adjusting stem CW to unload and set control point. 1st sage unloads, then 2nd (3 cylinders total). At this point suction pressure is 64 psig (26 F). A quarter turn more to get the 3rd stage, and this is where the problems starts. 3rd stage unloads, and within 1 second the 4th stage unloads. Suction pressure rapidly swings to 105 psig (50 f) and then 4th stage loads, and again within a second the 3rd stage, then 2nd stage, then 1st now running at 100%. Suction pressure swings low to 44 psig (10 F) then 1st stage unloads, suctions pressure slowly increases, the 2nd, and then when the suction pressure continues to climb the same rapid 3rd and 4th stage unloads and the process repeats.

    This is driving me crazy, I've already changed out the capacity control end cover out with a new one, and still had the same result. I've also taken off all the headcovers and valve plates and tested the unloaders again. The pneumatic port is unobstructed and vented to atmosphere, control oil strainer is fine. Difference between suction pressure and oil pressure is approx 45 psi, so I know the oil pressure regulator is fine as well.

  2. #2
    Join Date
    Mar 2010
    Location
    Sunny SoCal
    Posts
    408
    Post Likes
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

  3. #3
    Join Date
    Jun 2020
    Posts
    6
    Post Likes
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Thread Starter
    I thought it might be the hydraulic relay until we replaced the entire capacity control unloader end cover with a new one. Any other ideas?

    I'm thinking it might be a slight blockage in the line that goes to the capillary, which is connected to the surge chamber

  4. #4
    Join Date
    Mar 2008
    Location
    kansas
    Posts
    1,811
    Post Likes
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    You might try emailing remanworld ray is very knowledgeable I don’t think he’s been on since the crash
    Honeywell you can buy better but you cant pay more

    I told my wife when i die to sell my fishing stuff for what its worth not what i told her i paid for it

  5. #5
    Join Date
    Jun 2020
    Posts
    6
    Post Likes
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Thread Starter
    Thanks, I'm new to the forum. How do I get in contact with remanworld ray?

  6. #6
    Join Date
    Mar 2008
    Location
    kansas
    Posts
    1,811
    Post Likes
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by MarineEngineer View Post
    Thanks, I'm new to the forum. How do I get in contact with remanworld ray?
    Hit the search button enter his username then look at his profile for his email address or post your email in your profile and I will send it to you. No emails in threads per site rules
    Honeywell you can buy better but you cant pay more

    I told my wife when i die to sell my fishing stuff for what its worth not what i told her i paid for it

  7. Likes MarineEngineer liked this post.
  8. #7
    Join Date
    Jun 2020
    Posts
    6
    Post Likes
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Thread Starter
    Got it. Thanks for the tip!

  9. #8
    Join Date
    Aug 2010
    Location
    Dearborn MI
    Posts
    409
    Post Likes
    Mentioned
    0 Post(s)
    Tagged
    1 Thread(s)
    All four stages of unloading work so you can rule out the hydraulic relay. They just aren't responding correctly to suction pressure which usually means that the cap tube to the surge chamber is loose or broken, but you changed the end bell. What does that leave? The range adjustment spring behind the adjustment nut. There are two springs, do you have the correct one installed?

  10. #9
    Join Date
    Mar 2008
    Location
    kansas
    Posts
    1,811
    Post Likes
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Good to see you back
    Honeywell you can buy better but you cant pay more

    I told my wife when i die to sell my fishing stuff for what its worth not what i told her i paid for it

  11. #10
    Join Date
    Aug 2010
    Location
    Dearborn MI
    Posts
    409
    Post Likes
    Mentioned
    0 Post(s)
    Tagged
    1 Thread(s)
    [QUOTE=MarineEngineer;25888539]Recently overhauled a carrier 5H80 due to inability to unload. Application is for AC using R-404a, condenser is fresh water cooled. During the overhaul, found the usual problems. broken unloader forks and some broken piston rings. This compressor had 26,000 hours on it and I have no idea when it was last overhauled.

    Changed out Con Rod bearings, piston rings, all unloader power elements, and flipped over suction ring valves. Discharge valves were inspected and in good condition. Ran compressor with valve plates and heads off and adjusted the capacity control external adjusting stem to verify all power elements were working. Capacity control end cover was removed and inspected. Control oil strainer was removed and observed to be clean.

    Everything put back in place and system is charged up. Compressor started up and loaded to 100%. slowly turning adjusting stem CW to unload and set control point. 1st sage unloads, then 2nd (3 cylinders total). At this point suction pressure is 64 psig (26 F). A quarter turn more to get the 3rd stage, and this is where the problems starts. 3rd stage unloads, and within 1 second the 4th stage unloads. Suction pressure rapidly swings to 105 psig (50 f) and then 4th stage loads, and again within a second the 3rd stage, then 2nd stage, then 1st now running at 100%. Suction pressure swings low to 44 psig (10 F) then 1st stage unloads, suctions pressure slowly increases, the 2nd, and then when the suction pressure continues to climb the same rapid 3rd and 4th stage unloads and the process repeats.

    This is driving me crazy, I've already changed out the capacity control end cover out with a new one, and still had the same result. I've also taken off all the headcovers and valve plates and tested the unloaders again. The pneumatic port is unobstructed and vented to atmosphere, control oil strainer is fine. Difference between suction pressure and oil pressure is approx 45 psi, so I know the oil pressure regulator is fine as well.[/Q

    Re-reading this it occurs to me that you may not be adjusting the unloaders correctly. If your suction pressure is above the desired control point you lower the pressure by slowly closing the suction service valve until the control pressure is reached. Then you turn the stem CW until the first step of unloading takes place. That's it. The remaining steps follow automatically as determined by the hydraulic relay. The compressor will be fully loaded when the suction pressure is 4 psig above the suction pressure with R22 and fully unloaded when the suction pressure is 7 psig below the control set point. I think that you are turning the adjustment stem too much.

  12. Likes BBeerme, slctech, crazzycajun liked this post.
  13. #11
    Join Date
    Mar 2008
    Location
    kansas
    Posts
    1,811
    Post Likes
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Hopefully the op will get back to us if not sorry for interrupting your day to day ray I always learn something from your posts
    Honeywell you can buy better but you cant pay more

    I told my wife when i die to sell my fishing stuff for what its worth not what i told her i paid for it

  14. #12
    Join Date
    Jun 2020
    Posts
    6
    Post Likes
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Thread Starter
    Thanks for all the help guys, Happy Fourth of July. The unit is installed onboard a ship and we have been dealing with the ships other systems as we have an inspection coming up. We have two compressors, and the other is working fine so that project got put on the back burner.

    -Remanworld
    I have the correct range spring( 10 lb for R22 / R404a), didn't put it in my post but that was one of the first things I changed. Always do the easiest thing first right. We have the oil drained so we're going to remove the end cover and inspect the connection between the capillary and surge chamber, and also look at it where it lines up with the oil pump flange ports. I mentioned we changed the end cover with a new one, but it was a spare we had onboard and we had to move the copper tubing around a bit and push on the hydraulic relay to get it to fit up without the tubing preventing us from bolting up the end cover. Is that normal for a new part? I have no idea where it came from, maybe it's a foreign knockoff it that's a thing. I think we got it in Egypt, so it's anyones guess.

    Also you are correct I'm not adjusting the unloader as you stated and as per the manual. I can never get my suction pressure above my desired control point 72 psi (32F) when the compressor is at 100% So what I have done in the past is slowly turn the stem CW until the compressor unloads and suction pressure reaches steady state condition. Then continue to turn CW and repeat until the suction pressure settles in at 70-80 psi. While this may be wrong it is how I set the other unloader for the compressor that is running now. When I first got to this ship the evap was constantly icing and I found that the both compressors were running 100% with low suction pressure this was the solution after checking all the other things.

    Gunna get after it on Wednesday I'll let you know the results. Thanks again

  15. #13
    Join Date
    Jun 2020
    Posts
    6
    Post Likes
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Thread Starter
    Oh and before you ask. TXV are newish (1 year), no obstructions or problems with orifices, bulbs is good. Evap is clean, airflow is good.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Contracting Business
HPAC Engineering
EC&M
CONTRACTOR