ENGLISH
20
10. TROUBLESHOOTING
Fault
Check (possible cause)
Remedy
The motor does not start and makes
no noise.
−
Check the protection fuses.
If they are burnt-out, change them.
−
Check the electric connections.
Correct any errors.
−
Check that the motor is live.
−
Motor protector cut-off the motor,
for the single-phased motors, due
to over heating of tag windings.
Wait for automatic reset of the motor
protector once the temperature has
fallen below the maximum limit.
The motor does not start but makes
noise.
−
Check that supply voltage
correspond with voltage on the
pump label.
−
Check the electrical connections.
Correct any errors.
−
Check that all the phases are
present.
Restore the missing phase.
−
Check for obstructions in the
pump or motor.
Remove any obstructions.
The motor turns with difficulty.
−
Verify that supply voltage is at an
acceptable valve.
−
Check whether any moving parts
are scraping against fixed parts.
Eliminate the cause of the scraping.
−
Check the state of the bearings.
Change any worn bearings.
The (external) motor protection trips
immediately after starting.
−
Check that all the phases are
present.
Restore the missing phase.
−
Look for possible open or dirty
contacts in the protection.
Change or clean the component
concerned.
−
Look for possible faulty insulation
of the motor, checking the phase
resistance and insulation to earth.
Change the motor casing with the
stator or reset any cables
discharging to earth.
The motor protection trips too
frequently.
−
Ensure that the environment
temperature is not too high.
Provide suitable ventilation in the
environment where the pump is
installed.
−
Check the calibration of the
protection.
Calibrate at a current value suitable
for the motor absorption at full load.
−
Check the state of the bearings.
Change any worn bearings.
−
Check the motor rotation speed.
The pump does not deliver.
−
Check priming.
−
On three-phase motors, check
that the direction of rotation is
correct.
Invert the connection of two supply
wires.
−
Difference in suction level too
high.
−
The diameter of the intake pipe is
insufficient or the horizontal
stretch is too long.
Replace the intake pipe with one
with a larger diameter.
−
Foot valve or intake pipe blocked.
Clean the foot valve and the intake
pipe.
The pump does not prime.
−
The intake pipe or the foot valve
is taking in air.
Check the suction pipe, repeat the
priming operations.
−
Check the slope of the suction
pipe.
Correct the inclination of the intake
pipe.
The pump supplies insufficient flow.
−
Foot valve or impeller blocked.
Remove clog. Replace the impeller
if weared down.
−
The diameter of the intake pipe is
insufficient.
Replace the pipe with one with a
larger diameter.
−
Check that the direction of
rotation is correct.
Invert the connection of two supply
wires.
