DP Pumps Hydro-Unit Utility Line F, Installation & Operating Manual

Page: 49 / 96

49 / 96
8.2 Servicing/Inspection
8.2.1 Supervision of operation
CAUTION
Increased wear due to dry running
Damage to the pump set!
Ø Never operate the pump set without liquid fill.
Ø Never close the shut-off element in the suction line and/or supply line
during pump operation.
CAUTION
Impermissibly high temperature of fluid handled
Damage to the pump!
Ø
Prolonged operation against a closed shut-off element is not permitted
(heating up of the fluid).
Ø Observe the temperature limits in the data sheet and in the section on
operating limits.
While the pump is in operation, observe and check the following:
– If activated, check the functional check run.
– Measure the actual start-up pressure and stop pressure of the pump sets with a
pressure gauge. Compare the values with the specifications on the name plate.
– Compare the pre-charge pressure of the accumulator with the recommended data.
[
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Section 8.3, Page 50]
– Check the rolling element bearings for running noises.
Vibrations, noise and an increase in current input occurring during unchanged operating
conditions indicate wear.
– Monitor the functions of auxiliary connections, if any.
Also see
2
Setting the pre-charge pressure [
}
50]
8.2.2 Maintenance schedule
Table 20: Overview of maintenance work
Maintenance interval Servicing/maintenance work
At least once a year Check the pump sets for smooth running. Check the mechanical seal for integrity.
Check the shut-off elements, drain valves and check valves for proper functioning and
tightness.
If fitted, clean the strainer in the pressure reducer.
If fitted, check the expansion joints for any wear.
Verify the pre-charge pressure. Check the accumulator for integrity. [
ð
Section 8.3, Page 50]
Check the automatic switching functionality.
Check the cut-in levels and cut-out levels.
Check the inflow, inlet pressure, dry running protection and pressure reducer.