Preparations For Starting Up; Level Of Pumped Liquids - Grundfos S Serie Manual Del Usuario

8.1 Preparations for starting up

DANGER
Rotating elements
Death or serious personal injury
‐
Before manual startup or changeover to automatic
control, make sure that no persons are working on or
near the pump.
Before the first startup and after a long standstill period, make sure
that the pump is filled with the pumped liquid.
In dry installations with cooling jacket, the cooling jacket must
always be filled with the pumped liquid during operation. Ensure this
by venting before the first startup.

8.2 Level of pumped liquids

In case of an FM pump, install an additional level sensor
FM
for the stop level.
FM pumps without a cooling jacket, installation type S,
FM
must always be completely submerged.
To avoid air being sucked into the pump and to ensure adequate
cooling of the motor during operation, make sure to meet the
following minimum requirements:
• Installation type S:
For continuous operation, S1, the pump must always be covered by
the pumped liquid to the top of the motor.
• Installation type C:
The pump housing must always be covered by the pumped liquid.
8.2.1 Start and stop levels for auto-coupling installations
The start and stop levels are specified during the design stage.
Always check that the start or stop levels function and possibly alter
them when starting up the pump to ensure proper operation.
Stop levels
Stop levels for auto-coupling installations
Pos. Description
Installation type S (submerged without cooling jacket)
S
and Ex pumps
C Installation type C (submerged with cooling jacket)
22
Set the stop level according to fig. Stop levels for auto-coupling
installations, so that the flow velocity in the pit increases towards
the end of the working cycle. In pits with several different stop
levels, set the control sequence to pump down to the lowest stop
level at least once a day to clean out the bottom of the pit.
The stop levels are determined by the motor submergence required
to ensure cooling, to prevent cavitation or to avoid air being sucked
into the pump inlet. The lowest level cannot always be predicted,
but must be confirmed through test runs during startup.
8.2.2 Start and stop levels for dry installations
Stop levels
The stop level for dry-installed pumps depends on the inlet pipe
height, shape and flow velocity. Set the stop level approximately
one inlet pipe diameter above the inlet pipe. The final stop level
must be confirmed through test runs during startup.
Start levels
In pits with dry-installed pumps, set the starting level above the
pump housing to ensure that the cooling jacket is filled up before
the pump starts pumping. For vertical pumps, this height may be
considerable and must be set with a margin according to fig.
Vertical, dry installation (D).
Vertical, dry installation (D)
Horizontal pumps do not require special considerations for the start
level, if the inlet pipe is designed to prevent air pockets from
S
forming. See fig. Switches and sensors.
C
Horizontal, dry installation (H)
G
S
D
1
45°
F
S
D 1
45°
F
Z
E
D
p
Y
E