Exchanging The Electronics Module - Siemens SITRANS LG250 Operating Instructions Manual

Fault description
5. Measured value
jumps sporadically to
100 % during filling
6. Measured value
jumps to ≥ 100 % or
0 m distance
Measurement error during emptying
Fault description
7. Measured value re-
mains unchanged in
the close range during
emptying
8. Measured value re-
mains reproducible
in one position during
emptying
Reaction after fault recti-
fication
PBD-51041056
Error pattern Cause
– Changing condensation or
contamination on the probe
0
time
– Level echo is no longer
detected in the close range
due to false signals in the close
range. The sensor goes into
overfill protection mode. The
0 time
max. level (0 m distance) as
well as the status message
"Overfill protection" are output-
ted.
Error pattern Cause
– False echo larger than the level
echo
– Level echo too small
0 time
– Stored false signals in this
position are larger than the
level echo
0
time
Depending on the reason for the fault and the measures taken, the
steps described in chapter "Setup" must be carried out again or must
be checked for plausibility and completeness.
9.5

Exchanging the electronics module

If the electronics module is defective, it can be replaced by the user.
In Ex applications, only instruments and electronics modules with ap-
propriate Ex approval may be used.
If there is no electronics module available on site, the electronics
module can be ordered through the agency serving you. The electron-
ics modules are adapted to the respective sensor and differ in signal
output or voltage supply.
The new electronics module must be loaded with the default settings
of the sensor. These are the options:
•
In the factory
•
Or on site by the user
In both cases, the serial number of the sensor is needed. The serial
numbers are stated on the type label of the instrument, on the inside
of the housing as well as on the delivery note.
SITRANS LG250 - Operating Instructions
Rectification
– Carry out a false signal sup-
pression
– Eliminate false signals in the
close range
– Check installation conditions
– If possible, switch off the func-
tion "Overfill protection"
Rectification
– Eliminate false signals in the
close range
– Remove contamination on the
probe. After having removed
the source of the false signals,
the false signal suppression
must be deleted.
– Carry out a new false signal
suppression
– Delete false signal memory
– Carry out a new false signal
suppression
59