Electrodes; Air Bells; Pressure Transducer; Other Types Of Level Control Equipment - Grundfos PS.R.05 Montage- Und Betriebsanleitung

6.4 Electrodes

If electrodes are used for level control, note that the electrodes
come in a standard lengths of 1 m. When they are installed, their
lengths must therefore be adjusted so that they are activated at
the correct levels.
If possible, bend the electrodes away from each other so that
paper and similar items cannot get stuck between the electrodes
and disturb the signal.
When they have been shortened to the desired length, strip 10 to
15 mm of the lower end of the electrodes.
The electrodes come with a 10 m cable.
Fig. 18 Electrodes in a pit with one pump
Fig. 19 Electrodes in a pit with two pumps

6.5 Air bells

Air bells are pulse generators for the pressure switches of the
pump controller and function by means of pneumatic pressure
changes. The pressure changes when the liquid level changes in
the air bell. The air bells are connected to the pressure switches
of the controller by means of pressure hoses.
CU 211
Fig. 20 Air bells in a pit with one pump
Alarm: 32
Start: 22
The stop level
depends on the
pump type
Common: 11
Alarm: 42
Start : 32
2
Start : 22
1
The stop level
depends on the
pump type
Common: 11
CU 211

6.6 Pressure transducer

If a pressure transducer is used, install it a protective pipe in
order to prevent contamination and deposits.

6.7 Other types of level control equipment

See the installation and operating instructions for the equipment.

7. Electrical connection

See the installation and operating instructions for the pump and
the pump controller.
The electrical installation must be carried out by an
authorised person in accordance with local
regulations.
WARNING
Electric shock
Death or serious personal injury
- The pump or pump controller must be connected
to an external emergency stop.
If the main switch is used as emergency stop, it
must fulfil EN 60204-1, 10.8.4.
DANGER
Electric shock
Death or serious personal injury
- Before starting any work on the product, make
sure that the power supply has been switched off
and that it cannot be accidentally switched on.
Do not install Grundfos control boxes and the free
end of the supply cable inside the pumping station.

7.1 Installing the cables

The cables for the level switches and the pump(s) can be led into
the pit in different ways. Often the cables are led into the pit
through a cable entry in the side of the pit. If the pit is equipped
with a vent pipe, the vent pipe can be used as cable entry.
When installing or removing the pump, make sure
not to pinch or damage the cables.
When the pump and cables have been installed,
suspend the cables in such a way that any stress is
relieved from the cables.
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