Maintenance And Service; Mechanical Maintenance; Motor - Grundfos Multilift M Montage- Und Betriebsanleitung

10. Maintenance and service

The Multilift M requires a minimum of maintenance.
Warning
Before carrying out maintenance and service on
lifting stations used for pumping liquids which might
be hazardous to health, make sure that the lifting
station has been thoroughly flushed with clean water
and that the outlet pipe has been drained. Rinse the
parts in water after dismantling. Make sure that the
isolating valves have been closed. The work must be
carried out in accordance with local regulations.
Warning
Before making any connections in LC 221 or working
on lifting stations, make sure that the power supply
has been switched off and that it cannot be
accidentally switched on.
According to EN 12056-4, lifting stations must be checked at the
following regular intervals:
• every 12 months in single-family houses
• every 6 months in multi-family dwellings
• every 3 months in commercial and industrial applications.
During the check, local regulations must be observed.
The periodic checks of the lifting station must be carried out by
authorised personnel and must comprise electrical and

mechanical maintenance.

Check the following points:
• Outlet and inlet connections
Check all connections to the lifting station for tightness and
leakages. Make sure that weight from the inlet, outlet and vent
pipes does not rest on the tank. Long pipe sections, valves,
etc. must be supported.
• Power consumption
See nameplate.
• Cable entry
Make sure that the cable entry is watertight and that the
cables are not bent sharply and/or pinched.
• Pump parts
Remove eight screws, dismantle the pump from the tank and
check that the vent hole of the pump housing is clear.
When the pump is mounted again, we recommend replacing
the O-ring between pump and tank. Make a test run with clean
water. In case of noise, vibration or abnormal running, contact
Grundfos.
• Ball bearings
Check the shaft for noisy or heavy operation.
Replace defective ball bearings. A general overhaul of the
pump is usually required in case of defective ball bearings or
poor motor function. This work must be carried out by the
manufacturer or an authorised service workshop.
Cleaning the non-return valve (if required)
Proceed as follows:
1. Close the isolating valves in the outlet pipe and in the inlet
pipe (if fitted) or drain the outlet pipe by tightening the drain
screw on the side of the non-return valve. See fig. 4.
2. Clean the non-return valve via its inspection cover.
Replace the gasket of the inspection cover when
reassembling the non-return valve.
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10.1 Mechanical maintenance
• Remove possible deposits and/or sludge build-up in the
collecting tank.
• Remove any blockages on the inlet side of the lifting station.
A blockage will typically be a large solid object.
• Check and replace the gaskets of connections at valves, etc.,
if necessary.
• Check the tank for cracks and deformations. These may occur
in case of faulty assembly and therefore excessive stress on
the tank.
Note: The above list is not complete. The lifting station may be
installed in environments which require thorough and frequent
maintenance.

10.2 Motor

Check the direction of rotation of the pump in the following way:
• Turn off the power.
• Unscrew the lifting eye and the nut on top of the motor.
See fig. 29.
• The top of the motor shaft is now visible. See fig. 30.
Check that rotor and impeller can be turned freely by turning
the shaft with a large slotted screwdriver.
Fig. 29 Lifting eye
Fig. 30 Top of slotted motor shaft