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8.5 Cleaning the sensors
The cleaning intervals below are stated as guidelines
and must be adapted to the pit.
Cleaning intervals for non-explosion-proof
pumps
The following table lists the recommended cleaning
intervals for sensors in non-explosion-proof pumps.
These cleaning intervals are for guidance. We
recommend that you find the right cleaning level
based on experience and the composition of the
wastewater in the specific application.
Cleaning intervals for explosion-proof pumps
The following table lists the required cleaning
intervals for sensors in explosion-proof pumps.
Fig. 15
Position of level and dry-running
sensors
Proceed as follows:
See fig.
1. Level sensor (7):
Flush the sensor with clean water.
Dry-running sensors (10):
Flush the dry-running sensors with clean water
and clean them using a soft brush.
2. Switch on the power supply to the pump.
3. Check that the pump starts and pumps down to
the dry-running level.
Checking the functionality of the dry-running
sensors
1. Cover one dry-running sensor with a wet cloth.
2. Let the pump run and pump down to the dry-
running level.
– The pump must stop at the dry-running level.
3. Repeat this check with the other sensor.
Wastewater
containing
grease
Wastewater
containing dry
solid matter or
fibres
Wastewater
without grease,
dry solid matter
or fibres
3 months
6 months
12 months
Cleaning intervals of the sensors in
explosion-proof pumps are mandatory in
order to ensure that the pump is working
correctly.
After cleaning, both dry-running sensors
must be checked individually for proper
functioning.
If the dry-running sensors are not
functioning properly, there is a risk of dry-
running of the hydraulic part of the pump,
which can provoke ignition.
Wastewater
containing
grease
Wastewater
containing dry
solid matter or
fibres
Wastewater
without grease,
dry solid matter
or fibres
3 months
6 months
6 months
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To avoid damaging the sensors, do not use
other cleaning aids than those mentioned
in this booklet.
If the dry-running sensors are not covered
by liquid, the pump cannot start.
