8 Troubleshooting
Mycom S CPM 153
100
Hauser
pH value in process
incorrect
No / incorrect temperature compen-
sation
ATC: Activate function
MTC: Set process temperature
Conductivity of medium too low
Select pH electrode with salt supply
or liquid KCl
e. g. Orbisint CPS 11-xASxx
or Ceraliquid CPS 41
Flow rate too high
Reduce flow rate or measure in a
bypass
Potential in medium
poss. earth with / at PM pin (connect
PM to PE)
Problem mainly occurs in plastic lines
Device unsymmetrical and PAL
connected
possibly earth with / at PA pin (connect
PA to PE)
Electrode covered in dirt or deposits Clean electrode (see Chap. 8.8.1)
highly polluted media:
Use spray cleaning
Measured values
fluctuate
Interference in measuring cable
Connect cable screens as per terminal
diagram
Wiring diagram see Chap. 4.1.1
Interference in signal
output line
Check line installation, possibly route
line separately
Interference potential in medium
Symmetrical measurement (with PML)
No potential matching (PA/PM)
With symmetrical measurement
Connect PM pin in assembly to instru-
ment terminal PA/PM
poss. ground medium by connecting
PM to PE
Div. controller, timer or
clean functions cannot
be activated
Relay module not available for relay
3 - 5
Install 3 relay module M3R-3
For order number and installation see
Chap. 8.4
Controller / limit contact
does not work
Controller switched off
Activate controller see Chap. 6.5
Controller in “Manual / Off” mode
Select "Auto" or "Manual on" mode
Keypad / PARAM / manual operation /
contacts
Pick-up delay setting too long
Switch off or shorten pick-up delay
period
"Hold" function active
"Auto hold" during calibration
"Hold" input activated
Manual "hold" active using keypad
"Hold" active during configuration
Determine cause of hold and eliminate
if not desired
"Hold" is indicated in display when
active
Controller / limit contact
work continuously
Contact in "Manual/on" mode
Set controller to "Manual/off" or "Auto"
Dropout delay setting too long
Shorted dropout delay period
Control circuit interrupted
Check measured variable, current out-
put or relay contacts, actuators, chemi-
cal supply
No pH/mV current
output signal
Line open or short-circuited
Disconnect both (!) lines and measure
directly on instrument
mA meter 0–20 mA DC
Output defective see Chap. 8.2.4
Replace controller module
Fixed current
output signal
Current simulation active
Switch off simulation
see DIAG / Service / Simulation
Processor system out of sync
Switch instrument off and on
EMC problem: If repeated, check
installation
"Hold" is active.
"Hold" status see display.
Current output signal
incorrect or different
than expected
Incorrect current assignment
Check current assignment: Check
whether you selected 0–20 mA or
4–20 mA
Incorrect signal assignment
Any current output can be assigned to
any measured value (pH1 or 2, Temp.
1 or 2, Delta pH)
Check under "PARAM" / current out-
put
Total load in current circuit too high
(> 500 ohms)
Disconnect output and measure cur-
rent directly on instrument
mA Meter for 0–20 mA DC
Error
Possible cause
Remedial action
Equipment needed,
spare parts
