Bryant 502A User Manual

Page 8

Printed in U.S.A.

CATALOG NO. 04-53502001-01

XIII. 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. Unit must operate for at least 10 min-
utes before adjusting charge.

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. 5-7, 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 insulate it so that surrounding ambient temperature
does not affect the reading. Indoor-air cfm must be within
the normal operating range of the unit.

B. To Use Cooling Chart

Take the 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 recover
some of the charge. Recheck the suction pressure as charge
is adjusted.

Example: (Fig. 5)

Ambient Temperature . . . . . . . . . . . . . . . . . . . . . . . . .85 F

Suction Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . 70 psig

Suction Temperature should be . . . . . . . . . . . . . . . . .47 F

(Suction Temperature may vary ± 5 F.)

Fig. 5 — Charging Chart — 502A036

Fig. 6 — Charging Chart —502A048

Fig. 7 — Charging Chart — 502A060