English (GB)
15
12. Fault finding
Observe the installation and operating instructions of the measuring amplifier and controller!
Fault
Cause
Remedy
1. No display, no measuring
cell current.
a) Disinfection or oxidation agent missing in sample
water.
Check the concentration using a reference
measurement.
Activate dosing.
b) Poor contact of counter-electrode.
Check the contact, and replace the socket or
plug, if necessary.
c) Interruption in electrode cable.
Reestablish
connection, and replace damaged
cables, if necessary.
d) Sample water flow too low or missing.
Clean the filter, and check the flow and sample
water inlet pressure.
e) Measuring electrodes faulty.
Replace the measuring electrode.
2. Measured value too low.
a) Measuring electrodes contaminated or made
passive by deposits.
Dismantle, clean or replace the measuring
electrode.
b) Temperature has dropped
since calibration.
Recalibrate.
c) Warming-up time too short prior to calibration.
Observe the warming-up time prior to
calibration, then recalibrate.
d) Quantity of sample water set too low.
Check and adjust the quantity of sample water.
Check the filter and clean, if necessary.
e) Unsuitable chlorination agent.
Only use suitable chlorination agents, and
contact your Grundfos partner.
f)
Faulty reference measurement.
Check the reference measurement, and analyse
the sample water.
g) Cleaning motor blocked.
Gently
loosen the measuring electrode and
re-position.
Replace the magnetic stirring stone, cleaning
balls or slide disk.
h) Cleaning motor does not move.
Check the electrical
tension, and replace the
motor unit, if necessary.
3. Measured value too high. a) Temperature has risen since calibration.
Recalibrate.
b) Interference by other oxidation agents in sample
water.
Analyse the sample water.
Check the used chemicals.
4. Measured value
unstable.
a) Interferences on signal lines.
Check the screen.
b) Air bubbles in measuring chamber.
Place the electrode correctly.
Replace the magnetic stirring stone, if
necessary.
c) Reference electrode diaphragm blocked.
Clean the diaphragm, and replace the
measuring electrode, if necessary.
d) Siphon effect at sample water outlet.
Reduce the sample water quantity, and check
that the correct layout of is used for the outlet
tube.
Summary of Contents for AQC-D4
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