DAB CP, Instruction For Installation And Maintenance

Page: 21 / 80

ENGLISH
15
Fault Check (possible cause) Remedy
− Ensure that the mains voltage
corresponds to the voltage on the
data plate.
− Check that the connections have
been made correctly.
Correct any errors.
− Check that all the phases are
present on the terminal board.
If not, restore the missing phase.
− The shaft is blocked. Look for
possible obstructions in the pump
or motor.
Remove any obstructions.
The motor does not start but makes
noise.
− Capacitor short-circuiting or
broken.
Change the capacitor.
− Check the supply voltage which
may be insufficient.
− Check whether any moving parts
are scraping against fixed parts.
Eliminate the cause of the scraping.
The motor turns with difficulty.
− Check the state of the bearings.
Change any worn bearings.
− Check that all the phases are
present on the terminal board (on
three-phase models).
If not, restore the missing phase.
− Look for possible open or dirty
contacts in the protection.
Change or clean the component
concerned.
The (external) motor protection trips
immediately after starting .
− 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.
− 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 motor rotation speed.
Consult the motor data plate.
The motor protection trips too
frequently.
− Check the state of the bearings.
Change any worn bearings.
− Check that the pump and/or the
pipes are firmly anchored.
Fasten any loose parts.
− There is cavitation in the pump.
Increase the system pressure,
keeping within the allowed limits.
− The pump is running above its
plate characteristics.
Reduce the flow rate.
The pump vibrates and operates
noisily.
− Ensure that the mains voltage
corresponds to the voltage on the
data plate.
− Check that the fluid density or
viscosity is not too high.
Analyse the fluid to be pumped.
− Check whether any moving parts
are scraping against fixed parts.
Eliminate the cause of the scraping.
− The feeding voltage is not the
same as the voltage on the data
plate.
Feed the motor with the correct
voltage.
The absorbed current is too high.
− The pump is running above its
plate characteristics.
Reduce the flow rate.