Setting Unit Airflow; Blower Speeds; Speed Tap 3 - Default Lo Cooling; Speed Tap 4 - Optional Med Cooling - Bard 11EER WA W18AB-A User's Application Manual

Setting Unit Airflow

The unit is set from the factory at the default speed.
Most units have three selectable cooling speed taps
that can be utilized. The default speed is the lowest
cooling speed. The two higher speed taps can be used
for higher duct static applications so that the unit can
maintain the recommended airflow as shown in Table
14. The higher speeds can also be used when higher
sensible cooling is desired. To change to the higher
speed taps, move the orange/black wire on the blower
speed terminal block to either MED or HI. Refer to
Table 16 on page 36 for the corresponding airflow of
each tap. Set the unit duct static based on the highest
airflow that the unit will run at.
NOTE: Be sure to adjust the system static or blower
speed to maintain airflows above the minimum
recommendations to prevent freeze up conditions
if Balanced Climate mode is activated.
Do not operate the unit in Balanced Climate mode
if running high static applications as indicated in
the blower performance table. If Balanced Climate
mode is activated as described on page 17, the unit
will run in this mode at all times unless there is a
call for ventilation, electric heat or 2nd stage cooling
from a 2-stage thermostat. At that time, the unit will
automatically activate a higher speed tap.

Blower Speeds

Five factory programmed speed taps (torque settings)
are available for the motor, and are selected through
different unit modes of operation. These modes are
energized by 24VAC signals from the low voltage
terminal block located inside the control panel by a
thermostat or other controlling device. Each speed tap
is programmed by Bard at the factory to different motor
torque settings (see Figure 14).
Model
W18A
W18L
W24A
W24L
W30A
W30L
W36A
W36L
* Rated CFM and ESP on factory speed connection.
Manual 2100-689H
Page 32 of 42
TABLE 14
Recommended Airflow
Nominal Nominal
Rated CFM* Rated ESP*
600 .10
800 .10
950 .15
1150 .15
(Thermostat Control Circuit Wiring).
1. Start with unit wiring diagram to confirm proper
connections and voltage (see Figure 11).
FIGURE 14
Speed Taps
FIGURE 11
24VAC Common
24VAC Common
24VAC "R"
signal through
24VAC "R" Signal through
thermostat output.
thermostat output
Speed Tap 1: Vent Speed
Speed Tap 2: Balanced Climate Speed
24VAC Common
Speed Tap 3: Default Speed
Speed Tap 4: Medium Speed
Speed Tap 5: High Speed
24VAC "R" Signal through
thermostat output.
Multiple motor speed taps may be energized
simultaneously by 24VAC power during different modes
of operation. The highest number speed tap energized
takes priority with 5 being the highest and 1 being
the lowest. See Table 15 for the corresponding blower
speeds with the different modes of operation.
Programmed blower speed taps are as follows (see also
Figure 15):
Speed Tap 1: Vent/blower only speed
Speed Tap 2: Balanced Climate speed
Speed Tap 3: Default LO cooling & heating speed.
Energized by default for cooling operation through the
blower speed tap selection and is labeled as LO.
Speed Tap 4: Optional MED Cooling & heating speed.
Selected manually through the blower speed tap
selection and is labeled as MED.
Speed Tap 5: Optional HI cooling & heating speed.
Selected manually through the blower speed tap
selection and is labeled as HI.
Recommended Factory Speed
Airflow Range Connection
550 - 725
700 - 950
900 - 1125
1000 - 1200
refer to wiring diagram!)
a. If the low voltage communication is not present, check
the demand from the thermostat. Also check the
output terminal and wire(s) from the terminal strip or
control relay(s) to the motor.
b. If the motor has proper high voltage as identified
above (Motor not Running #1), and proper low voltage
to a programmed terminal, and is not operating, the
motor is failed, and will require replacement.
Manual 2100-467H
Page 23 of 23
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