Operating Modes - Grundfos DP 10 Installation And Operating Instructions Manual

DANGER
Electric shock
Death or serious personal injury
- Before starting up the product for the
first time, check the power cable for
visible defects to avoid short circuits.
- If the power cable is damaged, it must
be replaced by the manufacturer, his
service agent or a similarly qualified
person.
- Make sure that the product is earthed
properly.
- Switch off the power supply and lock the
main switch in position 0.
- Switch off any external voltage
connected to the product before working
on it.
CAUTION
Biological hazard
Minor or moderate personal injury
- Flush the pump thoroughly with clean
water and rinse the pump parts in water
after dismantling.
Pits for submersible drainage and
effluent pumps may contain drainage or
effluent with toxic and/or disease-
causing substances.
- Wear appropriate personal protective
equipment and clothing.
- Observe the local hygiene regulations in
force.
CAUTION
Hot surface
Minor or moderate personal injury
- Do not touch the surface of the pump
while the pump is running.
Do not open the clamp while the pump is
running.
12

4.1 Operating modes

Do not start the pump if the atmosphere in
the pit is potentially explosive.
The pumps are designed for intermittent operation
(S3). When completely submerged in the pumped
liquid, the pumps can also operate continuously
(S1). See fig. 4.
Fig. 4 Operating levels
S3, intermittent operation
S3 operation is a series of 10-minute duty cycles
(TC). Each cycle has a 4-minute period of constant
load followed by a 6-minute period of rest. Thermal
equilibrium is not reached during the cycle. See fig.
5.
In this operating mode, the pump is partly
submerged in the surrounding liquid. The minimum
liquid level is at the top of the cable entry.
P
Operation
Stop
Fig. 5 S3 operation
S1
S3
t
TC