Fault Finding - Grundfos Conex DIA-1-A PA/HP Montage- Und Betriebsanleitung

12. Fault finding

See the installation and operating instructions for the Conex
Fault
1. Display permanently indicates
the same value.
2. Measured value unsteady
shortly after the start-up.
3. Measured value display very
unsteady.
4. Measured value too high or too
low.
®
DIA-1 / Conex
Cause
a) Cable breakage.
a) Running-in period of the
measuring cell too short.
a) Electrode not correctly inserted
into the flow armature (too
deep) or not sufficiently
covered by sample water.
b) Cable and/or connector
corroded.
a) Air bubbles in the electrolyte or
at the diaphragm.
b) Not enough electrolyte in the
diaphragm cap.
c) Large temperature fluctuations
for the sample water.
d) Deposits at the electrode.
e) Air bubbles in front of the
diaphragm (sample-water
side).
®
DIA-2Q!
Remedy
Replace the cable.
Observe the necessary running-in period of the measuring
cell: about one hour for peracetic acid and about three hours
for hydrogen peroxide.
When inserting the electrode in the flow armature, ensure that
the electrode is sufficiently covered by sample water.
• Replace the cable and connector respectively.
• Replace the electrode, if necessary.
• Uncover the valve of the diaphragm cap by lifting the
tubular ring (rubber band), and unscrew the diaphragm cap
• Let the air bubble out by carefully knocking on the
diaphragm cap.
• If these measures do not help, wash the diaphragm cap
with clean water, wet the diaphragm with the activation
fluid, fill up with electrolyte again, and repeat the
calibration.
• Uncover the valve of the diaphragm cap by lifting the
tubular ring (rubber band), and unscrew the diaphragm
cap.
• Fill up with electrolyte.
• Repeat the calibration.
Repeat the calibration.
• Uncover the valve of the diaphragm cap by lifting the
tubular ring (rubber band), and unscrew the diaphragm
cap.
• Wash the electrode, and dry it with dry disposable paper
tissue.
• Carefully clean the electrode (only the tip of the electrode)
with the special emery paper.
• Repeat the calibration.
Check that the water supply functions correctly.
15