6.4.2. Suction pipe
The suction pipe must be perfectly airtight and be led
upwards in order to avoid air pockets.
If operating with
flexible hoses
, use a reinforced spi-
ral suction hose in order to avoid hose narrowing due
to a suction vacuum.
With a
pump located above the water level
(suc-
tion lift operation), fit a
foot valve
or a
check valve
on the suction connection.
With
a pump located below water level
(inflow
under positive suction head) install a gate valve.
6.4.3. Delivery pipe
Fit a gate valve in the delivery pipe to adjust delivery,
head, and absorbed power.
Install a pressure gauge.
With a geodetic head of over 15 m fit a check valve
between the pump and the gate valve in order to pro-
tect the pump from water hammering.
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 terminal 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 flexible power supply cord of the H07 RN-F type
with section of cable not less than (par. 12.3 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
resi-
dual current device
with I
Δ
N 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 protec-
tion with curve D device appropriate for the rated cur-
rent of the pump.
Single-phase NMPM,
are supplied with a capacitor
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 filling it completely with liquid.
When the pump is located above the water level
(suction lift operation) fill the pump with water up to
suction pipe level through the opening on the strainer
after removing the cover
(fig. 2).
ATTENTION: for transportation the cover is tem-
porarily closed with hexagon nuts.
Replace them with the hand knobs (15.12) located
inside the filter.
When operating with the pump below water level
(inflow under positive suction head), fill the pump by
opening the suction gate valve slowly and comple-
tely, keeping the delivery gate valve open to release
the air.
With a three-phase motor check that the direction
of rotation
is as shown by the arrow on the pump
casing, otherwise, disconnect electrical power and
reverse the connections of two phases.
With a suction lift operation it may be necessary to
wait a few minutes for the pump to prime.
Check that the pump works within its field of perfor-
mance, and that the absorbed current shown on the
name-plate is not exceeded.
Otherwise adjust the delivery gate valve.
7.3 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 devi-
ces. (see paragraph "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.
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NMP Rev. 18 - Operating Instructions
Pagina 11 / 64
IST NMP Rev18 10_2022.qxp_MXS 11_03con gall 21/09/22 12:31 Pagina 11