Endress+Hauser Liquisys M COM 223 F, Operating Instructions Manual

Page: 55 / 82

Error Possible cause Remedy Equipment needed, spare parts
Displayed value too
small / Sensor
calibration may not be
possible
– Polarisation incomplete Wait for sensor to polarise after
commissioning (incl. interruptions
in operation) Polarisation is complete when
meas. value is stable; max. approx.
60 mins.
– Incorrect altitude setting Check altitude value
– Incorrect air pressure
measurement
Check pressure value in field S11.
Sea level: approx. 1013 mbar
500 m above M.: approx. 950 mbar Only with Plus packet.
Caution: display value = absolute
atmospheric pressure.
– Electrolyte soiled Replace electrolyte see Technical Information COS 21
– Air cushion under membrane Install new membrane cap For procedure and spare parts
ordering see Technical
Information COS 21
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
Incorrect temperature
value
– Incorrect sensor connection Verify connections using wiring
diagram Wiring diagram: s. Chap. 3.4 and 3.5
– Measuring cable defective Check cable Ohmmeter or field simulation
– Temp. sensor in sensor defective Measure sensor resistance
(blue and yellow sensor lines) Ohmmeter / s. Chap. for values.
8.8.1. With faults, replace sensor
Measured value
variations
– Faults on measuring cable Connect cable screening
according to wiring diagram see Chap. 3.4 and 3.5
– Faults on signal output line Check line routing,
possibly route line separately Lines signal output, Isolate
measuring input and power supply
– Irregular flow rate /
turbulence / big air bubbles
Choose better installation location
or eliminate turbulence.
Possibly use large measured value
loss factor
Measured value loss see field A4
Controller or time
cannot be activated – No relay module available Install module LSR1-2 or LSR1-4 see Chap. 8.4 and 8.5
Controller / limit contact
not working
– Controller switched-off Activate controller s. Chap. 5.5,or fields R2xx
– Controller in “Manual / Off” mode Choose “Auto” or “Manual / On”
mode
Keypad, REL key
– Pickup delay setting too long Disable or shorten pickup delay See fields R2xx
– “Hold” function active “Autom. hold” during calibration,
“hold” input activated;
“hold” via keypad active See fields S2 to S4
Controller / limit contact
works continuously
– Controller in “Manual / On” mode Set controller to “Manual / Off” or
“Auto” Keypad, REL and AUTO keys
– Dropout delay setting too long Shorten dropout delay See fields R2xx
– Control loop interrupted Check Measured value, current
output and relay contacts,
actuators, chemical supply
No O
2
current output
signal
– Line open or short-circuited Disconnect line and measure
directly on instrument mA meter 0–20 mA DC
– Output defective See Chap. 8.3
– Instrument with PROFIBUS PA/DP PA/DP instruments have no current
output
Fixed current output
signal
– Current simulation active Switch off simulation see Field O2
– Processor system out of sync Switch instrument off and back on EMC problem: check installation if
problem persists
Incorrect current output
signal
– Incorrect current assignment Check current assignment:
0–20 mA or 4–20 mA? Field O211
– Total load in current loop
excessive (> 500
Ω
)
Disconnect output and measure
directly on instrument
mA meter for 0–20 mA DC
Current output table not
accepted – Value interval too small Use sensible intervals
No temperature
output signal
– Instrument has only one current
output
Check variant using nameplate, if
necessary replace module LSCH-x1 Module LSCH-x2,
see Chap. 8.4.4 and 8.5.4
– Instrument with PROFIBUS PA/DP PROFIBUS instruments have no
current output Module LSR1-4
see Chap. 8.4.4 and 8.5.4
Chemoclean function
not available – No relay module (LSR1-x) or only
LSR1-2 installed
Install LSR1-4 module.
Chemoclean only enabled with
release code, which is supplied by
E+H with Chemoclean-upgrade.
Module LSR1-4,
see Chap. 8.4.4 and 8.5.4
– Additional function not enabled Check version using nameplate
OM253FE7.CHP
Liquisys M COM 223 F / 253 F Maintenance and troubleshooting
Hauser 53