Carrier 50CD - Page 15

NO CHARGE — Use standard evacuating tech¬
niques. After evacuating system, weigh in the
specified amount of refrigerant. (Refer to Table 1.)
LOW CHARGE, COOLING — Using Cooling
Charging Chart, Fig. 28, vary refrigerant until the
conditions of the chart are met. Note the charging
chart is different from type normally used. Chart is
based on charging the units to the correct superheat
for the various operating conditions. Accurate pres¬
sure gage and temperature sensing device are re¬
quired. Connect the pressure gage to the service port
on the suction line. Mount the temperature
sensing device on the suction line and insulate it so
that outdoor ambient temperature does not affect
the reading. Indoor air cfm must be within the
normal operating range of the unit.
TO USE COOLING CHARGING CHART —
Take the outdoor ambient temperature and read the
suction pressure gage. Refer to chart to determine
what suction temperature should be. If suction tem¬
perature is high, add refrigerant. If suction tempera¬
ture is low, carefully blow some of the charge. Re¬
check the suction pressure as charge is adjusted.
Example: 50CD/CH008 (Fig. 28)
Outdoor Temperature.85 F
Suction Pressure. 70 psig
Suction Temperature should be.52 F
(Suction Temperature may vary ± 5 F.)
20 30 40 50
SUCTION LINE TEMPERATURE
60
( F)
70
80
-7 -i -4 10 16
SUCTION LINE TEMPERATURE (C )
21
27
Fig. 28 — 50CD/CH008 Cooling
Charging Chart
If Chargemaster® charging device is used, tem¬
perature and pressure readings must be accom¬
plished using the charging chart.
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