44
Cause
Corrective Action
calibration.
-
ADC IF1
: ADC value for factory calibrated Fail Point Inflow.
-
ADC IF2
: ADC value for factory calibrated Nominal Point Inflow.
-
ADC DFA
: ADC value for Actual Downflow – showing real time sensor reading.
-
ADC DF0
: ADC value for factory calibrated Zero Point Downflow (no downflow).
-
ADC DFN
: ADC value for Nominal Point downflow – based on field calibration.
-
CONSTANT
: value for Inflow sensor constant - keyed in during sensor calibration.
-
CALIB TEMP
: Temperature when the factory calibration was performed.
-
ADC TEMP
: ADC value for temperature.
Note: Depending on preset unit at SETTINGS>MEASUREMENT UNIT> (Metric or
Imperial), the units for temperature and velocity will change accordingly. For Metric-°C,
m/s while for Imperial-°F, fpm. Factory setting is at Metric.
1.
In order to prevent any AIRFAIL or unstable velocity displayed on LCD problem,
please ensure the following is done after the calibration:
a.
CONSTANT value is correct. Check it with constant written on airflow sensor body
or inside Replaceable Component Record List which comes with the test report.
b.
TEMPERATURE shows room temperature. If not, refer to next possible cause,part
B.
c.
ADC IF0 < ADC IF1 < ADC IF2. If not please re-do calibration in correct sequence:
SET CONSTANT → SET ZERO → CALIB. If CALIBRATION ERROR is encountered,
please refer to next possible cause, part A.
d.
ADC DF0 < ADC DFN. If not please re-do calibration in correct sequence: SET
CONSTANT → SET ZERO → CALIB. If CALIBRATION ERROR is encountered, please
refer to next possible cause, part A.
2.
Just after calibration, ADC IFA value should be close to ADC IFN value. If not, please
adjust the speed controller to make both values closer by at least ± 20 units.
Sensor Failure /
Sensor
Misalignment
A. Air Flow Sensor failure / misalignment
•
Airflow sensor the top of the cabinet (E/S series model) or inside the unit below the top
filter (D/G series model). Airflow sensor for D/G series models can be accessed from the
back of the unit. See Figure 5-1 below. It is a stainless steel tube with 2 round holes
facing up.
Important to check:
1.
Ensure that the sensor area is not blocked at all and that its through-holes are
perpendicular to the filter’s surface.
2.
Exhaust sensor is attached tightly to the box / housing.
3.
If sensor box is used, there is no gap between sensor box and filter surface. If doughnut
housing is used, the installation direction is in accordance with the airflow direction.
4.
Sensor box / housing is installed tightly to the cabinet.
•
Turn off the cabinet.
•
Open the front panel and locate electrical panel behind it.
•
Refer to the Component Layout at the beginning of this section to locate the main board
in the electrical box.
•
Using multimeter, check the exhaust sensor’s output voltage (DC) at channel AIN1(+)
and J1(-) on main board (See Figure 5-2 below).
•
The airflow sensor voltage should increase if airflow is increased and decrease if airflow
is decreased.
•
If your observations are different, check airflow sensor connection on top of the unit
(see Figure 5-5) and at connector D pin 9, 10, 11, 12 on electrical panel for any bad/loose
connection.
•
If connections are good but sensor is still not working properly, replace it.
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