Common Guidelines For Optimum Chiller Performance

  1. Maintain Equipment operating logs
  • Logs should be filled out twice during each 8-hour shift
  • Record pressures, temperatures, and other pertinent information to recognize performance

2. Follow proper compressor shutdown and startup routines.

  • Follow manufacturer recommended shutdown procedures
  • Components that may need attention are the compressor, compressor motor, control center, purge
    unit, oil return system, cooler, condenser, starter, and water pumps
  • Follow OSHA lockout/ tagout regulations

3. Check chiller control center and starter for proper operation

  • Proper electrical overload settings
  • Chiller shuts off promptly due to excessive amperage
  • Check all starter wire connections for loose contacts, obstructions, or pitting
  • Electronic controls for motor current limit, overload, power fault interruption, and pre-rotation vane
    control (centrifugal chillers) should be tested

4. Perform oil sampling and analysis

  • Oil analysis provides unambiguous evidence of chiller condition
  • High copper levels indicate tubing corrosion, or oil pump bearing wear
  • HVAC manufacturers recommend annual oil sampling and filter inspection

5. Keep Refrigerant clean and charged

  • Condenser and evaporator shells become subject to corrosion
  • Rust can settle in condenser shell, mix with oil, and become sludge
  • Sludge-covered tubes reduce heat-transfer efficiency, raising energy consumption

6. Eliminate Condenser tube scale

  • Excess head pressure caused by scale makes the compressor work harder
  • Mechanical brush cleaning of tubes is recommended if scale buildup is a problem

7. Maintain Condenser water flow rate

  • Eliminate scale buildup in the condenser tubes
  • Check valves for proper functioning
  • Check for clogged nozzles in the cooling tower, dirty water strainers, air in the water piping

8. Eliminate excess air

  • Review operating logs to determine refrigerant pressure
  • Air must be purged because it increases head, forcing the compressor to work harder
  • Check automatic purge unit for proper operation

9. Maintain Motor efficiency

  • Motor must be kept clean and cool
  • Motor improperly cooled if logs show increase in current draw without voltage increase
  • Megohmmeter all leads, terminal lugs, and wire connections
  • Bolts holding the motor in place should be tight
  • Lubricate bearings

10. Test Heat-Exchanger tubes

  • Outsource Eddy current testing and analysis

Office: 800-704-7685
101 E. Washington Bl, 10th Floor
Fort Wayne, IN 46802