MAGSON centrifugal pumps
29
Issue 2018-05
Troubleshooting
Malfunction
Cause
Elimination
The delivery rate is too
high.
Pump losses are less
significant than
presumed.
Reduce the flow rate of the
discharge line.
Reduce the impeller diameter.
Use a frequency converter to
adjust the motor speed.
Unusual mechanical
running noise.
Damaged bearing of the
motor.
Take the motor off the pump
and check the motor bearings.
Foreign particle in the
pump head.
Open the pump head to check
it.
The pump head bearing
overheats when running
dry or hot.
Open the pump head to check
it. Replace the sleeve bearing,
if necessary.
Leakage between pump
and motor.
The pump housing is
damaged.
The pump is damaged
because of solids, dry-
running or
overheating*.
Make an expert dismantle the
pump and eliminate the fault.
Table 4: Troubleshooting
*) Detailed information on overheating and dry-running
„Overheating“
means the excessive warming of the fluid resulting from a closed
discharge and/or suction line. As the fluid cannot leave the pump, there is no exchange of
fluid. The fluid remains in the pump where it permanently circulates and heats up. This
excessive warming may cause considerable damage to the pump and its components.
To avoid an increase in temperature, the minimum flow rate must not fall
below 5% of the maximum delivery rate!
If a pump is
„running dry“
, there is either air in the pump chamber or the pump is not
filled up with fluid. Being neither cooled nor lubricated, the sleeve bearings will overheat.
As a consequence, the plastic material of the pump will also overheat resulting in a leaky
rear casing out of which fluid will pass.
Do not hesitate to ask us for further information on dry running and
overheating. We will be glad to help you.
