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  1. #1
    Join Date
    Sep 2002
    Posts
    12,195

    Dunham Bush Vertical / Medium screw compressor

    This is a 1215NHF compressor.

    Has any one ever done a J Version to K Version compressor upgrade / changeout?

    And can tell me what's involved?

    For example; is the J suction service valve the same size as the K discharge service valve?

    What exactly is different? What needs to be altered on the chiller package to install the new K in place of the original J?
    PHM
    --------
    The conventional view serves to protect us from the painful job of thinking.

  2. #2
    Join Date
    Aug 2000
    Location
    USA
    Posts
    4,986
    Yes, PITA. In order to get electric to line up you need to cutoff discharge lines and suction lines close cooler and cond and repipe. Feet don't line up with old style, had to have a plate made. We put valves and a discharge check valve on the new compressor. Pulled out inline cv. Electric is all the same.

    Have you put the modified oil recovery system on the chiller? Now would be the time to do it if you have the gas out of the chiller. Eliminated all the low oil service calls.
    Your poor planning does not constitute an emergency on my part!!!!

  3. #3
    Join Date
    Sep 2002
    Posts
    12,195

    Let's talk some more -

    I know that the suction flange is 90 degrees around the housing on the K but isn't that just some 3" copper and a 90 to make it fit?

    Same with the electrical - just extend the 3" Greenfield tom the new control box and run longer wires?

    Why did you use service valves And a discharge check valve? Isn't the suction check enough to prevent backspin? Did you have another reason to add the discharge check?

    What version was your unit? What in-line check valve did you remove?

    What is the modified oil recovery system?

    These B generation units have a single outlet at each end of the flooded chiller barrel at about the five o'clock position. They are connected by a 5/8" line which tees up into the bottom of the jet pump.

    I started dozens of them in the 1980's - what low oil service calls? I really never had a problem with that.

    Can either of the present J service valves be re-used on the K compressor?

    PHM
    -----------



    Quote Originally Posted by absrbrtek View Post
    Yes, PITA. In order to get electric to line up you need to cutoff discharge lines and suction lines close cooler and cond and repipe. Feet don't line up with old style, had to have a plate made. We put valves and a discharge check valve on the new compressor. Pulled out inline cv. Electric is all the same.

    Have you put the modified oil recovery system on the chiller? Now would be the time to do it if you have the gas out of the chiller. Eliminated all the low oil service calls.
    PHM
    --------
    The conventional view serves to protect us from the painful job of thinking.

  4. #4
    Join Date
    Aug 2000
    Location
    USA
    Posts
    4,986
    I'll get back to you on model number, it's in the truck. It was a ''B'' style if Im not mistaken, PCWB 260 maybe.

    Compressor is taller, discharge line won't reach top of screw. Suction is 90degrees off. Electric fit fine. Check valve was in discharge line. Not sure if the valves fit, never looked due to repiping needed.
    Your poor planning does not constitute an emergency on my part!!!!

  5. #5
    Join Date
    Dec 2005
    Location
    Rockhill South Carolina
    Posts
    370
    Rip em out put in some copeland scrolls and microtech 2 worked great on a 110 ton IACDX that was oversized for the load and D&B controls dead!

  6. #6
    Join Date
    Sep 2002
    Posts
    12,195

    Will you pay for it?

    Because they sure won't.

    My plans for this customer for the future are some three-compressor or four-compressor recip packages with no unloaders, across-the-line starting, and all electro-mechanical controls.

    The Carrier screw is going for scrap this spring, and the York centrif. will be right behind it next year. This job is going to get equipment with some redundancy and that anybody can fix.

    But my present directive is: give us cooling at the least cost. So I'm replacing the two vertical screws.

    PHM
    -----------


    =captinsano;2022890]Rip em out put in some copeland scrolls and microtech 2 worked great on a 110 ton IACDX that was oversized for the load and D&B controls dead!
    PHM
    --------
    The conventional view serves to protect us from the painful job of thinking.

  7. #7
    Join Date
    Aug 2000
    Location
    USA
    Posts
    4,986
    Then sell them 2 Hanbells with the MSC controller. They come with a 3 year warranty if you put the MCS controller. Your sure not going cheap by putting in 2 POS Hartford vertical screws. JMHO
    Quote Originally Posted by Poodle Head Mikey View Post
    Because they sure won't.

    But my present directive is: give us cooling at the least cost. So I'm replacing the two vertical screws.

    PHM
    -----------
    Your poor planning does not constitute an emergency on my part!!!!

  8. #8
    Join Date
    Sep 2002
    Posts
    12,195

    How much would the Hanbells be?

    Are you saying that the Hanbells would cost less even with all the altered mounting and repiping and whatever else is required to retrofit them in place of the VSC's?

    PHM
    ----------



    Quote Originally Posted by absrbrtek View Post
    Then sell them 2 Hanbells with the MSC controller. They come with a 3 year warranty if you put the MCS controller. Your sure not going cheap by putting in 2 POS Hartford vertical screws. JMHO
    PHM
    --------
    The conventional view serves to protect us from the painful job of thinking.

  9. #9
    Join Date
    Aug 2000
    Location
    USA
    Posts
    4,986
    You could probably get the 2 Hanbells and the controls for around the price of one Hartford. http://www.mcscontrols.com/ heres the rep. Call and get pricing.
    Your poor planning does not constitute an emergency on my part!!!!

  10. #10
    Join Date
    Sep 2008
    Location
    Mesquite Tx.
    Posts
    368
    Hear good things about the hanbel. Prices are good, probably more reliable. Also repairable.

  11. #11
    Join Date
    Dec 2007
    Location
    Southern, CA
    Posts
    520
    About the low oil, if his experience is similar to mine, it usually happens under low load conditions. When all compressors are running, oil is returned to all. But when one or more shut down, the oil that would have gone to the now idle compressor, may instead end up in the still running one(s). If it runs long enough this way, when the last stage compressor fires up again, it's low on oil, the factory oil transfer is too slow, and it shuts down on low oil safety.

    I made an oil equalizer by plugging a 1/4 ball valve into the side of the sight glass housing at the normal oil level, and connected to the other compressors by 1/4 tubing and similar valves. This way normal levels are maintained whether running or not. The factory sells a kit if you want to spend a grand or more for it.

    You might want to consider installing something similar while you've got it torn up.

  12. #12
    Join Date
    Sep 2002
    Posts
    12,195

    But it's a PCWX-150

    Which has a single VSC compressor. <g>

    PHM
    --------




    Quote Originally Posted by Coolmaniac View Post
    About the low oil, if his experience is similar to mine, it usually happens under low load conditions. When all compressors are running, oil is returned to all. But when one or more shut down, the oil that would have gone to the now idle compressor, may instead end up in the still running one(s). If it runs long enough this way, when the last stage compressor fires up again, it's low on oil, the factory oil transfer is too slow, and it shuts down on low oil safety.

    I made an oil equalizer by plugging a 1/4 ball valve into the side of the sight glass housing at the normal oil level, and connected to the other compressors by 1/4 tubing and similar valves. This way normal levels are maintained whether running or not. The factory sells a kit if you want to spend a grand or more for it.

    You might want to consider installing something similar while you've got it torn up.
    PHM
    --------
    The conventional view serves to protect us from the painful job of thinking.

  13. #13
    Join Date
    Dec 2007
    Location
    Southern, CA
    Posts
    520
    Sorry, didn't see it mentioned, fake it out and pipe it back to itself.

    If I can't dazzle em' with brilliance...............................

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