Carrier 50EQ - Manual (Page 11)

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Connect the pressure gage to the service port on
the suction line. Mount the temperature sensing de­
vice on the suction 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.
TO USE COOLING CHARGING CHART —
Take the outdoor ambient temperature and read the
suction pressure gage. Refer to chart to determine
what the suction temperature should be. If the
suction temperature is high, add refrigerant. If the
suction temperature is low, carefully blow some of
the charge. Recheck the suction pressure as charge
is adjusted. Example; 50EQ024, Fig. 13:
Outdoor Temperature........................................... 85 F
Suction Pressure............................................. 68 psig
Suction Temperature should be............................50 F
Suction Temperature may vary..........................±2F
If Chargemaster® charging device is used, tem­
perature and pressure readings must be accom­
plished using charging chart, Fig. 13.
LOW CHARGE HEATING — If the outdoor
ambient temperature is above 45 F, operate unit on
cooling and refer to LOW CHARGE, COOLING.
If outdoor ambient is below 45 F, evacuate system
and weigh in specified amount of refrigerant. (Refer
to Table 1.)
Fig. 12 — Economizer Damper Details
POWER FAILURE — Dampers do not have a
spring return. In the event of a loss of power,
dampers remain in position until power is restored.
Do not manually operate damper motor. Damage to
motor will result.
Refrigerant Charge — Amount of unit refrigerant
charge is listed on unit nameplate (or refer to Table
1). Refer to Carrier Standard Service Techniques
Manual, Chapter 1, Refrigerants.
Unit panels must be in place when unit is
operating during charging procedure.
NO CHARGE — Use standard evacuating tech­
niques. After evacuating system, weigh in the speci­
fied amount of refrigerant.
LOW CHARGE — Using charging chart (Fig. 13,
14, or 15) add refrigerant until the conditions of the
chart are met. Note that the charging chart is differ­
ent from the one normally used. Chart is based on
charging the units to the correct superheat for the
various operating conditions. An accurate pressure
gage and temperature sensing device are required. Fig. 13 — Charging Chart — Cooling.
50EQ024
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