English (GB)
12
If the inlet is located too high relative to the liquid level or with a
high flow velocity, it may cause entrainment of air and the
formation of eddies in the liquid when entering into the pit. Air
entrained in the liquid tend to remain inside the pump impeller,
where the centrifugal force makes it accumulate around the
impeller hub. This may lead to increased power requirements and
lowered performance and efficiency. The risk of cavitation and
pump vibrations also increases. If the amount of air in the pump is
very high, the pump may stop operating.
Fig. 21
Avoided location of retrofitted inlet
5. Installing the pump(s)
For installation and startup of the pump(s), see the installation
and operating instructions for the pump.
6. Installing the level switches
See the installation and operating instructions for the level control
system.
When installing the level switches, observe the following points:
• To prevent air intake and vibrations in the pump, the stop level
switch must be fitted in such a way that the pump is stopped
before air is sucked into the pump.
• In the case of one-pump operation, the start level switch must
be installed in such a way that the pump is started at the
required level; however, the pump must always be started
before the liquid level reaches the lower edge of the bottom
inlet pipe.
• In the case of multipump operation, the start level switches
must be installed in such a way that pumps are started before
the liquid level reaches the lower edge of the bottom inlet pipe.
• The high-level alarm switch must always be installed about
100 mm above the start level switch; however, the alarm must
always be given before the liquid level reaches the inlet pipe.
For further settings, see the installation and operating instructions
for the level switch selected.
TM
07
12
48
12
18
DANGER
Crushing hazard
Death or serious personal injury
- Do not stand under or close to a suspended load.
Use only certified, CE marked lifting chains.
Lower the pump carefully into the pit in order to avoid
damage to the pump and the pit.
DANGER
Crushing hazard
Death or serious personal injury
- Make sure the lifting equipment is rated for the
weight of the pump and is approved and
maintained according to local regulations.
Chains supplied by Grundfos are marked with
maximum load and production date.
Do not exceed the maximum load.
Maintain the chain according to local regulations. We
recommend that you check chains and shackles
supplied by Grundfos at least once a year for cracks,
corrosion or other irregularities. If you find any
defects, replace the chain or shackles.
CAUTION
Electric shock
Minor or moderate personal injury
- Make sure the float switches are connected
properly and that the cables are not bent or
sharply pinched.
If the pit is equipped with an AUTO
ADAPT
-controlled
pump, an external level controller is not needed.
Summary of Contents for PS.G Series
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