Problems, Causes And Remedies - Wilo -NL 32-125 Einbau- Und Betriebsanleitung

10. Problems, causes and remedies

CAUTION! Only appropriately trained personnel
must undertake troubleshooting.
Problems
Output too low
Pump does not prime or only intermitt-
ently
Pump leaks
Temperature of the pump increases
Noisy pump
The motor contactor trips
WILO AG 09/2007
Causes
Back pressure too high
Pump or pipework, not completely filled Vent and fill the pump as well as the
Suction lift too high or positive suction
head too low
Impeller sealing gap too large
Wrong direction of rotation
Pump casing, shaft seal, foot valve or
suction line leaks
Suction lift too high or positive suction
head too low.
Loose or jammed parts in the pump
Casing bolts not correctly tightened
Mechanical seal leaks
Pump or pipework not completely filled
Suction lift too high or positive suction
head too low
Pump is run against closed valve
Pump or pipework not completely filled
Suction lift too high or positive suction
head too low
Pump is not properly levelled or is dis-
torted
Foreign material in the pump
Pump is not properly levelled or is dis-
torted
Earth fault
Operating conditions outside of perfor-
mance range of pump
Loose or jammed parts in the pump
Remedies
Check the plant for contamination.
Regulate anew the operating point
suction or inflow line
Check the liquid level; open the shut-off
valves on the suction side. Clean the fil-
ters
Replace worn parts
Change the motor connection
Replace the casing seal. Check the shaft
seal. Check the flange connections
Check the liquid level; open the shut-off
valves on the suction side. Clean the fil-
ters on the suction side
Open and clean the pump
Check the tightening torque of the
casing boltse
Check the seal surfaces and rubber
material of the mechanical seal. In case
of damages exchange mechanical seal
Vent and fill the pump as well as the
suction line or inflow line
Check the liquid level; open the shut-off
valves on the suction side. Clean the fil-
ters on the suction side
Open the shut-off valve on discharge
side
Purge of air the pump and the pipework
Check the liquid level; open the shut-off
valves on the suction side. Clean the fil-
ters on the suction side
Check the pump levelling and alignment
Dismantle and clean the pump
Check the pump levelling and alignment
Check the earth connection. Check the
potential causes such as damaged
wirings or cables, leakages on electrical
parts
Refer to pump operating conditions sta-
ted in technical data
Open and clean the pump
English
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