• Refrigeration Briefs

    June 1, 2012
    A conference on refrigerants hosted by ASHRAE and the National Institute of Standards and Technology (NIST) has been announced for October 2012.

    ASHRAE/NIST Conference Set for October; Focus on Sustainability
    A conference on refrigerants hosted by ASHRAE and the National Institute of Standards and Technology (NIST) has been announced for October 2012.

    “Moving Toward Sustainability” takes place Oct. 29 - 30, 2012, at NIST in Gaithersburg, MD. The conference features papers from leading global experts on a broad range of topics, including the status of current environmental, scientific, and regulatory activities. For additional information, visit http://bit.ly/ashraenist.

    Purdue’s Herrick Conferences Due Up in July; Includes Buildings
    The 21st International Compressor Engineering Conference, the 14th International Refrigeration and Air Conditioning Conference, and the 2nd International High Performance Buildings Conference will take place July 14-19, 2012 on the campus of Purdue University, West Lafayette, IN. The 2012 Compressor Engineering Conference will include sessions on specific compressor technologies such as reciprocating, rotary, scroll, screw, centrifugal, linear and novel compressors.

    The Refrigeration and Air Conditioning Conference will explore heat transfer and fluid flow fundamentals, alternative refrigerants and working fluids, and more. The High Performance Building Conference will cover building envelope systems, indoor environment and air quality, and more. Visit http://bit.ly/purdueconferences for additional information.

    Carrier Symposiums Continue
    Carrier’s Sustainability Symposium series will appear in Philadelphia, PA on June 13, and Bethesda, MD, on Sept. 17. The Symposiums will provide consulting engineers, Design/Build contractors, and facility managers with a one-day course on emerging trends and technologies associated with sustainable, high-performance buildings, as well as continuing education credits. The symposiums promote environmentally responsible buildings of the future and feature a hands-on look at Carrier’s Mobile Innovation Center, an 18-wheel trailer featuring the company’s sustainable products and energy service offerings. For additional information, visit carrieruniversity.com.

    INSTALLATION TIP: Compressor Installation & Start-Up

    Before Start-Up

    • Follow safe and proper installation practices according to operating and installation manuals and service technician industry standards.
    • Try to determine why the previous compressor failed or the replacement compressor may fail for the same reason (even on start-up). If possible, obtain an analysis of the failed compressor. Replace any suspect contactors and double check the wiring and jumpers.
    • Install new liquid and suction line dryers.
    • Ensure that your oil is not exposed to moisture, and charge the compressor so the oil is visible in the sightglass.
    • Pull the system down to an appropriate vacuum. Leak check with dry nitrogen (obey the maximum pressure rating on the compressor data tag).
    • The crankcase heater needs to heat the oil to at least 30-40 degrees warmer than the ambient temperature prior to refrigerant charging.
    • Properly charge the system: liquid into the receiver or condenser, and vapor only into the suction of the compressor, while running.

    At Start-Up

    • For screw compressors and scroll compressors, be sure to bump-start the compressor to verify rotation. To reduce the initial motor load and the risk of slugging, crack open the suction valve and then slowly open as system pulls down.

    After Start-Up

    • After 15-30 minutes, the oil should have little foam and the level should be near the middle of the sightglass.
    • Inspect the oil to see if burned or dirty oil is returning to the compressor. Sample, test, and change out the oil as much as needed until it is clean.
    • Verify oil pressure and suction superheats match the compressor recommendations.
    • Verify the expected amp draw and discharge temperature per the compressor software.
    • Fill out a start-up sheet to confirm and preserve your system measurements.

    NOTE: Italics refer to replacing a failed compressor.

    Source: Thomas Olejniczak, Product Marketing, Bitzer US. bitzerus.com