Dust Sensor; Dust Sensor Failure Alarm; High Dust Limit Alarm; Figure 48 Dust Sensor - Bard FUSION-TEC WR36BPA Service Instructions Manual

8. Press ENTER key to save the value and move
cursor to Damper Override.
9. Press UP or DOWN keys to change the value from
OFF to ON.
10. The Damper Position will update with the new
override value and the damper will travel to that
position.
The override will last for 5 minutes or until the Damper
Override parameter is set to OFF again.
NOTE: If unit is operating at the time the damper
override is being enabled, adjustments must be
made to OV Speed first before switching Damper
Override on.

Dust Sensor

The unit has a dust sensor installed near the outdoor air
inlet. The dust sensor checks for excessive particulates
in the outdoor air, and will close the economizer if
the dust is excessive. The sensor uses a PWM signal
converted to 0-5v output to the controller.
To ensure proper performance, cleaning may be
required. Vacuuming or blowing the dust off the sensor
with forced air is recommended. Avoid inserting any
objects into the sensor.
The dust sensor can be verified by:
1. Press MENU key to go to the Main Menu screen.
2. Press UP or DOWN keys and ENTER key to enter
TECHNICIAN password 1313.
3. Press UP or DOWN keys to scroll to I/O Config;
press ENTER key.
4. Press UP or DOWN keys to scroll to Dust Sensor
C7.
5. Reference the Value for the current sensor reading
(see Figure 48).
FIGURE 48
Dust Sensor
6. To apply an offset to the current reading, press
ENTER key to scroll to Offset.
7. Press UP or DOWN keys to adjust the value to the
desired value.
8. Press ENTER key to save the value and move
cursor back to top of screen.
Manual 2100-695
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NOTE: The sensor can be disabled if required for
troubleshooting.
9. Press ENTER key to scroll to Enable parameter.
10. Press UP or DOWN keys to change the value from
ON to OFF.
11. Press ENTER key to save.

Dust Sensor Failure Alarm

When the sensor reads a value that is outside of
the acceptable 0 to 100% range, an alarm will be
generated indicating the sensor has failed. This alarm
is just a notification and will not disable any other
features on the controller.
This alarm is fixed and cannot be adjusted.

High Dust Limit Alarm

When dust content in the air is high and is a risk
to prematurely reducing airflow through the filters,
the unit will restrict the use of the economizer. The
controller has adjustable software setpoints (default to
80%) to indicate dust levels are too high and to disable
the economizer operation for 5 minutes (unit default).
This alarm is not communicated to the NOC. Once
the conditions are no longer present, the alarm will
automatically clear.
Disabling the dust sensor in I/O Config disables this
alarm.
To adjust the dust sensor alarm setpoint:
1. Press MENU key to go to the Main Menu screen.
2. Press UP or DOWN keys and ENTER key to enter
USER password 2000.
3. Press UP or DOWN keys to scroll to System Config;
press ENTER key.
4. Press UP or DOWN keys to scroll to Alarm Setup
A9.
5. Press ENTER key to scroll to Setpoint (see Figure
49).
6. Press UP or DOWN keys to change to the desired
value.
7. Press ENTER key to save the value.
FIGURE 49
Adjusting Dust Sensor Alarm Setpoint