Carrier PC211 Start-Up, Operation And Maintenance Instructions Manual page 169

Trimming Refrigerant Charge
The 19XL is shipped with the correct charge for the design duty of the machine. Trimming the
charge can be best accomplished when design load is available. To trim, check the temperature
difference between leaving chilled water temperature and cooler refrigerant temperature at full
load design conditions. If necessary, add or remove refrigerant to bring the temperature
difference to design conditions or minimum differential.
Click here for Table 9 — Refrigerant (HCFC-22 or HFC-134a) Charges
Preparation
Before starting the machine, check that the:
1. Power is on to the main starter, oil pump relay, tower fan starter, oil heater relay, and the
machine control center.
2. Cooling tower water is at proper level, and at or below design entering temperature.
3. Machine is charged with refrigerant and all refrigerant and oil valves are in their proper
operating position.
4. Oil is at the proper level in the reservoir sight glasses.
Initial Start-up