Operation; Switching Off; Switching On Again - Grundfos AQC-D12 Installation And Operating Instructions Manual

11.2 Operation

11.2.1 Switching on
See section 10.7 Switching on .
11.2.2 Operating state
Observe the installation and operating instructions of
Caution
the measuring amplifier and the device controlled!
For information on operation of the measuring cell in
the operating state, please see the installation and
Note
operating instructions of the relevant measuring
amplifier.
The measuring cell may be damaged if the reference
Caution
electrode (K) is not connected, and the electricity
supply is switched on!
11.2.3 Adjusting / setting the quantity of sample water
A correct measurement can only be taken, if the quantity of
sample water is within a defined range. This range is from 200 to
800 rotations/minute of the cleaning wing.
• Set the quantity of sample water with the regulation (G) so that
the measuring amplifier shows a sample water flow rate of 200
to 800 rotations/minute. The bar in the display of the
measuring amplifier shows the range. The exact speed can be
taken from the service menu.
Observe the installation and operating instructions of
Caution
the measuring amplifier and controller!
The delay time of the measuring cell can be reduced
Note
by increasing the sample water flow rate.

11.3 Switching off

To avoid a dosing error, the device controlled must
be switched off each time the measuring system is
Caution switched off.
Observe the installation and operating instructions of
the measuring amplifier and the device controlled!
11.3.1 Short-term stop (up to one week)
1. Close and/or switch off the device controlled.
2. Wait until the display of the measuring amplifier is at zero.
3. Switch off the electricity supply to the measuring amplifier.
4. Close the connection to the sample water inlet (E) and outlet
(F).
To protect the electrodes, do not drain the water!
Make sure that the water level in the measuring cell
Caution
is sufficiently high for the reference electrode (K) to
be immersed at least 2 cm during device stop.
11.3.2 Long-term stop
1. Close and/or switch off the device controlled.
2. Wait until the display of the measuring amplifier is at zero.
3. Switch off the electricity supply to the measuring amplifier.
4. Close the connection to the sample water inlet (E) and outlet
(F).
5. Open the sampling cock (I), and drain water.
6. Remove the measuring electrode (J), clean and store dry.
7. Remove the reference electrode (K), and remove the pH
electrode (A) and redox electrode (B), if applicable. Fit thread
protection caps, and clean the electrodes.
8. Fit protective caps on the electrodes. The protective caps
must be filled with 3-molar potassium chloride solution.
Observe the installation and operating instructions of
Caution
the electrodes!
9. Store electrodes with protective caps in a dry place. If they are
stored for an extended period of time, it may be necessary to
add 3-molar potassium chloride solution after a while.
10. Before starting up again, and if it is very dirty, clean the whole
measuring cell. See section

11.4 Switching on again

Observe the installation and operating instructions of
Caution
the measuring amplifier and the device controlled!
11.4.1 After short-term stop
1. Open the connection to the sample water inlet (E).
2. Open the connection to the sample water outlet (F).
3. Check the quantity of sample water.
4. Switch on the measuring amplifier.
Let the system run for at least two hours to avoid
Caution
faulty measurements and calibrations!
5. Take a reference measurement.
6. Recalibrate, if necessary. See section
parameters Cl , ClO , O .
2 2 3
7. Switch on the device controlled, if applicable.
11.4.2 After long-term stop / inspection
If the measuring cell has been switched off for a long period of
time or has been emptied, for instance for inspection, it is
necessary to start up the measuring cell. See section
10.6 Checks prior to start-up and
12. Maintenance .
10.8 Calibrating the
10.7 Switching on .
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