Preparations For Starting Up; Start And Stop Levels For Auto-Coupling Installations; Start And Stop Levels For Dry Installations - Grundfos S2 Instrucciones De Instalación Y Funcionamiento

5.1 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 has been filled with
pumped liquid.
In dry installations with cooling jacket, the cooling
jacket must always be filled with pumped liquid
during operation. Ensure this by venting before the
first startup.

5.1.1 Start and stop levels for auto-coupling installations

The start and stop levels are specified during the design stage.
Always check that the start/stop levels function and possibly alter
them when starting up the pump in order to ensure good
operation.
Stop levels
Fig. 16 Stop levels for auto-coupling installations
In the case of an FM pump, install an additional level
FM
sensor for the stop level.
FM pumps without a cooling jacket, installation type
FM
S, must always be fully submerged.
14
Set the stop level according to fig. 16, so that the flow velocity in
the pit will increase towards the end of the working cycle. In pits
with several different stop levels, such as in frequency-controlled
installations, program the control sequence to pump down to the
lowest stop level at least once per 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 foreseen, but must be confirmed through trials during startup.

5.1.2 Start and stop levels for dry installations

Stop levels
The stop level setting 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 in order 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. 17.
Installation type S
(submerged
without cooling
jacket) and Ex
pumps
Installation type C
(submerged with
cooling jacket)
G
S
D
1
F
Fig. 17 Vertical, dry installation (D)
D
p
Reduction
elbow