GB
NM-NMD Rev23 - Operating Instructions
Page 11 / 64
6.5. Electrical connection
OFF
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.
ATTENTION: with motor power rating ≥ 5.5 kW
avoid direct starting. Provide a control panel
with star-delta starting or an other starting
device.
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. 12.4 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
device with curve D appropriate for the rated current
of the pump.
Single-phase NMM, NMDM, CM, are supplied with a
capacitor connected to the terminals and (for 220-240
V - 50 Hz) with an incorporated thermal protector.
ATTENTION: When the pump is fed by a
frequency converter, the minimum frequency
should not fall below 25Hz and in any case the
total head of the pump should never be lower
than 3 m.
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
OFF
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 par. 12.3 fig. 2) 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. 3).
When the liquid level on the suction side is above
the pump (inflow under positive suction head par.
12.3 fig. 1), fill the pump by opening the suction gate
valve slowly and completely, keeping the delivery gate
valve (and the air valve with the NMD pumps) 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
arrow on the pump casing, otherwise disconnect
electrical power and reverse the
connections of two phases.
Check that the pump works within its field of
performance, and that the absorbed current shown on
the name-plate is not exceeded.
Otherwise adjust the delivery gate valve or the setting
of any pressure switches.
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.
7.3. Switch off of the pump
ON
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”).
8. MAINTENANCE
Before any operations it's necessary to disconnect the
power supply.
If required ask to an electrician or to an expert
technician.
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
executed.
i
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.
i
During maintenance operations external
personnel is not allowed.
NM-NMD Rev23.indd 11
19/04/17 10:13
