Carrier 50TFQ008 Installation, Start-Up And Service Instructions Manual page 23

UNIT
VOLTAGE
400 V
Fig. 30 — Outdoor Fan Adjustment
Economizer Adjustment —
mizer section on page 11.
Refrigerant Charge —
listed on unit nameplate (also refer to Tables 1A and 1B). Refer
to Carrier Refrigerant Service Techniques Manual, Refriger-
ants section.
Unit panels must be in place when unit is operating during
charging procedure. Compressor must operate a minimum of
10 minutes before checking refrigerant charge.
NO CHARGE — Use standard evacuating techniques. After
evacuating system, weigh in the specified amount of refriger-
ant (refer to Tables 1A and 1B).
NOTE: Do not adjust refrigerant charge with the unit operating
in Heating mode. If charge is suspect, recover and weigh
refrigerant then compare with specification on the unit rating
plate.
LOW CHARGE COOLING — Use Cooling Charging
Charts, Fig. 31-33. Vary refrigerant until the conditions of the
appropriate chart are met. Note that charging charts are differ-
ent from the type normally used. Charts are based on charging
the units to the correct superheat for the various operating con-
ditions. Accurate pressure gage and temperature sensing device
are required. 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.
An accurate superheat, thermocouple- or thermistor-type
thermometer, and a gage manifold are required when using the
superheat charging method for evaluating the unit charge. Do
not use mercury or small dial-type thermometers because they
are not adequate for this type of measurement.
TO USE COOLING CHARGING CHARTS — Take the
outdoor ambient temperature and read the suction pressure
gage. Refer to appropriate chart to determine what the suction
temperature should be. If suction temperature is high, add
refrigerant. If suction temperature is low, carefully recover
some of the charge. Recheck the suction pressure as charge is
adjusted.
"A"
in. mm
3.50 89
Refer to Optional Econo-
Amount of refrigerant charge is
EXAMPLE: (Fig. 31)
Outdoor Temperature . . . . . . . . . . . . . . . . . . . . . . . .29 C (85 F)
Suction Pressure . . . . . . . . . . . . . . . . . . . . . . .483 kPa (70 psig)
Suction Temperature should be . . . . . . . . . . . . . . . . .8 C (46 F)
(Suction Temperature may vary ±3° C [±5° F].)
If charging device is used, temperature and pressure read-
ings must be accomplished using the charging chart.
LEGEND (Fig. 31-33)
Fig. 31 — Cooling Charging Chart, 50TFQ008
23
Outdoor-Air Temperature
Pressure
Compressor Suction Line
Temperature