ENGLISH
31
In tanks with one pump, install the
start level switch
in such a way that the pump is started at the required
level; however, the pump must always be started before the liquid level reaches the bottom inlet pipe to the
tank.
In tanks with two pumps, the
start level switch
for pump 2 must start the pump before the liquid level
reaches the bottom inlet pipe to the tank, and the start level switch for pump 1 must start this pump
correspondingly earlier.
If installed, always install the
high-level alarm switch
about 10 cm above the start level switch; however,
the alarm must always be given before the liquid level reaches the bottom inlet pipe to the tank.
For further information on electric panels and the respective use of level switches, contact
DAB Pumps.
Switches or sensors in potentially explosive environments must be certified for this
application.
Fig. 9
Start and stop levels
Make sure that the effective volume of the tank does
not become so low that the number of starts per hour
exceeds the maximum permissible number.
6.3 Thermal
switch
All FKV and FKC pumps have thermal protection incorporated in the stator windings (see wiring diagrams,
contacts k1, k2) See parag. 6.1.
The thermal switches are inserted in the motor windings and intervene by opening and interrupting the circuit
when an excessive temperature is reached in the windings (about 150°C).
Non explosion-proof pumps
For correct operation the thermal switch must be connected to a device for interrupting the power
supply circuit of the electropump. When the electropump has cooled, once the circuit of the thermal
switch has been reset, the device can automatically restart the pump.
Explosion-proof pumps
The device for interrupting the power supply circuit of explosion-proof pumps must not restart
the pump automatically. This ensures protection against over temperature in potentially
explosive environments.
6.4 Sensor (water in the oil) (not available for explosion-proof versions)
The sensor probe inserted in the oil chamber detects any presence of water in the oil when the water
percentage exceeds a predetermined value.
When the water level in the oil is reached, the probe closes the circuit between the sensor (contact S1 on wiring
diagram) and the equipotential contact of the pump.
The probe must be connected to a suitable device in the control panel; the device may give an acoustic alarm or
a luminous signal or, when requested, it may stop the electropump.
If the signal is activated you must stop the electropump, dismantle it and check the state of the oil, the
mechanical seals, and look for the causes of intervention.
7. START-UP
Before starting work on the pump, check that the main switch is off.
It must be ensured that the power supply cannot be accidentally switched on.
Make sure that all protective equipment has been connected correctly.
The pump must not run dry.
Fig. 9
Min. 10cm
Alarm
Start
Stop S1 operation
Stop S3 operation
