ENGLISH
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10.2 Blanking flanges
For twin-head pumps, a blanking flange with a pump housing gasket is
available. If one pump requires service, the blanking flange is fitted to allow
the other pump to continue operating.
10.3 Lubricating the bearings
Carry out maintenance based on the type of bearing
indicated on the technical data plate. See tables at the
end of the booklet.
11.
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.
If the fault is repeated immediately this means
that the motor is short circuiting.
−
Check that the motor is live.
The pump supplies
insufficient flow.
−
The impeller is worn or blocked.
Change the impeller or remove the obstruction.
−
Check that the direction of rotation on three-
phase versions is correct.
Invert the connection of two supply wires.
The motor does not start
but makes noise.
−
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.
−
Capacitor short-circuiting or broken.
Change the capacitor.
The motor turns with
difficulty.
−
Check the supply voltage which may be
insufficient.
−
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 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.
−
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 motor rotation speed.
Consult the motor data plate.
−
Check the state of the bearings.
Change any worn bearings.
The pump vibrates and
operates noisily.
−
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.
−
Ensure that the mains voltage corresponds to
the voltage on the data plate.
Fig.4
