Bryant 564B User Manual
Page 9
3. Insulate the temperature sensing device so that the outdoor
ambient doesn’t affect the reading.
4. Locate the measured suction line pressure in the top row of
Table 8 and the measured outdoor ambient temperature in
the left column of the table. Based on the two values,
determine the required suction line temperature.
5. If the measured suction line temperature is greater than the
tabulated temperature, add charge in the system.
048 and 060 units:
1. Measure discharge line pressure by attaching a gauge to the
service port.
2. Measure the liquid line temperature by attaching a tempera-
ture sensing device to it.
3. Insulate the temperature sensing device so that the outdoor
ambient doesn’t affect the reading.
4. Refer to the required subcooling in Tables 4 and 5 to find
the required subcooling based on the model size and the
outdoor ambient temperature.
5. Interpolate if the outdoor temperature lies in between the
table values. Extrapolate if the temperature lies beyond the
table range.
6. Find the pressure value corresponding to the measured
pressure on the compressor discharge line.
7. Read across from the pressure reading to obtain the Liquid
line temperature for a required subcooling.
8. Add charge if the measured temperature is higher than the
liquid line temperature value in the table.
9. Add charge using the service connection on the suction line
of the compressor.
IV.
INDOOR AIRFLOW AND AIRFLOW ADJUSTMENTS
NOTE: For cooling operation, the recommended airflow is 350 to
450 cfm per each 12,000 Btuh of rated cooling capacity.
Table 7 shows dry coil air delivery for horizontal discharge units.
Tables 9-11 show pressure drops.
NOTE: Be sure that all supply- and return-air grilles are open,
free from obstructions, and adjusted properly.
WARNING: ELECTRICAL SHOCK HAZARD
Failure to follow this warning could result in personal
injury or death.
Disconnect electrical power to the unit and install lockout
tag before changing blower speed.
Airflow can be changed by changing the 24 volts lead connections
of the blower motor.
Unit 564B blower motors are factory wired for rated airflow
operation.
A.
FOR 208/230-V BLOWER MOTORS
The motor lead speed connections are as follows:
SIZE
RATED AIRFLOW
HIGH AIRFLOW
024
Tap 1
Tap 3
030
Tap 2
Tap 4
036
Tap 1
Tap 3
042
Tap 2
Tap 4
SIZE
RATED AIRFLOW
HIGH AIRFLOW
Low
Stage
High
Stage
Low
Stage
High
Stage
048
Tap 1
Tap 3
Tap 2
Tap 4
060
Tap 1
Tap 3
Tap 2
Tap 4
V.
UNIT CONTROLS
All compressors have the following internal-protection controls.
A.
HIGH-PRESSURE RELIEF VALVE
This valve opens when the pressure differential between the low
and high side becomes excessive.
B.
LOSS OF CHARGE SWITCH
Located on the outdoor liquid line is a low-pressure switch which
functions as a loss-of-charge switch. This switch contains a
Schrader core depressor. This switch opens at 7 psig and closes at
22 psig. No adjustment is necessary.
Unit Control
Power
Thermostat
and subbase
G
Y
W2
W3
R
RED
GREEN
YELLOW
C
BROWN
WHITE
VIOLET
A05213
Fig. 10A—Control Connections (Sizes 024-042)
Unit Control
Power
Thermostat
and subbase
G
Y1
Y2
W2
R
RED
GREEN
YELLOW
W3
PINK
BROWN
C
WHITE
VIOLET
A05214
Fig.10B—Control Connections (Sizes 048-060)
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