Table 16 Refrigerant Charge Values - Data Aire DAPA-2.5 Installation, Operation & Maintenance Manual

Use the Temp Setpoint under Menu B – Setpoints to force the circuit 1 compressor to start in the normal
operating mode. A call for cooling can artificially be created from the controller by setting the Temp
Setpoint to a value lower than the current ambient temperature in the space.
Example: Existing return air temperature (RAT) is 75F (23.9C), set the controller Temperature
Setpoint to 65F (18.3C). The compressor will start and run at a full speed.
If the unit is in OFFbyKEY position, hold the ESC key for 5 seconds to start the system via the controller.
Allow time for all fans to start and for the system to stabilize to room temperature. Bubbles in the sight
glass are not unusual at this point. It is likely that more refrigerant will be required to complete the
charging procedure.
Finish charging circuit 1 by slowly opening the valve on the refrigerant manifold set to meter liquid
refrigerant into the low side of the system. Use a liquid charging adapter to prevent liquid refrigerant
from entering the compressor.
Adjust the refrigerant charge to the subcooling value shown in the table below and the sight glass has
sparse bubbles. The unit should be allowed to stabilize for 15 to 20 minutes to verify key measurements
in

Table 16 Refrigerant Charge Values

Function
Discharge Pressure
Liquid Line Pressure
Liquid Line
Temperature
Suction Pressure
Suction Saturated
Temperature
Subcooling
Superheat
Measure the superheat at the compressor suction line at least 6 inches (152 mm) away from the
compressor. Measure subcooling at the liquid line.
NOTICE: Charging to a full liquid line sight glass should never be the sole
means of determining the correct refrigerant charge. Other parameters such
as superheat, suction pressure, head pressure, subcooling and ambient
temperature are also important factors. A system charged to a clear sight
glass is often overcharged.
below.
Table 16 Refrigerant Charge Values
R-410A Conditions
322 PSIG (2220 kPa)
minimum
290 to 390 PSIG
(2000 to 2688 kPa)
85 to 100°F
(29.4 to 37.8°C)
103 to 130 PSIG
(710 to 896 kPa)
33 to 45°F
(0.56 to 7.2°C)
8 to 15°F
(-13.3 to -9.4°C)
Differential Temperature - Depending on ambient conditions, at
8 to 18°F
(-13.3 to -7.8°C)
R-407C Conditions
199 PSIG (1372 kPa)
245 to 285 PSIG
(1689 to 1965 kPa)
(41.1 to 46.1°C)
53 to 70 PSIG
(365 to 483 kPa)
(0.56 to 7.2°C)
(-13.3 to -12.2°C)
compressor's maximum speed
(-13.3 to -9.4°C)
Differential Temperature
53
minimum
106 to 115°F
33 to 45°F
8 to 10°F
8 to 15°F