Setting Unit Airflow; Figure 23 Increasing Heating Speed - Bard W24G4 Installation Instructions Manual

34. SETTING UNIT AIRFLOW

All models have multiple speed direct drive blower
motors. If supply and return ducts are connected to
the unit, the ducts must be of adequate size. Refer
to the appropriate blower tables. See Tables 12, 13,
14, 15, 16 and 17 for maximum static pressures
acceptable. Note the minimum CFM for Heating and
Cooling operation.
The unit is set from the factory at the default speed.
W**G units have three (3) selectable speeds for cooling
and two (2) selectable speeds for heating. First set
the airflow for heating. For high static applications
the speed should be set to high. When in doubt,
note the allowable air temperature rise listed on the
name plate and using the procedure listed in Section
23, "Measuring Air Temperature Rise", measure the
air temperature rise. If the temperature rise is above
allowable range, the heating airflow must be increased.
To increase the heating airflow speed:
• First disconnect power to the unit.
• Open the control panel and find the furnace control
board (see Figure 23).
• Remove the black wire from the unused terminal
and then remove the red wire from the heat
terminal.
• Install the red wire on the unused terminal and the
black wire on the heat terminal.
• Close the control panel and repeat the air
temperature rise test.
• To reduce the heating airflow speed from high
to standard, move the black wire from the heat
terminal to the unused terminal and the red wire
from the unused terminal to the heat terminal.
The default speed for cooling is the rated cooling speed
that is listed in Tables 12, 13, 14, 15, 16 and 17.
The higher cooling speed tap can be used for higher
duct static applications or to increase the sensible
cooling capacity. The higher speeds can also be used
when higher sensible cooling is desired.
To increase the cooling airflow speed:
• First disconnect power to the unit.
• Open the control panel and find the terminal block
above the blower relay (see Figure 24 on page 44).
FIGURE 23
Increasing Heating Speed
FURNACE CONTROL BOARD
BLACK
RED
STANDARD HEATING AIRFLOW
BLACK
RED
STANDARD TO HIGH
BLACK
RED
HIGH HEATING AIRFLOW
RED
BLACK
MIS-4138
Manual 2100-721B
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MIS-4138
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