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NG,NGL,NGX Rev. 4 - Operating Instructions
GB
Tighten the pipes or union coupling to the extent sufficient
to ensure a tight seal.
Excessive torque may cause damage to the pump.
When the pipe or union coupling is mounted, keep the pump
casing connection blocked with a second wrench, making
sure the connection is not deformed by excessive tightening.
The pipe diameters must not be smaller than the pump con-
nections.
6.4.2. Suction pipe
For capacities over 4 m
3
/h use a suction pipe G 1 1/4 (DN 32).
The suction pipe must be perfectly airtight.
With a
pump located above the water level
(suction lift
operation, par. 12.3
fig. 1, fig. 3
) fit a foot valve with strainer
(which must always remain immersed) or a check valve on
the suction connection.
If operating with
flexible hoses
use a semi rigid suction hose, in
order to avoid the hose narrowing due to suction vacuum.
With the
liquid level on the suction side above the pump
(inflow under positive suction head, par. 12.3
fig. 2
) fit an
inlet gate valve.
Follow local specifications if increasing network pressure.
Install a strainer on the suction side of the pump to pre-
vent foreign particles from entering the pump.
6.4.3. Delivery pipe
Fit a gate valve in the delivery pipe to adjust delivery and
head.
Install a pressure gauge.
6.5 Electrical connection
Electrical connection must be carried out only by a
qualified electrician in accordance with local
regulations.
Follow all safety standards.
The unit must be properly earthed (grounded).
Connect the earthing (grounding) conductor to the terminal
with the
marking.
Compare the frequency and mains voltage with the name-
plate data and connect the supply conductors to the terminals
in accordance with the appropriate diagram inside the termi-
nal box cover.
ATTENTION: never allow washers or other metal
parts to fall into the internal cable opening between
the terminal box and stator.
If this occurs, dismantle
the motor to recover the object which has fallen inside.
If the terminal box is provided with an inlet gland, use a flexi-
ble power supply cord of the H07 RN-F type with section of
cable not less than (par. 12.5 TAB 1).
If the terminal box is provided with an inlet bushing, connect
the power supply cord through a conduit.
For use in swimming pools (not when persons are in the
pool), garden ponds and similar places, a
residual current
device
with IΔN not exceeding 30 mA must be installed in
the supply circuit.
Install a
device for disconnection from the mains
(switch)
with a contact separation of at least 3 mm in all poles.
With a three-phase motor install an overload protection devi-
ce with curve D appropriate for the rated current of the pump.
Single-phase NGM, NGXM, NGLM,
are supplied with a capa-
citor connected to the terminals and (for 220-240 V - 50 Hz)
with an incorporated thermal protector.
7 STARTUP AND OPERATION
7.1 Preliminary checks before start-up of the pump
Do not start-up the device in case of damaged parts.
7.2 First starting
ATTENTION: never run the pump dry.
Start the pump after fil-
ling it completely with liquid.
When the pump is located above the water level
(suction
lift operation, par. 12.3
fig. 1, fig. 3
) or with a positive suction
head which is too low (less than 1 m) to open the non-return
valve, fill the pump through the priming hole (par. 12.3
fig. 5
).
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 comple-
tely, 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 con-
nections 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 properly
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. 12.2
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. 12.2
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 con-
nection the filling operation must be repeated before
each start-up.
ATTENTION: avoid a prolonged operation with unprimed
pump, without water delivery from the completely ope-
ned outlet (t1,
par. 12.2
fig.1, max 22 min).
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 reduce 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 operation
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 temperature is
higher than 80 °C.
Wait until the water has cooled inside the pump before star-
ting 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 (cau-
sed by a lack of water inflow in the inlet pipe under positive
suction head, by a non-immersed suction pipe, by excessi-
ve suction lift or by air entering the suction pipe);
• against operation with closed connection ports.
See installation example par. 12.3
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 switch off
is performed by disconnecting the power supply by means
the expected disconnecting devices. (see paragraph "6.5
Electrical connection").
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OFF
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IST NG_NGX_NGL 02_2018_MXS 11_03con gall 19/01/18 08:10 Pagina 8
