Endress+Hauser Liquisys M CUM253 - Process Specific Errors

Diagnostics and troubleshooting Liquisys M CUM223/253
78 Endress+Hauser
7.3 Process specific errors
Use the following table to locate and correct errors.
Error Possible cause Tests and / or remedial measures Equipment, spare parts, personnel
Value indicated 0.0
Sensor / sensor cable defective Test with new or with different
functional sensor.
CUS31 or CUS41 (either type is suitable
for rough function test)
Sensor extension line interrupted Check junction boxes and line. Sensor simulation see chapter
"Maintenance of the entire measuring
point".
Incorrect sensor connection Check connection. See chapter "Wiring".
Instrument input defective Replace module MKT1 for testing. See spare parts list.
Data transfer errror Replace module LSGA (AC power supply
unit) or LSGD (DC power supply unit) for
testing.
See spare parts list.
Wiper blocked Switch instrument off and back on,
wiper has to wipe once.
Repair at manufacturer only.
Display value 0.0 Sensor completely blocked Clean optics Use spray cleaning or wiper.
Fixed incorrect measured
value
Impermissible instrument operating
state (no response to key actuation)
Switch instrument off and back on EMC problem: check line routing if
problem persists, check for possible
sources of interference.
Measured value
fluctuates
Measuring cable interference Connect cable screen acc. to connection
diagram (do not ground)
See chapter "Wiring".
Signal output line interference Check line routing
Try separate line routing, grounding
screen to PLC/PCS.
Separate signal output, meas. input and
supply lines.
Irregular flow rate / turbulence / air
bubbles / big solids particles
Choose better place of installation or
eliminate turbulences. Possibly use large
measured value damping factor.
Set gas bubble barrier to 100 %.
Measured value damping see field A5.
Display value implausible
/ no or creeping change of
display
No or incorrect sensor calibration Calibration with original sample
required for concentration or solids
concentration
See chapter "Calibration".
Sensor soiled Clean sensor. Remove coarse coats with brush.
Remove carbonates and similar coats
with 3 % hydrochloride acid.
Remove organic coats and grease with
oxidation agents and / or grease solvents.
Use spray cleaning. See instructions of assembly used for
spray cleaning.
Use wiper version. Wiper upgrade at factory.
Wiper rubber defective Replace wiper arm. Wiper arm service kit 50089252
Sensor installed in “dead” zone or air
cushion in assembly or flange
Check installation conditions, move
sensor to area with optimum flow
conditions. Caution if installed in
horizontal lines!
Incorrect sensor orientation Orient sensor:
• Measuring surface should face flow in
normal media.
• Orient meas. surface at 90° to flow in
media with high solids concentration
Frontal “bombardment” of measuring
surface with highly viscous solids may
result in an adhering coating.
Incorrect temperature
value
Temperature sensor defective If temperature display is required:
replace sensor.
Turbidity measurement itself does not
require temperature measurement.
Controller or timer cannot
be activated
No relay module installed Install LSR1-2 or LSR1-4 module. See spare parts list in chapter "Spare
parts".