Carrier WeatherMaster 50HC04, Service And Maintenance Instructions, Page: 15 / 132

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PURON ® (R-410A) REFRIGERANT
This unit is designed for use with Puron (R-410A) refrigerant.
Do not use any other refrigerant in this system.
Puron (R-410A) refrigerant is provided in pink (rose) colored
cylinders. These cylinders are available with and without dip
tubes; cylinders with dip tubes will have a label indicating this
feature. For a cylinder with a dip tube, place the cylinder in the
upright position (access valve at the top) when removing liquid
refrigerant for charging. For a cylinder without a dip tube, in-
vert the cylinder (access valve on the bottom) when removing
liquid refrigerant.
Because Puron (R-410A) refrigerant is a blend, it is strongly
recommended that refrigerant always be removed from the cyl-
inder as a liquid. Admit liquid refrigerant into the system in the
discharge line. If adding refrigerant into the suction line, use a
commercial metering/expansion device at the gage manifold;
remove liquid from the cylinder, pass it through the metering
device at the gage set and then pass it into the suction line as a
vapor. Do not remove Puron (R-410A) refrigerant from the
cylinder as a vapor.
Refrigerant Charge
Amount of refrigerant charge is listed on the unit’s nameplate.
Refer to Carrier GTAC2-5 Charging, Recovery, Recycling and
Reclamation training manual and the following procedures.
Unit panels must be in place when unit is operating during the
charging procedure.
NO CHARGE
Use standard evacuating techniques. After evacuating system,
weigh in the specified amount of refrigerant.
LOW-CHARGE COOLING
Using Cooling Charging Charts, Fig. 24-32, vary refrigerant
until the conditions of the appropriate chart are met. Note the
charging charts are different from type normally used. Charts
are based on charging the units to the correct sub-cooling for
the various operating conditions. Accurate pressure gage and
temperature sensing device are required. Connect the pressure
gage to the service port on the liquid line. Mount the tempera-
ture sensing device on the liquid line and insulate it so that out-
door ambient temperature does not affect the reading. Indoor-
air cfm must be within the normal operating range of the unit.
EXAMPLE:
Model 50HC*A04
Outdoor Temperature. . . . . . . . . . . . . . . . 85°F (29°C)
Suction Pressure. . . . . . . . . . . . . . . . . . . . 140 psig (965 kPa)
Suction Temperature should be . . . . . . . . 60°F (16°C)
USING COOLING CHARGING CHARTS
Take the outdoor ambient temperature and read the liquid pres-
sure gage. Refer to chart to determine what liquid temperature
should be. If liquid temperature is low, add refrigerant. If liquid
temperature is high, carefully recover some of the charge. Re-
check the liquid pressure as charge is adjusted.
COOLING CHARGING CHARTS
Fig. 24 — Cooling Charging Chart - 3 Ton
Fig. 25 — Cooling Charging Chart - 4 Ton
50HC SIZE DESIGNATION NOMINAL TONS REFERENCE
04 3
05 4
06 5
07 6
08 7.5
09 8.5
12 10
14 12.5
CHARGING CHART – R-410A REFRIGERANT
COOLING MODE – OUTDOOR FAN MUST BE RUNNING
160
140
120
100
80
60
40
20
150 200 250 300 350
400
450 500 550 600
Compressor Discharge Pressure (psig)
Outdoor Coil Leaving Refrigerant
T
e
mperature (Degrees F)
Add charge if above the curve
Remove charge if below the curve
48TM502520 REV C
Outdoor Coil Leaving Refrigerant
T
e
mperature (Degrees F)
CHARGING CHART – R-410A REFRIGERANT
COOLING MODE – OUTDOOR FAN MUST BE RUNNING
Remove charge if below the curve
Add charge if above the curve
160
140
120
100
80
60
40
20
150 200
250
300 350
400 450
500
550 600
Compressor Discharge Pressure (psig)
48TM502521 REV C