DAB KDN Series, Instruction For Installation And Maintenance

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ENGLISH
32
14. TROUBLESHOOTING
FAULT CHECK (possible cause) REMEDY
1. The motor does not
start and makes no
noise.
A. Check the protection fuses.
B. Check the electric connections.
C. Check that the motor is live A. If they are burnt-out, change them.

If the fault is repeated immediately this means
that the motor is short circuiting..
2. The motor does not
start but makes noise.
A. Ensure that the mains voltage
corresponds to the voltage on the data
plate.
B. Check that the connections have been
made correctly.
C. Check that all the phases are present on
the terminal board.
D. The shaft is blocked. Look for possible
obstructions in the pump or motor.
B. Correct any errors.
C. If not, restore the missing phase.
D. Remove the obstruction.
3. The motor turns with
difficulty.
A. Check the supply voltage which may be
insufficient.
B. Check whether any moving parts are
scraping against fixed parts.
C. Check the state of the bearings.
B.
Eliminate the cause of the scraping.
C. Change any worn bearings.
4. The (external) motor
protection trips
immediately after
starting.
A. Check that all the phases are present on
the terminal board.
B. Look for possible open or dirty contacts
in the protection.
C. Look for possible faulty insulation of the
motor, checking the phase resistance and
insulation to earth.
D. The pump is functioning above the work
point for which it was intended.
E. The protection tripping values are wrong.
F. The viscosity or density of the pumped
fluid are different from those used in the
design phase.
A. If not, restore the missing phase.
B. Change or clean the component concerned.
C. Look for possible faulty insulation of the
motor, checking the phase resistance and
insulation to earth.
D. Set the work point to suit the pump
characteristics.
E. Check the set values on the motor protector:
alter them or change the component if
necessary.
F. Reduce the flow rate with a shutter on the
delivery side or install a larger motor.
5. The motor protection
trips too frequently.
A. Ensure that the environment temperature
is not too high.
B. Check the calibration of the protection.
C. Check the state of the bearings.
D. Check the motor rotation speed.
A. Provide suitable ventilation in the environment
where the pump is installed.
B. Calibrate at a current value suitable for the
motor absorption at full load.
C. Change any worn bearings.
6. The pump does not
deliver.
A. The pump has not been correctly primed.
B. Check that the direction of rotation of the
three-phase motors is correct.
C. Difference in suction level too high.
D. The diameter of the intake pipe is
insufficient or the length is too long.
E. Foot valve blocked.
A. Fill the pump and the intake pipe with water.
Prime the pump.
B. Invert the connection of two supply wires.
C. See point 8 of the instructions on ”Installation”.
D. Replace the intake pipe with one with a larger
diameter.
E. Clean the foot valve.
7. The pump does not
prime.
A. The intake pipe or the foot valve is taking
in air.
B. The downward slope of the intake pipe
favours the formation of air pockets.
A. Eliminate the phenomenon, checking the intake
pipe accurately, and prime again.
B. Correct the inclination of the intake pipe.
8. The pump supplies
insufficient flow.
A. Blocked foot valve.
B. The impeller is worn or blocked.
C. The diameter of the intake pipe is
insufficient.
D. Check that the direction of rotation is
correct..
A. Clean the foot valve.
B. Change the impeller or remove the obstruction.
C. Replace the pipe with one with a larger
diameter.
D. Invert the connection of two supply wires.
9. Invert the connection
of two supply wires.
A. Intake pressure too low.
B. Intake pipe or pump partly blocked by
impurities.
B. Clean the intake pipe and the pump.