Delivery Pipe; Electrical Connection; Operation With Frequency Converter; Startup And Operation - Calpeda Nmx Bedienungsanleitung

always remain immersed 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

EN
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
protect the pump from water hammering.
With a variable frequency drive, the check valve must
be installed before the pressure transducer.

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
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
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 NMXM, 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.
Page 12 / 80
marking.
other starting

6.6. Operation with frequency converter

Adjust the frequency converter so that the limiting
values of min. 25 Hz and max. nominal frequency (50
or 60 Hz).
It is necessary to install a dv/dt filter at the output of
converter if the power cable is longer than 2 meters.
It is necessary to install a dv/dt filter or an insulated
bearing if both of the following conditions are met:
- frequency converter has a PWM frequency higher
than 8 kHz;
- nominal power >7,5 kW if 2-pole motor or nominal
power >4 kW if 4-pole motor.
Furthermore, it is necessary to install a dv/dt filter or an
insulated bearing in all the cases where the drive has a
working frequency f <4/5f
l
where T is defined in 24 hours and f
motor frequency (i.e. higher than 8 hours per day).
In any condition the dv/dt limit curve prescribed in
the technical appendix of Calpeda catalogue must
not be exceeded furthermore, the minimum working
frequency must guarantee fluid pumping and comply
the manufacturer's prescriptions.
Voltage peaks or increased acoustic noise can be
abated by installing a dv/dt filter between the frequency
converter and the motor.

7. STARTUP AND OPERATION

7.1. Preliminary checks before start-up of the
pump
The pumps may contain small quantities of
residual water from testing.
When pumping drinking water, the pump must
be flushed thoroughly with clean water before
startup in order to remove any foreign matters,
such as preservatives, test liquid, or grease.
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. 12.1 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. 12.1 fig. 3).
When the liquid level on the suction side is above
the pump (inflow under positive suction head par.
12.1 fig. 1), 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 arrow
NMX Rev100000286_01 - Operating Instructions
for a time higher than 1/3T
n
is the nominal
n