8
SUBMERSIBLE MOTOR-DRIVEN PUMPS
– In single phase versions, plug the unit into the socket.
– For threephase versions (FIG. 7), check that the motor turns in a an-
ti-clockwise direction looking at the pump from the top, proceed as
follows: with the motor-driven pump not yet secured to the system,
connect the power cable to the terminal board and switch on briefly; the
pump shall start with a kick in an clockwise direction, seen from the top
of the pump. If the direction is wrong (anti-clockwise), invert two of the
three wires in the terminal board of the electrical panel.
FI
G. 9 shows the standard voltages shown on the plate with their respec
-
tive tolerances.
8.1. ADJUSTMENTS AND RECORDINGS
In pumps fitted with a float, adjust the length of the float cable with regards
to the minimum and maximum value of the water (see fig
1;2;3).
Check that the system automatisms do not require a number of start-ups
higher than the number shown in PART 12
9. USE AND STARTING
NEVER ALLOW THE MOTOR-DRIVEN PUMP TO OPERATE WITH-
OUT WATER. DOING SO CAN SERIOUSLY DAMAGE THE INTERNAL
COMPONENTS.
9.1. GENERAL WARNINGS
a) our motor-driven pumps cannot be used in swimming pools or similar
plants;
b) prolonged motor pump operation with the delivery pipe closed can
cause damage;
c) Avoid switching the motor pump on and off more than 50,000 times a
year. If operate the pump on and off more than 50,000 times per year,
the pump life may be shortened and there is a risk of premature failure.
Regarding the maximum number per hour, please refer also Chapter 8;
d) during power cuts, it is advisable to disconnect the power to the pum;
e) Select the pump so that it will operate close to the best efficiency point,
at least between minimum and maximum rated flow rate.
9.2.
VERSION WITH FLOAT
Plug into the power mains and/or turn on with the switch: the motor-driv
-
en pump starts working. Once the pump has sucked in enough water to
reach the minimum level (“OFF” level), regulated by the float, it will turn
off automatically.
The float’s working position is factory set so as to assure a minimum immer
-
sion level in the “OFF” position.
NB: If the liquid is overly contaminated, the operation of the magnetic-type
float (MS versions) may be compromised, meaning it needs to be cleaned
on a regular basis.
Moreover, do not use in liquids polluted with iron dust or magnetic material
as this would compromise the operation of the float.
VERSION WITHOUT FLOAT
Plug into the power mains and/or turn on with the switch: the motor-driven
pump starts working. Once the pump has sucked in enough water to reach
the minimum level, unplug from the power mains and/or turn off with the
switch.
9.3. STOPPING
a) Gradually interrupt water circulation in the delivery section to avoid
overpressure in the piping and pump caused by water hammering;
b) Cut off the power supply.
10. MAINTENANCE AND REPAIRS
To maintain the motor-driven pumps properly and ensure their long
service life, the filter and/or suction port must not be clogged and the
impeller must be clean.
During maintenance work on the motor-driv
-
en pumps, disconnect the power supply.
We recommend periodically
checking that the pump is working correctly; pay particular attention to
any abnormal noise or vibration.
The main and most common special maintenance operations are gen-
erally as follows:
− replacement of mechanical seals
− replacement of grommets
− replacement of bearings
− replacement of capacitors.
If the power cord needs changing on submersible pumps, this must be done
by an assistance centre only.
DAR MOTOR-DRIVEN PUMP (FIG. 4;5)
a) If the suction port is clogged, you must clean it, remembering to wear
work gloves at all times to avoid cutting your hands;
b) If the impeller is dirty, proceed as follows:
– wear work gloves to avoid cutting your hands;
– unscrew the six screws (1) keeping the pump casing closed (not the
nut as it is welded to the pump casing);
– remove the pump casing, pulling it off (2);
– remove the O-ring (3);
– take care not to damage the O-ring (3);
– make sure the space between the impeller and casing is also clean.
c) There is a small opening in the pump casing for air venting; keep it un
-
clogged and clean. It is normal for fluid to come out during priming.
10.1. TROUBLESHOOTING
DISPLAYED FAULT
CAUSE
SOLUTION
Float sticking
Check that the float
reaches the level ON
Thermal protection
activated
(single phase)
It reactivates
automatically
(single phase only)
EN
Incorrect electrical
connection
Check the terminal
board and the electrical
panel
THE PUMP DOES
NOT WORK
The motor turns
Automatic switch
triggered or fuses
blown
Reset the switch or
replace the fuses and
verify the cause
No electricity
Check the
electrical
supply meter
Plug not inserted
Check the
connection to the
power supply
THE PUMP DOES
NOT WORK
The motor turns
Decrease in the line
voltage
Wait for voltage to
return to normal
Suction filter / hole
blocked
Clean the
filter / hole
Foot valve
blocked
Clean the valve and
check its operation
Pump not
primed
Prime the pump
Check any delivery
non-return valves
Check the liquid level
Pressure
too low
Restrict the
delivery gate
THE PUMP WORKS
with a reduced flow
rate
System
undersized
Re-examine
the system
System dirty
Clean the piping,
valves, filters
Water level
too low
Switch off the pump or
immerse the foot valve
Incorrect rotational
direction
(threephase only)
Invert the two phases
Incorrect supply
voltage
Supply the pump with
the voltage indicated
on the ate
Leaks from piping
Check the joints
Pressure too high
Recheck the system