Refrigerant Charge; Replacement Parts - Bryant 558D Installation, Start-Up And Service Instructions Manual

IV. REFRIGERANT CHARGE
Amount of refrigerant charge is listed on unit nameplate (also
refer to Table 1). Unit panels must be in place when unit is
operating during charging procedure.
This unit uses a fixed-orifice refrigerant metering device lo-
cated in the coil header. There is one orifice in each coil cir-
cuit. The size of the orifice is stamped on the outside of the
tube where the orifice is located. Orifices are factory-selected
for optimum performance and are not designed to be changed
in the field. To determine if an orifice is plugged, disconnect
power to the evaporator-fan motor and start the unit in Cool-
ing mode. Observe the coil for an uneven frost pattern, indi-
cating a plugged orifice.
A. No Charge
Use standard evacuating techniques. After evacuating sys-
tem, weigh in the specified amount of refrigerant. (Refer to
Table 1.)
B. Low Charge Cooling
Using Cooling Charging Charts, Fig. 40-43, 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 super-
heat for the various operating conditions. 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 insu-
late it so that outdoor ambient temperature does not affect
the reading. Indoor-air cfm must be within the normal oper-
ating range of the unit.
C. To Use Cooling Charging Charts
Take the outdoor ambient temperature and read the suction
pressure gage. Refer to appropriate chart to determine what
suction temperature should be. If suction temperature is high,
add refrigerant. If suction temperature is low, carefully re-
cover some of the charge. Recheck the suction pressure as
charge is adjusted.
Example: (Fig. 42)
Outdoor Temperature . . . . . . . . . . . . . . . . . . . . . . . 85 F
Suction Pressure . . . . . . . . . . . . . . . . . . . . . . . . 80 psig
Suction Temperature should be . . . . . . . . . . . . . . . . 68 F
(Suction Temperature may vary ± 5 F.)
D. Refrigerant Leaks
Proceed as follows to repair a refrigerant leak and to charge
the unit:
1. Locate leak and ensure that refrigerant system pres-
sure has been relieved.
2. Repair leak following accepted practices.
NOTE: Install a filter drier whenever the system has been
opened for repair.
3. Add a small charge of R-22 refrigerant vapor to system
and leak-test unit.
4. Evacuate refrigerant system if additional leaks are not
found.
5. Charge unit with R-22 refrigerant, using a volumetric-
charging cylinder or accurate scale. Refer to unit rating
plate for required charge. Be sure to add extra refriger-
ant to compensate for internal volume of filter drier.
V. REPLACEMENT PARTS
A complete list of replacement parts may be obtained from
your distributor upon request.
Fig. 39 — Condenser-Fan Adjustment
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