Startup; Resetting The Pump - Grundfos DP 10 Installation And Operating Instructions Manual

Checking the direction of rotation
Check the direction of rotation in one of the following
ways every time the pump is connected to a new
installation.
Procedure 1:
1. Start the pump and measure the quantity of liquid
or the outlet pressure.
2. Stop the pump and interchange two phases in the
power cable.
3. Restart the pump and measure the quantity of
liquid or the outlet pressure.
4. Stop the pump.
5. Compare the results taken under points 1 and 3.
The connection which gives the larger quantity of
liquid or the higher pressure is the correct
direction of rotation.
Procedure 2:
1. Let the pump hang from a lifting device, such as
the hoist used for lowering the pump into the pit.
2. Start and stop the pump while observing the
movement (jerk) of the pump.
3. If connected correctly, the pump will jerk in the
opposite direction of the direction of rotation. See
fig. 8.
4. If the direction of rotation is wrong, interchange
two phases in the power cable. See fig.
Fig. 8 Jerk direction
14

4.4 Startup

The pump must not run dry.
If the atmosphere in the pit is potentially
explosive, use only pumps with Ex
approval.
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
corrected.
Proceed as follows:
1. Remove the fuses and check that the impeller
can rotate freely. Turn the impeller 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.
2 or 3.
5. Open the isolating valves, if fitted.
Auto coupling: It is important to grease the
gasket of the guide claw before lowering the
pump into the pit.
6. Lower the pump into the liquid and insert the
fuses.
Auto coupling: Check that the pump is in the
right position on the auto-coupling base unit.
7. Check that the system has been filled with liquid
and vented. The pump is self-venting.
8. Switch on the power supply to the pump. When
power is on, the pump will start and pump down
to the dry-running level. This process can be
used to check that the pump functions correctly.
After one week of operation or after replacement of
the shaft seal, check the condition of the oil in the oil
chamber. See section
the product.

4.5 Resetting the pump

To reset the pump, switch off the power supply to the
pump for one minute, and switch it on again.
8.4 Oil check and oil change.
8. Servicing and maintaining