Page 1 of 2 12 LastLast
Results 1 to 13 of 18
  1. #1
    Join Date
    Jun 2001
    Location
    Northwest Indiana
    Posts
    1,302

    30hxc screwy sounding screw compressor

    I pumped the unit down. i did let the crankcase go into a vacuum for a short period. Shut down unit and let the 30# cylindar empty into system via the liquid charging port on the bottom.
    when compressor started, its like a lagging almost low voltage sound\drone for about 3 sec and then takes off normal.
    Has anyone else experienced this?

    then next 3 starts thru out the morning all sounded normal.
    This happened on 2 diffent chillers today as i completed a leak check and repair on each. Systems are tight, 550 microns via my new JB digital vac guage, no leaks now
    If you cant fix it right, try again.

  2. #2
    Join Date
    Jan 2008
    Location
    Dallas ,Texas
    Posts
    3,707
    Was it a wye delta starter? Just FYI I would honestly NEVER EVER pumpdown a screw compressor .
    UA 100

    It takes three people to do anything around here. Two do the work, one explains to the crowd of people who showed up when they seen smoke and flames.

  3. #3
    Join Date
    Jun 2010
    Location
    U.A. (upper Alabama)
    Posts
    856
    Quote Originally Posted by toptech View Post
    I pumped the unit down. i did let the crankcase go into a vacuum for a short period. Shut down unit and let the 30# cylindar empty into system via the liquid charging port on the bottom.
    when compressor started, its like a lagging almost low voltage sound\drone for about 3 sec and then takes off normal.
    Has anyone else experienced this?

    then next 3 starts thru out the morning all sounded normal.
    This happened on 2 diffent chillers today as i completed a leak check and repair on each. Systems are tight, 550 microns via my new JB digital vac guage, no leaks now
    Like thegoodlistener said do not ever pump a screw down into a vac. or a scroll. The slide valve could have moved to the loaded position from the large delta p when you pumped it down into a vac. Pump it down to 40 psig and let your recovery machine do the rest. Just to be on the safeside.

  4. #4
    Join Date
    Jun 2001
    Location
    Northwest Indiana
    Posts
    1,302
    Quote Originally Posted by thegoodlistener View Post
    Was it a wye delta starter? Just FYI I would honestly NEVER EVER pumpdown a screw compressor .
    It wasn't intenional, I normally close off the liquid valve and stop the compressor just shy of vac, it got away from me.
    Ive only had to add refrigerant twice on these chillers. Whats the best way to charge?
    Thanks
    XL Start too
    If you cant fix it right, try again.

  5. #5
    Join Date
    Jun 2010
    Location
    U.A. (upper Alabama)
    Posts
    856
    Quote Originally Posted by toptech View Post
    It wasn't intenional, I normally close off the liquid valve and stop the compressor just shy of vac, it got away from me.
    Ive only had to add refrigerant twice on these chillers. Whats the best way to charge?
    Thanks
    XL Start too
    I never charge in the liquid line with liquid, unless I have pulled all of the gas out of the system and have saturation temp. well above freezing(if it's a chiller) with vapor. If you have enough gas in system to keep it from going out on low pressure, charge in comp. suction, on large compressors liquid through a 1/4" hose isn't going to hurt anthing as long as comp. is running.

  6. #6
    Join Date
    Oct 2006
    Location
    Central Texas
    Posts
    632
    Quote Originally Posted by toptech View Post
    It wasn't intenional, I normally close off the liquid valve and stop the compressor just shy of vac, it got away from me.
    Ive only had to add refrigerant twice on these chillers. Whats the best way to charge?
    Thanks
    XL Start too
    Charge how top off or full charge? From an evacuated system add vapor until ABOVE freezing, then flip it over and use liquid. Use charging valve out of EXV into evap. Flooded evap, you can top off charge same way.
    Sic Semper Tyrannis.

  7. #7
    Join Date
    Jun 2001
    Location
    Northwest Indiana
    Posts
    1,302
    Quote Originally Posted by txhvac View Post
    Charge how top off or full charge? From an evacuated system add vapor until ABOVE freezing, then flip it over and use liquid. Use charging valve out of EXV into evap. Flooded evap, you can top off charge same way.
    Thats what I has going to do and the carrier book said to use the liquid charging port! let me find the page, oops!
    3. Add 5 lb (2.3 kg) of liquid charge into the cooler using
    the 1⁄4-in. Schrader-type fitting located on the tube entering
    the bottom of the cooler. This fitting is located between
    the Electronic Expansion Valve (EXV) (size 076-
    146 units), or the economizer (size 161-271 units) and
    the cooler.

    Sheet, i read what I thought it said not actually what it said! I hate when that happens.
    Thats what I get for rushing, thanks guys for helping me think.
    If you cant fix it right, try again.

  8. #8
    Join Date
    Jun 2001
    Location
    Northwest Indiana
    Posts
    1,302
    Quote Originally Posted by txhvac View Post
    Charge how top off or full charge? From an evacuated system add vapor until ABOVE freezing, then flip it over and use liquid. Use charging valve out of EXV into evap. Flooded evap, you can top off charge same way.
    This was a top off charge, i had water running thru the barrel. I got it half right
    If you cant fix it right, try again.

  9. #9
    Join Date
    Jun 2010
    Location
    U.A. (upper Alabama)
    Posts
    856
    Quote Originally Posted by toptech View Post
    This was a top off charge, i had water running thru the barrel. I got it half right
    I never, repeat never, rely on having water flow through barrel when charging with liquid. Always looking look at saturation temp. make sure it's well above freezing. Because what if one, just one, tube is stopped up.

  10. #10
    Join Date
    Jun 2001
    Location
    Northwest Indiana
    Posts
    1,302
    Quote Originally Posted by cperk View Post
    I never, repeat never, rely on having water flow through barrel when charging with liquid. Always looking look at saturation temp. make sure it's well above freezing. Because what if one, just one, tube is stopped up.
    Step 7 Refrigerant Charge
    NOTE: The liquid charging method is recommended for
    complete charging or when additional charge is required.
    When charging, circulate water through the condenser and
    cooler at all times to prevent freezing. Freezing damage is
    considered abuse and may void the Carrier warranty.

    True, but I did follow those instuctions!
    If you cant fix it right, try again.

  11. #11
    Join Date
    Aug 2000
    Location
    USA
    Posts
    4,990
    Totaly agree, always vapor until at least 40F sat temp on water, possibly lower on glycol.
    Quote Originally Posted by cperk View Post
    I never, repeat never, rely on having water flow through barrel when charging with liquid. Always looking look at saturation temp. make sure it's well above freezing. Because what if one, just one, tube is stopped up.
    Your poor planning does not constitute an emergency on my part!!!!

  12. #12
    Join Date
    Jan 2009
    Location
    Not in Iran
    Posts
    1,091

    Talking

    Quote Originally Posted by cperk View Post
    I never, repeat never, rely on having water flow through barrel when charging with liquid. Always looking look at saturation temp. make sure it's well above freezing. Because what if one, just one, tube is stopped up.
    perk, wow just one tube can cause serious problems huh., i understand that want to run water through barrols and want to charge w vapor until saturation is about 40*, can u explain y just one tube can cause such a problem? thanks
    no signature blast'em man blast'em
    !!!KILL THE TERRORIST!!!

  13. #13
    Join Date
    May 2008
    Location
    Central Pennsylvania
    Posts
    441
    Quote Originally Posted by mlkwal1 View Post
    perk, wow just one tube can cause serious problems huh., i understand that want to run water through barrols and want to charge w vapor until saturation is about 40*, can u explain y just one tube can cause such a problem? thanks
    If you have a tube which is blocked you now have no flow through that tube. That is why it's recommended to charge with vapor until above 40* saturation temp, so that you know there won't be any chance of freezing the water in said blocked tube.

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