Bryant DURAPAC PLUS SERIES 542J, Installation, Start-Up And Service Instructions Manual

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VIII. REFRIGERANT CHARGE
Amount of refrigerant charge is listed on unit nameplate and
in Table 1.
Unit panels must be in place when unit is operating during
charging procedure.
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 appropriate cooling charging chart (see Fig. 38 and
39), add refrigerant until conditions of the chart are met.
Note that charging charts are different from those normally
used. Charts are based on charging units to correct super-
heat for various operating conditions. An accurate pressure
gage and temperature sensing device are required. Connect
temperature sensing device to service port on suction line
and insulate it so that outdoor ambient temperature does not
affect reading. Indoor-air cfm must be within normal operat-
ing range of unit.
C. To Use Cooling Charging Chart
Take outdoor ambient temperature and read the suction
pressure gage. Refer to appropriate chart to determine cor-
rect suction temperature. If suction temperature is high, add
refrigerant. If suction temperature is low, carefully recover
some of the charge. Recheck suction pressure as charge is
adjusted.
Example (Fig. 39)
Outdoor Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . 85 F
Suction Pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .70 psig
Suction Temperature Should be . . . . . . . . . . . . . . . . . . . . 60 F
(Suction Temperature may vary ± 5 F.)
D. Low Charge, Heating
If outdoor ambient temperature is above 40 F, operate unit
on cooling and refer to Low Charge, Cooling section above. If
outdoor ambient is below 40 F, evacuate system and weigh in
specified amount of refrigerant. (Refer to Table 1.)
IX. FILTER DRIER
Replace whenever refrigerant system is exposed to
atmosphere.
X. PROTECTIVE DEVICES
A. Compressor Protection
Overcurrent
Each compressor has one manual reset, calibrated trip, mag-
netic circuit breaker. Do not bypass connections or increase
the size of the circuit breaker to correct trouble. Determine
the cause of the trouble and correct it before resetting the
breaker.
Overtemperature
Each compressor has internal protector to protect it against
excessively high discharge gas temperature.
Crankcase Heater
Each compressor has 125-watt crankcase heaters to prevent
absorption of liquid refrigerant by oil in the crankcase when
the compressor is idle. Since power for the crankcase heaters
is drawn from the unit incoming power, main unit power
must be on for the heaters to be energized.
IMPORTANT: After a prolonged shutdown or service job,
energize the crankcase heaters for 24 hours before starting
the compressors.
Compressor Lockout
If any of the safeties (high-pressure or low-pressure, freeze
protection thermostat, compressor internal thermostat) trip,
or if there is loss of power to the compressors, the CLO (com-
pressor lockout) will lock the compressors off. To reset, man-
ually move the thermostat setting.
B. Indoor-Fan Motor Protection
A manual reset, calibrated trip, magnetic circuit breaker
protects against overcurrent. Do not bypass connections or
increase the size of the breaker to correct trouble. Determine
the cause and correct it before resetting the breaker.
C. Outdoor-Fan Motor Protection
Each outdoor-fan motor is internally protected against
overtemperature.
NOTE: A 3
1
/
2
-in. bolt and threaded plate are included in the installer’s
packet. They can be added to the motor support channel below the
motor mounting plate to aid in raising the motor.
Fig. 36 — 542J180 Indoor-Fan Motor Section
NOTE: Dimensions are in inches.
Fig. 37 — Outdoor Fan Adjustment