4-20Ma, Hart Transmitters - K-TEK AccuTrak AT100 Installation & Operation Manual

6.5 4-20mA, HART Transmitters

Symptom Possible Problem
Display showing Threshold voltage too high
****
Unit in alarm
Electronics module failure
(20.97 or 3.61
Float missing or damaged
mA)
Sensor tube failure
Output unstable Threshold voltage too high
Threshold voltage too low
Rapid level changes
Short span (< 12" (600mm)) Increase the Damping
Excessive vibration
Steady output Residual magnetism on
with changing probe
level
Threshold voltage too low
Float not moving
LCD display not lit No power to the transmitter
Electronics module failure
Output does not DAC Trim
match display
Terminal Strip Failure
Cannot change Write protect jumper in the
menu settings ON position
Electronics module failure
Transmitter does The module is not equipped
not communicate with HART communications
via HART
The transmitter is in an
alarm condition
There is not enough loop
resistance for HART
communication
Electronics module failure
Incorrect Incorrect temperature
temperature calibration
indication
RTD failure
AT100-0200-1 Rev L (10-2010) DCN0528
Turn the threshold voltage adjustment counter-clockwise 1 full turn or follow
the threshold adjustment procedure in Section 6.8
Replace the existing module with a known working module
Inspect float for presence or damage, if damaged contact the factory for
replacement
Consult the factory for assistance
Turn the threshold voltage adjustment counter-clockwise 1 full turn or follow
the threshold adjustment procedure in Section 6.8
Turn the threshold voltage adjustment clockwise 1 full turn or follow the
threshold adjustment procedure in Section 6.8
Increase the Damping
Consult the factory for assistance
Swipe the sensor tube from the top to the bottom with a magnet
Turn the threshold voltage adjustment clockwise 1 full turn or follow the
threshold adjustment procedure in Section 6.8
Inspect the float for damage
Confirm the float is suitable for the process specific gravity
Inspect the sensor tube for buildup on probe
Check the field wiring for proper polarity and supply voltage at the transmitter
Replace the existing module with a known working module
Perform the DAC Trim procedure Section 4.8
Check the terminal strip per Section 6.7 and replace if necessary
Move the write protect jumper to the upper position and cycle the power
Replace the existing module with a known working module
Check the model number of the transmitter or module to confirm the module
type is M3 or higher
Determine and correct the cause of the alarm condition before preceding
further
Ensure at least 250 ohms of resistance exists in the loop wiring to best
facilitate HART communication
Replace the existing module with a known working module
Perform the TMP RSET and recalibrate the temperature sensor if necessary
Remove the electronics module. Check for resistance between the yellow and
red wires of the RTD. Consult the factory if the circuit is open.
Solution
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