Startup; Direction Of Rotation - Grundfos DWK O 6.50.075 Montage- Und Betriebsanleitung

12. Startup

Warning
Before starting work on the pump, make
sure that the fuses have been removed or
the mains switch has been switched to 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.
Procedure
1. Remove the pump from the system.
2. Check that the impeller can rotate freely. Turn the
impeller by hand.
3. Check the condition of the oil in the oil chamber.
See section 14.2.2 Inspection of seal
4. Check whether the monitoring units, if used, are
operating satisfactorily.
5. Check the setting of the level pickups, float
switches or electrodes.
6. Check the direction of rotation, see section
12.1 Direction of rotation.
7. Reinstall the pump in the system.
8. Switch on the power supply.
9. Open the isolating valves, if fitted.
10. Check that the motor is 2/3 covered with liquid. If
the liquid level is below that, add liquid to the
tank until the minimum level is reached.
11. Vent the pump by tilting it by means of the lifting
chain and let trapped air escape.
12. Let the pump run briefly, and check if the liquid
level is falling. A correctly vented pump will
quickly lower the liquid level.
13. Start the pump.
In case of abnormal noise or vibrations
from the pump or power/water supply
failure, stop the pump immediately. Do not
Caution
attempt to restart the pump until the cause
of the fault has been found and the fault
corrected.
14

12.1 Direction of rotation

Note
Check the direction of rotation in the following way
every time the pump is connected to a new
installation.
Procedure
1. Let the pump hang from a lifting device, e.g. the
hoist used for lowering the pump into the tank.
2. Start and stop the pump while observing the
movement (jerk) of the pump. If connected
correctly, the impeller will rotate clockwise when
viewed from above. Consequently, when started,
the pump will jerk counter-clockwise. See fig. 8. If
the direction of rotation is wrong, interchange any
sensor.
two phases in the power supply.
Fig. 8
The pump may be started for a very short
period without being submerged for
checking of the direction of rotation.
Checking the direction of rotation