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9.
Noise
a) Cavitation occurs in the pump.
Increase the inlet pressure or reduce the liquid
temperature.
b) Pump does not rotate freely (frictional re-
sistance) because of incorrect pump shaft
position.
Adjust the shaft and check the shaft seal.
c) Frequency converter operation.
See the section on frequency converter opera-
tion in the installation and operating instruc-
tions.
d) Resonance in the installation.
Consider vibration dampening. See the sec-
tion on foundation in the installation and oper-
ating instructions.
e) Foreign bodies in the pump.
Clean the pump and inspect for damage.
10. Pump runs constantly
(applies only to pumps
with automatic start/
stop).
a) The stop pressure has been set too high.
Reduce the selected stop pressure.
b) Leakage in the discharge pipe.
Repair the leakage.
c) The direction of rotation of the pump is in-
correct.
Change the direction of rotation.
d) Pipes, valves or strainer clogged by impu-
rities.
Clean the pipes, valves or strainer.
e) Pump controller, if fitted, is defective.
Replace the pump controller.
11. Period of operation is too
long (applies only to
pumps with automatic
start/stop).
a) The stop pressure has been set too high.
Reduce the selected stop pressure.
b) Pipes, valves or strainer clogged by impu-
rities.
Clean the pipes, valves or strainer.
c) Pump partly blocked.
Clean the pump and inspect for damage.
d) Leakage in the discharge pipe.
Repair the leakage.
Fault
Cause
Remedy
