Fault Finding - Grundfos Multilift MSS Instrucciones De Instalación Y Funcionamiento

10. Fault finding

Warning
Before carrying out any work 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.
Before making any connections in LC 220 or working on lifting stations, etc., make sure that the power supply has been
switched off and that it cannot be accidentally switched on.
Fault Cause
1. The pump does not run. a) No power supply.
b) The ON-OFF-AUTO selector switch is in
c) Control circuit fuses are blown.
d) The thermal switch has cut out the pump.
e) Motor/supply cable is defective.
f)
g) The new DIP-switch setting does not work
2. The sensor signal is out a) Not all outlet valves are open.
of range.
b) There is a blockage in the tank or pump.
All pumps are started
c) The pump is not vented correctly. The pump
and high-level alarm is
on.
d) The lifting station is undersized.
3. The pump starts and a) The level sensor is blocked.
stops too frequently
even if there is no
b) The ventilation of the inner pump housing is
inflow.
4. The pump starts a) Test run 24 hours after last operation.
sometimes without
visible reason.
18
Without battery backup:
None of the indicator lights are on.
With battery backup:
See section 5.2 LC 220 controller.
position OFF ( ). See section
elements and indicator lights.
The power circuit board or the LED board is
defective.
correctly.
cannot build up pressure.
blocked and the pump cannot build up
pressure.
Remedy
Switch on the power supply.
Push the ON-OFF-AUTO selector switch into position
5.2.2 Control ON ( ) or AUTO ( ).
Check and eliminate the cause. Replace the control
circuit fuses.
Allow the pump to cool. After cooling, the pump will
restart automatically unless LC 220 has been set to
manual restarting (see section
If so, push the ON-OFF-AUTO selector switch into
position OFF ( ) for a short period.
Check and replace motor and cable, if necessary.
Replace the power circuit board or LED board.
Switch off the power supply to the controller for 1 minute
and switch it on again (normal procedure). See section
7.4 Setting of LC
Open all outlet valves.
Remove the blockage.
Remove any blockage from the vent hole underneath
the pump.
Recalculate the inflow parameters and compare the
result with the tank volume and pump performance. If
you need a new product, contact the nearest Grundfos
sales company.
Clean the level sensor (see section
level sensor).
Check the pump housing and remove any impurities.
No action necessary. It is a safety function that prevents
the shaft seal from seizing up.
7.4 Setting of LC
220.
9.2 Cleaning the
220).