Operation; Maintenance, Inspection And Overhaul; Maintenance; Current And Voltage - Grundfos DPK.10.50.075 Instrucciones De Instalación Y Funcionamiento

13. Operation

S1, continuous operation:
In this operating mode, the pump can operate
continuously without being stopped for cooling.
See fig. 11. Being completely submerged, the pump
is sufficiently cooled by the surrounding liquid.
See also fig. 1.
P
Fig. 11 S1 continuous operation
S3, intermittent operation:
Operating mode S3 means that within 10 minutes the
pump must be in operation for 4 minutes and
stopped for 6 minutes. See fig. 12.
For this operating mode, the pump must be partly
submerged in the pumped liquid, i.e. the liquid level
must reach at least up to the middle of the motor
housing. See fig. 1.
P
Operation
4 min
Stop
Fig. 12 S3 intermittent operation
t
6 min
10 min
t
14. Maintenance, inspection and
overhaul

14.1 Maintenance

The life of the pump depends largely on the
operating conditions, so we strongly recommend
daily inspection and periodic servicing in order to
guarantee maximum product lifetime.

14.1.1 Current and voltage

Check the pump current and voltage. If the ammeter
reading exceeds the rated value, or is far lower than
the rated value, there is a problem. The voltage
should be stable within ± 5 % of the rated value
throughout the operational period.

14.1.2 Vibration

Check that the pump is operating smoothly and
without vibrations.

14.1.3 Outlet pressure and flow rate

Check the outlet pressure and flow rate
(if a flowmeter is available) at least once a month.
Declining performance can indicate the need for an
overhaul. Regardless of performance, the pressure
and flow rate should be stable, and rapidly changing
pressure or flow rate indicate system problems on
the inlet or outlet side.

14.1.4 Insulation resistance

Check the insulation resistance of the motor at least
once a month.
If the insulation resistance has declined sharply
since the previous reading, this is an indication of
impending insulation failure, and the pump should be
scheduled for service even though the insulation
resistance may still be over 10 megohms.
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