9.3.3 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. 32 Air bells in a pit with one pump
9.3.4 Pressure transducer
If a pressure transducer is used, it should be installed in a riser
pipe in order to prevent contamination and deposits.
9.3.5 Other types of level control equipment
See the installation and operating instructions for the equipment.
10. Electrical connection and start-up
See the installation and operating instructions for the pump and
the pump controller.
Warning
The electrical installation should be carried out
by an authorised person in accordance with local
regulations.
Warning
The pump or pump controller must be connected
to an external emergency stop.
If a power supply circuit breaker is used as
emergency stop, it must fulfil EN 60204-1, 10.8.4.
Warning
Before starting work on the pump or valves,
make sure that the fuses have been removed or
the main switch has been switched off.
Make sure that the power supply cannot be
accidentally switched on.
Do not install Grundfos control boxes and the
Note
free end of the supply cable inside the pumping
station
CU 211
11. Maintenance
See the installation and operating instructions for the pump and
the pump controller.
We advise you to make all maintenance and
Note
service work when the pump is placed outside
the pit.
Warning
Do not enter and work inside PUST04-06-08-10.
Warning
Before entering PS.R.17, make sure that the
cover and safety grid are locked in open position
and that the pit is ventilated according to local
regulations. If not, do not enter the pit.
1
90°
3
Fig. 33 PS.R.17 opened
Warning
When entering the pit, wear safety harness and
use proper ladder and equipment for lifting
persons up from the pit.
All work in pits must be carried out according to
local regulations and supervised by at least one
person outside the pumping station.
Warning
When work is going on in an open, or in the
proximity of an open pumping station or valve
chamber, place proper warning signs and correct
safety barriers around the pit in order to avoid
that persons fall into the pit. The warning signs
must be visible from all directions.
2
90°
4
13