Stulz CeilAir CW - DX Unit Charging Requirements; R407 C;R410 A Refrigerant; Remote Air-Cooled Systems (AR;AHU)

48 OCH0006F08/13/2024
CEILAIR
®
CW & DX IOM
2.8.2 DX UNIT CHARGING REQUIREMENTS
2.8.2 DX Unit Charging Requirements
When performing the specific DX charging procedures in this section, follow these best practices:
• Ensure that contamination of different refrigerants does not occur when using charging equipment.
Hoses or lines must be as short as possible to minimize the amount of refrigerant contained in them.
• Keep cylinders upright.
• Ensure the refrigeration system is grounded to Earth before charging the system with refrigerant.
• Label the system when charging is complete (if it is not labeled already).
• Exercise extreme care to avoid overfilling the refrigeration system.
Before recharging the system, it must be pressure tested with oxygen-free nitrogen (OFN). The system must
be leak tested upon completion of charging but prior to commissioning. A follow-up leak test must be carried
out prior to leaving the site.
2.8.3 Remote Air-Cooled Systems (AR/AHU)
Remote air-cooled units are provided with a dry nitrogen holding charge which must be removed before
piping and charging the unit.
CAUTION
POE oil is used in systems with R407C or R410A refrigerant. POE oil quickly absorbs moisture when
exposed to air. High POE oil moisture levels react with refrigerant to form acid which results in system
contamination. Keep the entire system sealed as much as possible and minimize exposure of the POE oil
to outside air.
NOTE Mechanic or Technician Required
Refrigerant charging must be performed by a qualified air conditioning technician.
2.8.4 R407C/R410A Refrigerant
CeilAir systems use either R407C or R410A refrigerant. Refrigerant charging pressures vary depending
on the type of refrigerant used in the unit. Before charging, check the unit nameplate to confirm the type of
refrigerant to use. Tables are provided in section 2.9 showing the temperature/pressure characteristics for
R407C and R410A.
CAUTION
R407C and R410A can contribute to the greenhouse effect if released. Avoid releasing the refrigerant
into the atmosphere.
WARNING
R407C or R410A refrigerant released in an enclosed space can suffocate those nearby.
R407C and R410A are multi-component blends whose component parts have different volatilities that
result in a change in composition and saturation temperature as evaporation and condensation occur.
Typically, the composition of R407C vapor is different than that of R407C liquid within a contained system.
The composition of liquid R407C refrigerant remains relatively constant, however, the refrigerant vapor tends
to separate into its component parts even when circulating.