Fault Finding - Grundfos Multilift M Serie Instrucciones De Instalación Y Funcionamiento

11. 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 discharge 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 the LC 221 or work on lifting stations, etc., it must be ensured 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 motor-protective circuit breaker has cut
e) Motor/supply cable is defective or the
f)
g) The module power circuit board or the LCD
2. The pump is a) The level sensor fails. The sensor gives
starting/stopping too
frequently and even if
b) The operating time protection is activated,
there is no inflow.
c) The thermal switch has cut out the pump.
3. Pump starts sometimes a) Test run 24 hours after last operation.
without visible reason.
32
None of the indicator lights are on.
With battery back-up:
See section 5.2 LC 221 controller.
position OFF ( ), see section 6. Operating
LC 221 controller.
out the pump (only relevant if a
motor-protective circuit breaker has been
installed). The pump symbol in the display is
flashing and the red indicator light for fault is
flashing. The fault indication in the display is
RELAY and the fault code is F018.
connections have become loose.
The fault indication in the display is
SENSOR and in the fault code is F005.
board is defective.
wrong signal.
the pump and time symbols are flashing, the
red LED is flashing and the display indicates
fault code F011. If the pump runs longer
than 3 minutes, a protection program of the
controller will stop the pump for 3 minutes
and start it again after cooling time.
This operating pattern will continue until a
stop signal from the sensor brings the pump
back to normal operation.
Note: Normal operating time is up to
20 seconds depending on duty point and
effective tank volume.
The pump and thermal switch symbols on
the display are flashing, and the red
indicator light for fault is permanently on.
The fault indication in the display is TEMP
and in the fault code is F007.
Remedy
Switch on the power supply or wait until the power cut is
over. During the power cut, drain the collecting tank with
diaphragm pump.
Push the ON-OFF-AUTO selector switch into position
ON ( ) or AUTO ( ).
Check and eliminate the cause. Replace the control
circuit fuses.
Check the pump and tank as well as the setting of the
motor-protective circuit breaker. If the pump is blocked,
remove the blockage. If the setting of the
motor-protective circuit breaker is wrong, readjust it
(compare the setting with the nameplate).
Check motor and supply cable. Replace cable or
retighten connections if necessary.
Clean the level sensor (see section 10.4 Cleaning the
level sensor), and start up again. Check the cable and
the connection on the control board. If the signal is still
wrong, please call Grundfos service.
Replace the PCB or LCD board.
Clean the level sensor
(see section 10.4 Cleaning the level sensor).
Check that the discharge valve is open. Check the
venting of the pump housing. If blocked, clean the vent
hole. See fig. 31.
Allow the pump to cool. After cooling, the pump will
restart automatically unless the LC 221 has been set to
manual restarting. See section 8.4 Setting of LC 221.
If so, the ON-OFF-AUTO selector switch must be
pushed into position OFF ( ) for a short period.
Check the inflow parameters and the non-return valve.
The risk is low, but if the non-return valve flap is leaky,
liquid in the discharge pipe can flow back.
A high number of starts without cooling time in between
over a longer period can cause thermal cut-out.
Consider S3 duty. See section 12. Technical data.
See also section 10.4 Cleaning the level sensor.
No action necessary. It is a safety function that prevents
the shaft seal from seizing up.