59
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 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 19 Packaged Units
without Receivers
Acceptable parameters range for water/glycol packaged units without receiver, with return air temperature of
65°F (18.3
C) to 85°F (29.4
C) and entering water/glycol temp of 65°F (18.3
C) to 85°F (29.4
C)
Refrigerant
Liquid Line
Pressure PSIG (kPa)
Liquid Line
Temp °F (°C)
Suction Pressure
PSIG (kPa)
Suction Sat.
Temp °F (°C)
Subcooling
Temp °F (°C)
Superheat
Temp °F (°C)
R-410A
290 to 390
(1999 to 2689)
85 to 100
(29.4 to 37.8
)
103 to 130
(710 to 896)
or greater
33 to 45
(0.56 to 7.2
)
8 to 15
(-13.3 to -9.4
)
12 to 18
(-11.1 to -7.8
)
R-407C
245 to 285
(1689 to 1965)
106 to 115
(41.1 to 46.1°)
53 to 70
(365 - 483)
or greater
33 to 45
(0.56 to 7.2
)
8 to 10°
(-13.3 to 12.2°)
8 to 15°
(-13.3 to -9.4°)
Table 20 Packaged Units
with Receivers
Acceptable parameters range for water/glycol packaged units with receivers, with return air temperature of 65°F
(18.3
C) to 85°F (29.4
C) and entering water/glycol temp of 65°F (18.3
C) to 85°F (29.4
C)
Refrigerant
Liquid Line
Pressure PSIG (kPa)
Liquid Line
Temp °F (°C)
Suction Pressure
PSIG (kPa)
Suction Sat.
Temp °F (°C)
Subcooling
Temp °F (°C)
Superheat
Temp °F (°C)
R-410A
290 to 390
(1999 to 2689)
85 to 100
(29.4 to 37.8
)
103 to 130
(710 to 896)
or greater
33 to 45
(0.56 to 7.2
)
0 to 3°
(-17.8 to -16.1
)
12 to 18
(-11.1 to -7.8
)
R-407C
245 to 285
(1689 to 1965)
106 to 115
(41.1 to 46.1°)
53 to 70
(365 - 483)
or greater
33 to 45
(0.56 to 7.2
)
0 to 3°
(-17.8 to -16.1
)
8 to 15°
(-13.3 to -9.4°)
Measure the superheat at the compressor suction line at least 6 inches (152 mm) away from the
compressor.
All water/glycol cooled units have a water regulating valve. A head pressure transducer is connected
to a Schrader fitting on the discharge line and water is regulated into the condenser coil (plate fin
condensers are standard).
WARNING:
If the system is charged from a vacuum, the preheating of the
compressor is not necessary. But if starting a compressor that has not
been charged from a vacuum, the crankcase heater must be energized
for a minimum of 12 hours to reduce the possibility of liquid slugging on
startup. Failure to energize the crankcase heater could result in
compressor damage.
Summary of Contents for DAMA-01
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