Startup; Direction Of Rotation - Grundfos DPK.10.50.075 Installation And Operating Instructions Manual

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. 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.
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 sensor.
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 electricity 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.
Caution
Do not attempt to restart the pump until
the cause of the fault has been found
and the fault corrected.
12.1 Direction of rotation
The pump may be started for a very
short period without being submerged
Note
in order to check the direction of
rotation.
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. 9.
If the direction of rotation is wrong, interchange
any two phases in the power supply.
Fig. 9 Checking the direction of rotation
11