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NG,NGL,NGX Rev. 7 - Operating Instructions
EN
When the liquid level on the suction side is above
the pump
(inflow under positive suction head,
fig. 2
), fill
the pump by opening the suction gate valve slowly and
completely, keeping the delivery gate valve open to
release the air.
Before starting, check that the shaft turns by hand. For
this purpose use the screwdriver notch on the shaft end
on the ventilation side.
When starting, with a three-phase motor, check
that
the direction of rotation
is as shown by the arrows on
the lantern bracket: clockwise when viewing the motor
from the fan end.
Otherwise, disconnect electrical power and reverse the
connections of two phases.
7.3. Self-priming
(Capability to clear the air in the suction pipe when
starting with the
pump located above the water level
).
Conditions for self-priming:
• suction pipe with connections perfectly airtight and pro-
perly immersed in the water to be lifted;
• allow 0,5 m (1 m for NG) minimum of straight vertical
pipe above the discharge port (par. 12.1
fig. 1
);
•
pump casing completely filled with clean cold
water berfore starting.
The pump is not self-priming with liquids containing
oil, alcohol or foaming substances.
The check valve (par. 12.1
fig. 1
) prevents reverse
siphoning through the pump when the pump is stopped
and retains water in the pump for the next start.
Without a foot valve or a check valve on the suction
connection
the filling operation must be repeated
before each start-up.
ATTENTION: avoid a prolonged operation with
unprimed pump, without water delivery from the
completely opened outlet.
If necessary, repeat the priming operation after the pump
has been first emptied and then completely filled with
clean cold water.
7.4. Gate valve regulation
With the gate valve completely open or with an outlet
pressure lower than the minimum pressure shown
on the name-plate, the pump may be noisy. To redu-
ce noise regulate the delivery gate valve.
7.5. Abnormal operation
Never run the pump for more than five
minutes with a closed gate valve.
Prolonged operation without a change of water in the
pump causes dangerous increases of temperature and
pressure.
Prolunged operation with a closed delivery port causes
breakage or damage to parts of the pump (see
section
6.2.
).
When the water is overheated due to prolonged opera-
tion with a closed port, stop the pump before opening the
gate valve.
Do not touch the fluid when its temperature is
higher than 60 °C.
Do not touch the pump when the surface temperatu-
re is higher than 80 °C.
Wait until the water has cooled inside the pump before
starting again or opening the draining and filling plugs.
7.6. Automatic regulator IDROMAT
(can be supplied on request)
For automatic control of starting/stopping of the pump
when utilization points are opened/closed.
For protection of the pump:
• against dry running;
• against the risk of operation without water at the inlet
(caused by a lack of water inflow in the inlet pipe under
positive suction head, by a non-immersed suction pipe,
by excessive suction lift or by air entering the suction
pipe);
• against operation with closed connection ports.
See installation example par. 12.1
fig. 2
.
7.7 Switch off of the pump
The appliance must be switch off every time there
are faults. (see troubleshooting).
The product is designed for a continuous duty, the swit-
ch off is performed by disconnecting the power supply by
means the expected disconnecting devices. (see para-
graph "6.5 Electrical connection").
8 MAINTENANCE
Before any operations it's necessary to disconnect the
power supply.
If required ask to an electrician or to an expert techni-
cian.
Every maintenance operations, cleaning or
reparation executed with the electrical system
under voltage, it could cause serious injuries to
people.
If the supply cord is damaged, it must be replaced
by the manufacturer, its service agent or similarly
qualified persons in order to avoid a hazard.
In case of extraordinary maintenance, or maintenance
operations that require part-removing, the operator must
be a qualified technician able to read schemes and
drawings.
It is suggest to register all maintenance operation execu-
ted.
During maintenance keep particular attention in
order to avoid the introduction of small external
parts, that could compromise the device safety.
It is forbidden to execute any operations with the
direct use of hands. Use water-resistant, anti-cut
gloves to disassemble and clean.
During maintenance operations external
personnel is not allowed.
Maintenance operations that are not described in this
manual must be made only by special personnel authori-
zed by Calpeda S.p.A.
For further technical information regarding the use or the
maintenance of the device, contact Calpeda S.p.A.
8.1 Routine maintenance
Before every maintenance operations disconnect the
power supply and make sure that the device could
not accidentally operate.
When the pump remains inactive it must be emptied
completely if there is a risk of freezing
(
fig. 6
).
Before restarting the unit, check that the shaft is not jam-
med and fill the pump casing completely with liquid.
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IST NG_NGX_NGL REV7 05_2021.qxp_MXS 11_03con gall 24/05/21 09:58 Pagina 10
