Basic Troubleshooting - Emerson Magtech LTM−350 Series Instruction And Operation Manual

August 2020
2. Water damage
Water damage to the electronics module or sensor probe.
This is potentially the most severe case the symptoms are
unpredictable. If there is any suspicion that the transmitter
may have incurred water damage please contact the factory
to make arrangements to have the unit sent back for factory
inspection.
Physical and water damage are not covered under
warranty
3. Magnetic Indentation
It is possible for any magnetostrictive instrument to have
residual magnetic energy stored along the length of the
waveguide. These magnetic anomalies can interfere with
the output response signal. If this appears to be the case a
level gage float (or a bar magnet preferably) may be run
along the length of the sensor tube, past the head of the
transmitter, in an even motion without stopping. This will
usually clear all such magnetic anomalies.
Never move a magnet in perpendicular motion away
from the sensor tube. This will always leave a residual
magnetic field in the waveguide which causes the transmitter
output to be erroneous or unstable.
The LTM-350 is HART compatible, however HART
communication will not work if the unit is not powering up.

6.2 Basic Troubleshooting

Symptom
Polarity Check
Transmitter is not
powering up. The
LCD is not turning
on and there is
zero mA current
Electronics not
draw.
making proper
connection to power
connector.
Configuration
settings not
optimized
Output of
transmitter is
erratic
OR in constant Electronics module
failure mode failure
Sensor probe failure
18
Reference Manual
L231040 Rev AD
Potential Possible
Issue/Problem Solution
The transmitter is
polarity protected.
Check the field
wiring to make sure
the plus and minus
connections are not
reversed.
Make sure the
electronics module
is seated properly.
Open the front
cover (where the
LCD is) and firmly
push on the
"Magtech" text. A
good way to tell if
the electronics are
not seated properly
is by making sure
the protection
screws are not
physically higher
than the outside of
the housing.
Sometimes pulling
the electronics
module out and
putting it back in
can reseat the
electronics
correctly. Use
cutters or needle
nose pliers to grip
the protection
screw and lightly
pull on each screw
(alternate).
Change signal
parameters. See
section " " or
contact factory for
assistance.
Replace electronics
with known
working electronics
from a sensor of
similar length
and/or contact
factory for
replacement
assistance.
Consult factory for
assistance.