York Screw Chiller YCIV0197PA46

Refrigerant charge removed and all known leaks repaired?

System charged with a small amount of refrigerant mixed with dry nitrogen?

Used an electronic leak detector to detect any leaks that are too small to be found by the soap test?

Rated pressure of the unit refrigerant pressure relief valves not exceeded?

Conducting the gas pressure hold test

High-quality, high-resolution analog pressure gauge installed on one of the service valves?

All the system valves including manual valves and EEVs are 100% open?

All valves to the atmosphere are closed with flare caps in place, if applicable?

Connect a high-capacity vacuum pump with indicator to the charging valves as shown in Figure 147 on page 306 and Figure 148 on page 306

Ensure all the system valves including manual valves and EEVs are 100% open

Ensure that all valves to the atmosphere are closed with flare caps in place, if applicable

Operate the vacuum pump until a pressure of 5,000 μm is reached

To start the 8-hour vacuum hold test, close the system charging valve connection to the vacuum pump

Hold the vacuum obtained in Step 4 in the system for 8 hours

Check for pressure change with the chiller at the same temperature

Warning: This procedure requires trained personnel with PPE!

Enter the amount of chiller refrigerant charge

Reference the unit Sales Order screen on the chiller control panel to determine the required charge

Is the refrigerant charge level correct during operation?

Enter the evaporator approach (STD), discharge superheat and subcooling values

For new sales, these design values are included as part of the FOF

Enter the values for Evaporator approach, Discharge superheat, and Subcooling

Definitions: EST = Evaporator Saturation Temperature, LCHLT = Leaving evaporator liquid temperature, DT = Compressor Discharge Temperature, CST = Condenser Saturation Temperature

Warning: Ensure the vapor portion of the refrigerant container or cylinder has not been contaminated with other gases that are not R-134a, including air.

Is the appropriate saturation property for the correct refrigerant used?

Refer to Table 55 on page 314 for R-134a to determine if the saturation pressure and ambient temperature of the refrigerant in the container coincide.

Is only refrigerant vapor from the top of the drum or cylinder admitted to the system until system pressure is raised above the corresponding saturation pressure at the freezing point of the chilled liquids?

Enter the freeze point temperature and vapor charge to a pressure that is 5°F (2.78°C) higher than that freeze point.

Enter the starting weight for the refrigerant cylinder.

Is a refrigerant pump used to draw vapor from the chiller and discharge it to the vapor connection of the refrigerant cylinder?

Is air prevented from entering the system?

Is a suitable charging connection using new copper tubing or correctly selected flexible charging hoses created?

This procedure must be performed at the specified time by an industry certified technician who has been trained and qualified to work on this type of equipment

A record of this procedure being successfully carried out should be maintained on file by the equipment owner should proof of adequate maintenance be required at a later date for warranty purposes

Check superheat on the evaporator and the economizer feed to the compressor