ProMinent DULCOTROL, General Operating Instructions

Page: 53 / 144

Pr o Minent
®
Page 53
Operation Note text Symbol Effect Alarm with ack- Remarks Remedy
on metering on control nowledgement
Pause contact Pause Stop Stop No/Yes* No further fault check –
Pause/Hold PI-part
frozen
Stop button Stop Stop Stop No Relay drops out –
During calibration sensor Basic load Stop in No No error processing of –
+ Feed complete measured variable
forward operating
control menu
Sensor slope too low Slope low 25% > sensor of slope Check sensor,
Sensor slope too high Slope high Basic load Stop No > 300% norm slope replace if necessary
H
2
O
2
-value <2 % measuring range H
2
O
2
too low < 2 % from meas. range
Zero point Zero point low Basic load Stop No Signal < 3 mA Check sensor/cable
Zero point high Signal > 5 mA Repeat calibration
in H
2
O
2
-free water
During servomotor setting
Position feed back wrong Direction check Without correct Check connection of relay,
Upper position <40 % max. value Final value small adjustment the last potentiometer
Lower position >30 % range Final value big valid values are still used Adjust the operation region
of the servomotor correctly
*dependent on whether “Alarm on” or “Alarm off” is set in “General settings”
Sensor: Troubleshooting
Troubleshooting includes the complete measuring station. This consists of
1) Measuring/control equipment
2) Electrical cable and connections
3) In-line probe housing and hydraulic connections
4) Sensor
Possible causes for faults shown in the table below mainly refer to the sensor. Before beginning
to look for any faults, you should ensure that all operating instructions have been carried out in
accordance with the Technical data:
a) H
2
O
2
content in accordance with the measurement range
b) Sample water temperature 0 - 50 °C and constant
c) Flow rate 30 - 60 l/h
You can use the sensor simulator (DULCOMETER
®
simulator order no. 1004042) to locate the
fault in the measuring and control system. The operating instructions manual for the
DULCOMETER
® D1C measured value H
2
O
2
gives full details on how to locate a fault in the
measuring and control equipment.
Where there are major discrepancies between the measured values of the sensor and the meas-
ured value of the reference methods, you should fi rst consider all possible faults relating to the
reference methods. You should repeat the reference measurement several times if necessary.
H
2
O
2
Fault
Sensor cannot be
calibrated and measured
value of the sensor is
greater than the reference
measurement
Sensor cannot be
calibrated and measured
value of the sensor is
smaller than the reference
measurement
Possible cause
Running-in time too short
Diaphragm cap damaged
Short circuit in the
signal cable
Interfering substances
Running-in time too short
Coating/deposits on
the diaphragm cap
No sample water fl ow
Air bubbles outside
on the diaphragm
Harmful substances
in sample water
Coating/deposits (mangan-
ese, iron oxide) at the
diaphragm cap
Remedy
See “Running-in time”
Change diaphragm cap;
run in the sensor, calibrate
Locate the short circuit and
remove
Contact ProMinent
See “Running-in time”
Clean or change diaphragm
cap; run in the sensor,
calibrate
Correct the fl ow
Increase the fl ow within the
permitted levels
Consult ProMinent
Clean or change diaphragm
cap; run in the sensor,
calibrate
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