Pump Controllers; Thermal Switches; Start-Up; General Start-Up Procedure - Grundfos SEG Instrucciones De Instalación Y Funcionamiento

9.3 Pump controllers

Controllers incorporating motor protection relay and control unit
are available from Grundfos:
When installing the level switches, observe the following points:
• 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.
• 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 pit.
• The high-level alarm switch, if installed, must always be
installed about 4 inches (10 cm) above the start level switch;
however, the alarm must always be given before the liquid
level reaches the inlet pipe to the pit.
For further settings, see the installation and operating instructions
for the pump controller selected.

9.4 Thermal switches

All SEG pumps have two sets of thermal switches incorporated in
the stator windings.
The thermal switch in circuit 1 (T1-T3) will break the circuit at a
winding temperature of approx. 302 °F (150 °C).
In single-phase, 2 hp (1.5 kW) pumps, the thermal switch will
break the circuit at a winding temperature of approx. 257 °F (125
°C).
Warning
After thermal cutout, explosion-proof pumps must be
FM
restarted manually. The thermal switch (circuit 2)
must be connected for manual restarting of these
pumps.
Note
Note
This thermal switch must be connected for all 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.
Warning
The separate motor-protective circuit breaker or
FM
control box must not be installed in potentially
explosive environments.

10. Start-up

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
FM
Only Ex pumps must be started if the atmosphere in
the pit is potentially explosive.
Warning
It may lead to personal injuries or death to open the
clamp while the pump is operating.

10.1 General start-up procedure

Proceed as follows:
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
11.2 Oil change.
3. Check whether the monitoring units, if used, are operating
satisfactorily.
4. Check the setting of the float switches.
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.
In case of abnormal noise or vibrations from the
pump, other pump failure or power supply failure,
Caution
stop the pump immediately. Do not attempt to restart
the pump until the cause of the fault has been found
and the fault corrected.
Check the condition of the oil in the chamber after one week of
operation after replacement of the shaft seal. See section
11. Maintenance and service.
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