PROBLEM
1) The engine
does not start
2) Pump blocked
3)The pump func-
tions but no wa-
ter comes out
4) Insufficient flow
5) Noise and vi-
brations from
the pump
6) Leakage from
the mechanical
seal
PROBABLE CAUSES
1a) Unsuitable power supply
1b) Incorrect electrical connections
1c) Engine overload protective device
cuts in.
1d) Blown or defective fuses
1e) Shaft blocked
1f) If the above causes have already been
checked, the engine may be
malfunctioning
2a) Prolonged periods of inactivity with
formation of rust inside the pump
2b) Presence of solid bodies in the pump
rotor
2c) Bearings blocked
3a) Presence of air inside the pump or
suction tube
3b) Possible infiltration of air from suction
tube connections, drain plugs or filling
of pump or from the gaskets of the
suction pipe
3c) Foot valve blocked or suction pipe
not fully immersed in liquid
3d) Suction filter blocked
4a) Pipes and accessories with diameter
too small causing excessive loss of
head
4b) Presence of deposits or solid bodies in
the internal passages of the rotor
4c) Rotor deteriorated
4d) Worn rotor and pump case
4e) Gases dissolved in the water
4f) Excessive viscosity of the liquid
pumped (if other than water)
4g) Incorrect direction of rotation
4h) Suction head excessive in relation to
the suction capacity of pump
4i) Suction pipe too long
5a) Rotating part unbalanced
5b) Worn bearings
5c) Pump and pipes not firmly attached
5d) Flow too strong for the diameter of the
delivery pipe
5e) Functioning in cavitation
5f) Unbalanced power supply
6a) The mechanical seal has functioned
when dry or has stuck
6b) Mechanical seal scored by presence
of abrasive parts in the liquid pumped
6c) Mechanical seal unsuitable for the
type of application
6d) Slight initial drip during filling or on
first start-up
13. Troubleshooting
WARNING: Turn off the power supply before performing any operations.
Do not allow the pump or engine to run when dry even for a short period
Strictly follow the user instructions and if necessary contact an authorised service centre
POSSIBLE REMEDIES
1a) Check that the mains frequency and voltage correspond to the electrical
characteristics shown on the indicator plate
1b) Connect the power supply cable to the terminal board correctly. Check that the
thermal overload protection is set correctly (see data on the engine indicator
plate) and make sure that the fuseboard upline of the engine has been properly
connected
1c) Check the power supply and make sure that the pump shaft is turning freely.
Check that the thermal overload protection has been set correctly (see engine
indicator plate)
1d) Replace the fuses, check the electric power supply and points a) and c)
1e) Remove the cause of blockage as indicated in the “Blocked pump” instruction booklet
1f) Repair or replace the engine by applying to an authorised service centre
2a) The electric pump and small size motor-cylinder blocks can be unblocked by
using a screw driver to turn the relevant notch on the back of the shaft. For
bigger units rotation may be started directly from the pump shaft or from the joint
(remember to turn off the electricity supply first ) or contact an authorised service
centre
2b) If possible, dismantle the pump casing and remove any solid foreign bodies
inside the rotor, if necessary contact an authorised service centre
2c) If the bearings are damaged replace them or if necessary contact an authorised
service centre
3a) Release the air from the pump using the pump plugs and/or using the delivery
control valve .Repeat the filling operations until all air has been expelled
3b) Check which part is not tight and seal the connection adequately
3c) Clean or replace the bottom valve and use a suction pipe suitable for the
application
3d) Clean the filter, if necessary, replace it . See point 2b) also.
4a) Use pipes and accessories suitable for the specific application
4b) Clean the rotor and install a suction filter to prevent other foreign bodies from
entering
4c) Replace the rotor, if necessary, contact an authorised service centre
4d) Replace the rotor and the pump casing
4e) Perform the opening and closing manoeuvres through the feeder gate to
eliminate the gas inside the pump casing .If the problem persists, contact an
authorised service centre
4f) The pump is unsuitable
4g) Invert the electrical connections on the terminal board or control panel
4h) Try to close the feeder gate partially and/or reduce the difference in level of the
pump and the liquid being aspirated
4i) Bring the pump closer to the suction tank so as to use a shorter pipe. If necessary
use a pipe of a wider diameter
5a) Check that no solid bodies are obstructing the rotor
5b) Replace the bearings
5c) Anchor the delivery and suction piping as needed
5d) Use bigger diameters or reduce the pump flow
5e) Reduce the flow by adjusting the feeder gate and/or using pipes with a bigger
internal diameter. See point 4h) too
5f) Check that the mains voltage is right
In cases 6a), 6b) and 6c), replace the seal, if necessary contact an authorised
service centre
6a) Make sure that the pump casing (and the suction pipe if the pump is not self-
priming) are full of liquid and that all the air has been expelled. See point 5 e) too.
6b) Install a suction filter and use a seal suited to the characteristics of the liquid
being pumped.
6c) Choose a seal with characteristics suitable for the specific application
6d) Wait for the seal to adjust to the rotation of the shaft. If the problem persists, see
points 6a), 6b) or 6c) or contact an authorised service centre .
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