Fault
Cause
Remedy
2. The motor-protective circuit
breaker has tripped because the
motor is overloaded.
a)The pump is blocked by
impurities.
Clean the pump.
b) The pump is running above
rated duty point.
Set the duty point in accordance
with the data sheet.
c) The density or viscosity of the
liquid is higher than specified when
ordering.
If less flow is sufficient, reduce the
flow on the outlet side. Otherwise,
fit a more powerful motor.
d) The motor-protective circuit
breaker overload setting is
incorrect.
Check the setting of the motor-
protective circuit breaker and adjust
it, if necessary.
e)The motor runs on two phases.
Check the electrical connection.
Replace the fuse, if defective.
3. The pump makes too much noise.
The pump runs unevenly and
vibrates.
a) The inlet pressure is too low, that
is the pump cavitates.
Increase the liquid level on the inlet
side. Open the isolating valve in the
inlet pipe. Make sure that all the
conditions in section Pipes are
complied with.
b) There is air in the inlet pipe or
pump.
Vent the inlet pipe or the pump.
c) The counterpressure is lower
than specified.
Set the duty point in accordance
with the data sheet.
d) The pump draws in air due to
low liquid level.
Increase the liquid level on the inlet
side and keep it as constant as
possible.
e) The impeller is out of balance or
the impeller blades are clogged.
Clean and check the impeller.
f) The inner parts are worn.
Replace the defective parts.
g) The pump is stressed by the
pipes thus causing starting noise.
Mount the pump so that it is not
stressed. Support the pipes.
h) The bearings are defective.
Replace the bearings.
i) The motor fan is defective.
Replace the fan.
j) There are foreign bodies in the
pump.
Clean the pump.
k) Frequency converter operation.
See section Frequency converter
operation.
4. The pump, connections or
mechanical shaft seal are leaking.
a) The pump is stressed by the
pipes thus causing leaks in the
pump housing or at connections.
Mount the pump so that it is not
stressed. Support the pipes.
b) Pump housing gaskets and
gaskets at connections are
defective.
Replace the pump housing gaskets
or gaskets at connections.
c) The mechanical shaft seal is
dirty or stuck together.
Check and clean the mechanical
shaft seal.
d) The mechanical shaft seal is
defective.
Replace the mechanical shaft seal.
e) The shaft surface is defective.
Replace the shaft.
37
English (GB)
Summary of Contents for NB 80-200/222VAXEF1BESBQQEWX2
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