Checking The Direction Of Rotation; Start Up - Grundfos S2 Série Mode D'emploi

Minimum stop level
Minimum distance between the bottom of the
pit and the lowest part of the inlet pipe
Minimum start level
Minimum stop level for Ex pumps
Reduction elbow
Eccentric reducer
S is the minimum stop level. The minimum distance, S, above the
inlet pipe is required to avoid the formation of vortices at the inlet
pipe and to avoid air being sucked into the pump. Air in the pumped
liquid may cause vibrations, cavitation and loss of pump
performance.
G is the minimum start level of a dry-installed, vertical pump, if no
other actions are taken to ensure that the pump housing is filled
with the pumped liquid when the pump is started. Other possible
actions:
• Use a vacuum pump to suck liquid into the pump housing. This
requires an isolating valve on the outlet side.
• Install a non-return valve in the outlet pipe after the first startup.
This prevents the draining of the pump housing between
running periods.

8.3 Checking the direction of rotation

Start an unsubmerged pump only for a few seconds to
check the direction of rotation.
A label with an arrow on the pump housing indicates the correct
direction of rotation. The direction of rotation is clockwise.
DANGER
Crushing hazard
Death or serious personal injury
‐
Do not touch the pump when starting it up.
Make sure that the bottom of the pit is clear of debris
before startup to avoid material being sucked into the
impeller.
Installation types S, C and T:
Proceed as follows:
1. Lift the pump approximately 0.8 - 2 in (2-5 cm) from the ground
or base using a lifting chain and a crane.
2. Start and run the pump for a few seconds.
3. Observe the jerk of the pump. If the pump jerks
counterclockwise, the direction of rotation is correct.
In case the direction of rotation is wrong, interchange two phases in
a power cable.
Installation types Dand H
Check the duty point to determine the direction of rotation.

8.4 Start up

For FM models in dry installations (version D and H),
FM
connect an external earthing.
Before installation and the first startup of the pump, check
FM
the condition of the cables to avoid short circuits.
Proceed as follows:
1. Lock the main switch in position 0.
2. Check the oil level in the oil chamber.
3. Check that the impeller can rotate freely.
4. Check whether the monitoring units, if used, are operating
S = D
1
properly.
F = 0.5 x D
1
5. Open the isolating valves, if fitted.
G = D 6. Pumps in installation types S and C: Make sure that the
p
pump is properly connected to the auto coupling.
E
7. Make sure that the pump is submerged in the liquid.
Y
8. Pumps in installation types D and H: Make sure that there is
Z
liquid in the pit and the pump housing and cooling jacket are
filled with the pumped liquid. Open the vent valve on the top of
the cooling jacket, before or during the startup, until water
comes out of the valve. Then close the valve. Pumps in
installation type C: The vent valve must always be open, also
during operation. Check the setting of the level switches.
Pumps in installation type ST: Make sure that the pump is
properly seated in the column pipe and secured against rotation.
9. Start the pump, and check the operation for abnormal noise or
vibrations.
10. After startup, establish the actual pump duty point as accurately
as possible.
Always operate the pump in accordance with established routines
with scheduled checks of pump monitoring equipment and
accessories. Make sure that the pump and equipment settings
cannot be changed by unauthorized persons.
In case of abnormal noise or vibrations, stop the pump
immediately. Do not restart the pump until the cause of
the fault is found and eliminated.
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