Faults, Causes And Remedies - Wilo FLA Série Notice De Montage Et De Mise En Service

10 Faults, causes and remedies

Faults, particularly those affecting the pumps or
the control system, should only be remedied by
Wilo's customer service or a specialist company.
Fault
Pump does not start
Pump does not shut down.
Installation and operating instructions Wilo-FLA
Cause
No mains voltage
Main switch "OFF"
Water level in break tank too low, i.e.
low-water level reached
(malfunction only occurs in test opera-
tion)
Low-water signal transmitter defective
(malfunction only occurs in test opera-
tion)
Electrodes incorrectly connected,
incorrectly set
(malfunction only occurs in test opera-
tion)
Check valve closed at pressure sensor/
switch
Switch-on pressure set too low
Switch-on/off pressures for pressure
switch are not coordinated
Motor protection triggered
(malfunction only occurs in test opera-
tion)
Contactor defective
Turn-to-turn fault in the motor
Intake pipe blocked or shut off
Nominal diameter of the inlet pipe too
small
Inlet pipe installed incorrectly
Air in the inlet
Impellers blocked
Non-return valve leaking
Non-return valve blocked
Gate valve in the system closed or not
sufficiently open
Flow rate too high
Check valve closed at pressure sensor
Switch-off pressure set too high
Pressure switch or cable defective
Incorrect direction of rotation of the
motors
NOTE!
The general safety instructions must be observed
during any maintenance or repair work. Also fol-
low the installation and operating instructions of
the pumps and the control device.
Remedies
Check the fuses, cables and connec-
tions.
Switch on the main switch.
Check the break tank's inlet valve/sup-
ply line.
Check and, if necessary, replace the
low-water signal transmitter.
Check the installation or setting and
correct it.
Check and open the check valve if nec-
essary.
Check the setting and correct it if nec-
essary.
Check the setting and correct it if nec-
essary.
Check set values against the pump or
motor data, measure current values and
correct setting if necessary. Check
motor for defects and replace if neces-
sary.
Check it and replace it if necessary.
Check, if necessary replace motor or
have repaired.
Check the inlet pipe and remove the
blockage or open the check valve if
necessary.
Check the inlet pipe and increase the
cross-section of the inlet pipe if neces-
sary.
Check the inlet pipe and change the
pipe routing if necessary.
Check and shut off the piping and vent
the pumps if necessary.
Check the pump and replace it or have it
repaired if necessary.
Check and replace the seal or non-
return valve if necessary.
Check and remove the blockage or
replace the non-return valve if neces-
sary.
Check and open the check valve com-
pletely if necessary.
Check the pump data and default values
and correct them if necessary.
Check and open the check valve if nec-
essary.
Check the setting and correct it if nec-
essary.
Check pressure switch or cable and
replace if necessary.
Check direction of rotation and correct
by changing over phases if necessary
English
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