1. Purpose & Scope
Standard operating procedure for the safe sequential start-up, operational monitoring, and shutdown of water-cooled centrifugal chiller plants conforming to ASHRAE Guideline 22.
2. Personal Protective Equipment (PPE) & Hazards
- Safety Shoes & Eye Protection (Face Shield)
- Hearing Protection (Ear Muffs)
- High pressure refrigerant R-134a / R-1234ze hazard
- 415V / 3.3kV High voltage starter panels
3. Sequential Execution Steps
- Energize Cooling Tower & Condenser Water Circuit: Start the cooling tower fan on VFD low speed (20 Hz). Start designated condenser water pump (CWP). Verify condenser water flow switch proves on BMS within 15 seconds.
- Energize Primary / Secondary Chilled Water Pumps: Start primary chilled water pump (PCHWP). Open motorized isolation valve on active chiller evaporator barrel. Confirm differential pressure across evaporator barrel is between 0.3 – 0.6 bar (4.5 – 9 PSI).
- Initiate Chiller Microprocessor Start Command: Switch chiller control panel from LOCAL OFF to AUTO / REMOTE START. The unit will initiate lubrication pre-lube cycle for 60 seconds (Oil pressure >= 25 PSI above suction).
- Monitor Compressor Acceleration & Soft-Start: Observe motor starter ramp up (Star-Delta or VFD). Verify running current stabilizes below Full Load Amps (FLA). Confirm guide vanes modulate slowly from minimum position.
- Verify Steady-State Operating Parameters: After 15 minutes of operation, log parameters: Chilled Water Leaving (44°F / 6.7°C), Condenser Entering (85°F / 29.4°C), Approach Temperature (< 2.0°F), Oil Temp (130-145°F), Motor Amps.
- Chiller Normal Shutdown Sequence: Select NORMAL STOP on panel. Microprocessor unloads guide vanes to 0%, opens recycle bypass, trips main compressor motor, runs post-lube oil pump for 180 seconds, and shuts down chilled/condenser water pumps after 5 minutes.
