
53
Function
R-410A Conditions
Liquid Line Pressure
290 to 390 PSIG (2000 to 2687 kPa)
Liquid Line Temperature
85 to 100 PSIG (586 to 690 kPa)
Suction Pressure
103 to 130 PSIG (710 kPa to 896 kPa)
Suction Saturated Temperature
33 to 45°F (0.56 to 7.22°C)
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
Measure the superheat at the compressor suction line at least 6 inches (152 mm) away from the
compressor. Compare suction pressure and temperature reading between the dap4 and the
manifolds. If the difference between the manifold reading and dap4 reading is more than 5%,
check for the EEV wiring and any possible alarms on dap4, or EEV driver. Measure sub-cooling
at the liquid line.
When charging is complete, add the correct amount of oil, if the line run exceeds longer than 66
feet (20 m). This procedure must be conducted with the system running at high load (compressor
at full speed). See
APPENDIX: Additional Oil Required (Oz)
for proper amount of oil to add.
ALWAYS use clean original Danfoss POE oil 160SZ or equivalent from new cans.
After charging, verifying Sub-cooling and Oil Level, close the valve on the refrigerant manifold
gauge set and close the service valve on the refrigerant tank and disconnect the refrigerant
manifold gauge set.
5.7.1.3.
Variable Speed Compressor Pre-Charge
WARNING:
The fixed speed compressor (2
nd
stage) must be charged
before charging the variable speed compressor (1
st
stage) in a dual circuit
system.
NOTE:
Prior to refrigerant charging, a system vacuum and moisture
removal procedure must have been carried out. Refer to
Section
Triple Evacuation and Dehydration Procedure
system.
After the system has been properly evacuated. Calculate the proper charge by following the
steps.
1. Select the model and refrigerant charge for evaporator and condenser in accordance with
the following table.