
58
Function
R-410A Conditions
Discharge Pressure
322 PSIG (2220 kPa) minimum
Suction Pressure
104 PSIG (717 kPa) or greater
Subcooling
8 to 15°F (-13.33 to -9.44°C)
Differential Temperature - Depending on ambient
conditions
Superheat
8 to 18°F (-13.33 to -7.78°C)
Differential Temperature
5.7.2.2.
Variable Capacity Compressor
•
See
Charge Variable Speed Compressor
for charging the variable speed compressor
except use the table below for the proper charge conditions.
•
The unit should be allowed to stabilize for 15 to 20 minutes to verify key measurements in
the table below.
Function
R-410A Conditions
Discharge Pressure
322 PSIG (2220 kPa) minimum
Suction Pressure
104 PSIG (717 kPa) or greater
Subcooling
8 to 15°F (-13.33 to -9.44°C)
Differential Temperature - Depending on ambient
conditions
, at compressor’s maximum speed
Superheat
8 to 18°F (-13.33 to -7.78°C)
Differential Temperature
5.7.3. Water/Glycol-Cooled System Charging
All water/glycol cooled units are factory charged with refrigerant. The water regulating valve
should be adjusted to maintain the required conditions. Field charging, if required, of water/glycol
systems should be done by referring to the unit’s electrical nameplate. The factory charge is
indicated on the nameplate. Although this figure represents the initial factory charge, it is still
necessary to measure and note proper unit operation including superheat, head and suction
pressure. Some adjustment of charge may be required.
Adjust the refrigerant charge until the sight glass clears or has sparse bubbles. The system
should be allowed to stabilize for 15 to 20 minutes before meaningful measurements can be
taken. After the system stabilize, verification of a few key measurements should be noted.
Table 1 - Packaged Units without Receivers
Acceptable parameters range for water/glycol packaged units without receiver, with return air temperature of
65°F to 85°F and entering water/glycol temp of 65 - 85°F (110°F for Glycol)
Refrigerant
Liquid Line
Pressure (psig)
Liquid Line
Temp (°F)
Suction
Pressure (psig)
Suction
Sat.
Temp (°F)
Subcooling
Temp (°F)
Superheat
Temp (°F)
R410A
290
– 390
85 - 100
103 - 130
33 - 45
8- 15
12 - 18