DISPLAYED FAULT
CAUSE
System
undersized
System dirty
Water level
too low
Incorrect rotational
direction
THE PUMP WORKS
(threephase only)
with a reduced flow
rate
Incorrect supply
voltage
Leaks from piping
Pressure too high
Supply voltage out-
side motor's accepted
range
Inadequate thermal
cutout setting
Motor overload due to
dense and/or viscous
liquid
PUMP STOPS
AFTER
RUNNING FOR
SHORT TIME
as a result of
Pump delivers liquid
thermal
at higher rate than
overload
max. flow rate on
protection tripping
rating plate
Panel exposed to
sun or other sources
of heat
Foreign matter brakes
impeller rotation
Motor bearings worn
THE PUMP STOPS
Liquid temperature
too high
AFTER WORKING
FOR BRIEF
PERIODS
Thermal protection
intervention
Internal fault
SOLUTION
System
THE PUMP STOPS
undersized
Clean the piping, val-
FOR BRIEF PERIODS
ves, filters
Switch off the pump
or immerse the foot
valve
Invert the two phases
Supply the pump with
the voltage indicated
on the ate
Check the joints
Recheck the system
Check whether there
are excessive drops in
voltage due to under-
sized line or cables
Adjust setting to
motor's rated current
(see rating plate)
does not manage to
complete even one
- Reduce flow rate,
to turn the odd half
throttling the delivery
turn before the cir-
line or replace motor
cuit breaker trips or
with more powerful
one
- Check actual power
absorbed by the
pump based on liquid
circuit breaker trips
pumped
Reduce flow rate by
throttling delivery line
few turns in oppo-
site direction when
Protect panel from
sun or
sources of heat.
- Disassemble and
clean pump
- Call our nearest
Servicing De-
partment to do
the job
- Replace bearings
- In this case, motor
Pump vibrates and is
is noisy, too
The temperature
exceeds the
technical limits of the
pump
Contact the nearest
retailer
DISPLAYED FAULT
CAUSE
The difference
AFTER WORKING
between
maximum and mi-
nimum pressure is
Pressure
minimal
applications
THE PUMP DOES
NOT STOP
Maximum
Pressure applica-
pressure too high
tions
Flow rate too high
Cavitation
Irregular piping
THE PUMP
VIBRATES
Noisy bearing
Or is too noisy du-
ring operation
Foreign bodies sliding
along the motor fan
Incorrect priming
When the switch
Motor
closes, the pump
short-circuited
turn or struggles
Short-circuit due to
incorrect connection
fuses blow
Leakage current owing
Residual current
to damaged insulation
of motor, cables or
as soon as switch
other electric com-
closes
ponents
Pump performs a
Foot valve leaking
Suction pipe leaking
stopping
Motor bearings worn
Foreign matter betwe-
en fixed and rotating
parts
unusually noisy
Pump operation
affected by cavitation
SOLUTION
Increase the differen-
ce between the two
pressures
Set maximum
pressure at a
lower value
EN
Reduce the flow rate
Contact the nearest
retailer
Fix in a better way
Contact the nearest
retailer
Remove the foreign
bodies
Bleed the pump and/
or fill it again
Check and replace
Check and reconnect
correctly
Check and replace
electric component
with ground fault
Check, clean or replace
Check and repair
Replace bearings
- Disassemble and
clean pump
- Call our nearest Ser-
vicing Department to
do the job
Reduce flow rate by
throttling delivery line.
If cavitation persists,
check:
- Suction height
- Pressure loss along
suction line (diame-
ter of pipe, elbows
etc.)
- Liquid temperature
- Delivery line
backpressure
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