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Method Of Statement For Precommissioning & Commissioning of Chillers

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This procedure or method statement covers the precommissioning & commissioning of individual chiller units only.

The complete sequence of operation including the precommissioning & commissioning of Chiller Plant Manager is covered separately.

Precommissioning Procedure for Chillers

Ensure that the chiller installation is complete and mechanical completion is approved. Ensure that no damage occurs between mechanical completion & precommissioning. Repair all damages to the equipment finish paint.

Check chillers are installed as per the approved shop drawings, method statement and manufacturer’s instructions. Check all chilled water piping & condensate drain in the chiller yard & other areas is correctly supported, with proper valve package, drain, air vents, instruments, etc as per the approved shop drawings & fully insulated.

Check the chilled water pumps for proper connections. Ensure flushing, chemical cleaning & addition of permanent chemicals is complete in line with the approved method statement.

Check for proper electrical power, control and earthing connections as per manufacturer’s recommendations. Field wiring / cabling is to be pretested for continuity and insulation resistance. Check all BMS requirements are completed.

  1. Check for proper unit voltage phasing
  2. Ensure the chilled water pumps are interlocked with respective chillers.
  3. Ensure all the refrigerant valves in the discharge, liquid, oil & oil return lines are open.
  4. Check condenser fans for free rotation.
  5. Check and record model & sr. number of chiller & compressors.
  6. Check and record kW rating of motor.
  7. Check and record motor RPM.
  8. Verify that all the refrigerant valve are open.
  9. Check the power voltage to the unit.
  10. Energize the compressor sump heaters & oil seperators 24 Hrs prior to start.
  11. Ensure controls and safety interlocks are installed and connected.
  12. Ensure that chilled water pump is working and water is being circulated.

Commissioning Procedure for Chillers

  1. Ensure that all the chiller precommissioning checks are satisfactory.
  2. Check refrigerant charge is sufficient. A shortage of refrigerant is indicated if operating pressures are low & subcooling is also low. If the operating pressures, sight glass, superheat and subcooling
    readings indicate a refrigerant shortage, charge refrigerant into each circuit. With the unit running, add refrigerant vapour by connecting the charging line to the suction service valve until operating
    conditions become normal.
  3. Check & record the refrigerant pressures in the suction & discharge.
  4. Move the chiller Switch on Microprocessor Control Panel on Chiller Panel to STOP-RESET position.
  5. Adjust the set point values in the UCM menus as described in the Operation Manual.
  6. After ensuring for proper interlocks, start the chiller.
  7. Allow the chiller to run for approximately 60 minutes to stabilize the operation of chillers.
  8. Check & record evaporator water entering temperature.
  9. Check & record evaporator water leaving temperature.
  10. Check water flow across evaporator.
  11. Check & record evaporator refrigerant temperature.
  12. Check & record condenser refrigerant temperature.
  13. Check system superheat (default is 3.5oC)
  14. Check system subcooling.
  15. Ensure the following status displays:
  16. a) Entering chilled water temperature.
    b) Leaving chilled water temperature
    c) Evaporator cutout (default is 3.8oC)
    d) Condenser pressure (default is HP-28.5 bar)
    e) Control set points
    f) Operating hours
  17.  Check & record ambient temperature.
  18. Check & record electrical parameters such as voltage and current of each compressor.
  19. Check operation of motorized valve in outlet of chiller.
  20. Check loading /unloading of chiller by varying the load on chiller & observing the switching ON/OFF of the compressors, condenser fans, etc.

Chiller Operational Control Test

  1. Check for automatic compressor lead/lag.
  2. Check for pump out at the beginning & end of every cycle.
  3. Check for capacity control.
  4. Checkf for seven day time schedule.
  5. Check for demand limit control Safety Control Test.
  6. Ensure that all safety control test is carried out by electric signals at the compressor motor.
  7. Check for loss of refrigerant charge protection.
  8. Check for low water flow protection.
  9. Check for low chilled water temperature protection.
  10. Check for low & high superheat protection.
  11. Check for low control voltage protection.
  12. Check for visual alarm signal.
  13. Check for low oil protection in the compressors Indicators Test.
  14. Check for proper fucntioning of all indicator lights

ATTACHMENTS

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