AD-1252 Thermal Dispersion Probe Airflow Measuring System Installation Instructions
20
The LCD screen does not display
below certain values.
The ZERO CUTOFF value is set
incorrectly.
1. Record all settings for gain, square
feet, offset, 20 mA and 4 mA values.
2. Reset the electronic controller to
factory settings.
3. Ensure that the fan is off prior to
setting ZERO CUTOFF.
4. Reprogram other settings.
The LCD screen indicates ERROR!
CHECK CAT5 CABLE AND RESET.
The CAT5e connector cables are not
terminated properly or the combined
cable length is greater than 100 feet.
Check the CAT5e communications
cable termination.
Connect only one probe at a time and
cycle power between cable tests.
Use the shortest practical cable length.
The CAT5e cable must be a shielded,
plenum rated, straight-through patch
cable with simple pairing.
Do not
use crossover cables or
standard CAT5 pairing. See Table 5.
The LCD screen stops or freezes
during startup. LCD screen shows
-----------------------
The multiplex circuit is not
programmed.
Cycle power to the electronic controller.
Check the amber communication lights
on the bottom of the transmitter.
If more than one amber LED flashes at
the same time, the multiplexer circuit is
not properly programmed. If this
problem occurs, contact the factory.
The mA output has locked on a
single value.
The mA OUTPUT CALIBRATION
function did not exit properly.
4 mA and 20 mA are set to 0.
4 mA and 20 mA have less than a
500 FPM difference.
ESCAPE enters a zero value.
1. Press ESC and ENTER at the same
time to enter the OPTIONS MENU.
2. Press UP and DOWN at the same
time to enter the FACTORY MENU.
PROBE CALIBRATE appears.
3. Press UP or DOWN to scroll to the
desired mA CALIBRATION
submenu.
4. Press ENTER to access the desired
submenu.
5. Press ENTER to accept each value
and then press ESC.
The mA output appears to be moving
very slowly. The output is not
keeping up with the airflow.
The mA filter value is set too low. The
factory default is 0.35 mA.
Enter the OPTIONS MENU and
increase the mA filter value (to 0.25, as
an example). A value of 1.0 indicates
no filtering.
The mA output is constantly spiking
high, then low.
The mA filter value is set too high
(greater than 1.0).
Enter the OPTIONS MENU and
decrease the mA filter value (to
0.25 mA, as an example). The factory
default value is 0.35 mA.
Table 7: AD-1252 System Troubleshooting (Part 2 of 3)
Problem
Possible Cause
Corrective Action
