Fault Finding - Grundfos LC 221 Manual De Instrucciones

9. 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., make sure that the power supply has
been switched off and that it cannot be accidentally switched on.
Fault Cause
1. The pump(s) a) No power supply.
does/do not run.
b) The ON-OFF-AUTO selector switch is in
c) Control circuit fuses are blown.
d) The motor-protective circuit breaker has cut out
e) Motor/supply cable is defective or the
f)
g) The main board or the LCD board is defective.
2. The pump(s) is/are a) The level measurement fails. The sensor gives
starting/stopping too
frequently and even
if there is no inflow.
b) The operating time protection is activated, the
c) The thermal switch has cut out the pump.
3. One pump starts a) Test run 24 hours after last operation.
sometimes without
visible reason.
4. The tank is empty a) This is related to the measuring principles of
but the displayed
water level is
greater than 0 mm.
None of the indicator lights are on.
With battery backup: See section 4. Product
description.
position OFF ( ).
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 and/or F006.
wrong signal.
pump and time symbols are flashing, the red
LED is flashing and the display indicates fault
code F011 and/or F012. If the pump runs longer
than 3 minutes, a protection program of the
controller will stop the pump for 3 minutes and
the other pump will take over. At the next start
impulse, the first pump will be activated again.
If the venting problem persists, the pump will be
stopped after 3 minutes and so on.
Note: Normal operating times are up to
60 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
F005 and/or F006.
the sensor.
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 8.2 Checking the
level sensor), and start up again. Check the cable and
the connection on the controller board. If the signal is
still wrong, please call Grundfos service.
Replace the main board or the LCD board.
Check for possible leaks between pressure hose and
bulkhead fitting at the control cabinet. The pressure
hose must be inserted to the stop (approx. 15 mm).
Clean the level sensor (see section 8.2 Checking the
level sensor).
Check that the discharge valve is open. Check the
venting of the pump housing. Clean the vent hole if it is
blocked.
Allow the pump to cool down. After cooling down, the
pump will restart automatically unless the LC 221 has
been set to manual restarting. See section
5.4 Connecting the level sensor. 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 10. Technical data.
See also section 8.2 Checking the level sensor.
No action necessary. It is a safety function that prevents
the shaft sealing from seizing up.
No action necessary. See chapter 4.2 Level sensor.
19