Stulz CeilAir CW - Pressure;Temperature Settings; Refrigerant Characteristics

54 OCH0006F08/13/2024
CEILAIR
®
CW & DX IOM
2.9 REFRIGERANT CHARACTERISTICS
-30 °F Flooded Head Pressure Control
For units using flooded head pressure control, a receiver is used to store the refrigerant during the time the
condenser is not utilizing the extra refrigerant charge.
NOTE Allow 20% Refrigerant Expansion
It is important not to exceed 80% of the total condenser and receiver volume to allow room for expansion.
1. Fine tune the charge following steps #1 through #6 in section 2.8.7.3.
2. The head pressure control valve setting is printed on the side of the valve body; This setting is the lowest
head pressure maintained during system operation. It may be necessary to add refrigerant to raise the
head pressure to the setting printed on the valve, e.g., 225 psig (1.55 MPa) for R407C, or 290 psig (2.00
MPa) for R410A.
3. If a refrigerant level sight glass is included on the side of the receiver, it may be used to assist in charging
the air conditioning system. The proper charge can be confirmed by viewing the level of refrigerant in the
receiver(s) while the unit is running at an elevated discharge pressure.
4. Add additional refrigerant charge until the refrigerant level in the receiver rises to the center of the sight
glass, indicating the receiver is 80% filled.
5. When the refrigerant in the receiver reaches the center of the sight glass, the unit is fully charged.
CAUTION
Remove the blockage to the air intake of the condenser.
6. Fill out the applicable sections of Warranty Registration and Start-Up Checklist.
2.9 Refrigerant Characteristics
2.9.1 Pressure/Temperature Settings
Table 10 is provided to assist with the normal settings of the system for R407C and R410A refrigerant.
Where applicable, minimum and maximum settings are given along with normal operating pressures.
NOTE Different Refrigerant Pressures
The operating pressures for R410A refrigerant are significantly higher than R407C.