En
gl
is
h (
G
B)
12
When installing the level switches, the following
points should be observed:
•
To prevent air intake and vibrations, install the
stop level switch in such a way that the pump is
stopped before the liquid level is lowered below
the middle of the motor housing.
•
The start level switch should be installed 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.
•
The high-level alarm switch, if installed, should
always be installed about 10 cm above the start
level switch; however, the alarm must always be
given before the liquid level reaches the inlet pipe
to the tank.
For further settings, see the installation and
operating instructions for the pump controller
selected.
8.4 Thermal switches
All SEG pumps have two sets of thermal switches
incorporated in the stator windings.
Thermal switch, circuit 1 (T1-T3), breaks the circuit
at a winding temperature of approx. 150 °C.
Thermal switch, circuit 2 (T1-T2), breaks the circuit
at a winding temperature of approx. 170 °C (three-
phase pumps) or 160 °C (single-phase pumps).
The maximum operating current of the thermal
switches is 0.5 A at 500 VAC and cos
φ
0.6.
The switches must be able to break a coil in the
supply circuit.
In the case of standard pumps, both thermal
switches can (when closing the circuit after cooling)
generate automatic restarting of the pump via the
controller.
9. Startup
9.1 General startup procedure
1. Remove the fuses, and check whether the
impeller can rotate freely. Turn the grinder head
by hand.
2. Check the condition of the oil in the oil chamber.
See also section
.
3. Check whether the monitoring units, if used, are
operating satisfactorily.
4. Check the setting of the air bells, float switches
or electrodes.
5. Open the isolating valves, if fitted.
6. Lower the pump into the liquid and insert the
fuses.
7. Check whether the system has been filled with
liquid and vented. The pump is self-venting.
8. Start the pump.
After one week of operation after replacement of the
shaft seal, the condition of the oil in the chamber
should be checked. See section
.
Caution
The pump must not run dry.
An additional level switch must be
installed to ensure that the pump is
stopped in case the stop level switch is
not operating.
Stop the pump when the liquid level
reaches the upper edge of the clamp on
the pump.
Note
This thermal switch must be connected
for all pumps.
Warning
Before starting work on the pump,
make sure that the fuses have been
removed or the mains switch has been
switched off. Make sure 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.
Warning
The pump must not be started if the
atmosphere in the tank is potentially
explosive.
Warning
It may lead to personal injuries or
death to open the clamp while the
pump is operating.
Caution
In case of abnormal noise or vibrations
from the pump, other pump failure or
power supply failure, stop the pump
immediately. Do not attempt to restart
the pump until the cause of the fault
has been found and the fault corrected.
