Electrical Requirements - Xylem LOWARA e-MPA Manual De Instalación, Funcionamento Y Mantenimiento

en - Original instructions
to prevent transmission of pump vibrations
to the pipes and vice versa.

Use wide bends, avoid using elbows which
cause excessive flow resistance.

The suction piping is perfectly sealed and
air- tight.

If the pump is used in an open circuit, then
the diameter of the suction pipe is suited to
the installation conditions. The suction pipe
must not be smaller than the diameter of
the suction port.

If the suction piping must be larger than the
suction side of the pump, then an eccentric
pipe reducer is installed.

If the pump is placed above liquid level, a
foot valve is installed at the end of the
suction piping.

The foot valve is fully immersed into the
liquid so that air cannot enter through the
suction vortex, when the liquid is at the
minimum level and the pump is installed
above the liquid source.

Appropriately sized on-off valves are
installed on the suction piping and on the
delivery piping (downstream to the check
valve) for regulation of the pump capacity,
for pump inspection, and for maintenance.

Appropriately sized on-off valve is installed
on the delivery piping (downstream to the
check valve) for regulation of the pump
capacity, for pump inspection, and for
maintenance.

In order to prevent back flow into the pump
when pump is turned off a check valve is
installed on the delivery piping.
WARNING:
Do not use the on-off valve on the
discharge side in the closed position in
order to throttle the pump for more than
a few seconds. If the pump must
operate with the discharge side closed
for more than a few seconds, a bypass
circuit must be installed to prevent
overheating of the liquid inside the
pump.
For illustrations that show the piping
requirements, see Figure 11
4.2

Electrical requirements


The local regulations in force overrule
these specified requirements.

In the case of fire fighting systems
(hydrants or sprinklers), check the local
regulations in force.
Electrical connection checklist
Check that the following requirements are met:

The electrical leads are protected from high
temperature, vibrations, and collisions.

The power supply line is provided with:
–
A short-circuit protection device
1
Fuses aM (motor starting), or magneto-thermal switch with
curve C and Icn ≥ 4,5 kA or other equivalent device.
2
Overload thermal relay with trip class 10A + fuses aM
20
and Figure 12.
–
A mains isolator switch with a contact
gap of at least 3 mm.
The electrical control panel checklist
NOTICE:
The control panel must match the ratings of the
electric pump. Improper combinations could fail to
guarantee the protection of the motor.
Check that the following requirements are met:

The control panel must protect the motor
against overload and short-circuit.

Install the correct overload protection
(thermal relay or motor protector).
Pump Type Protection
– Thermal protection (must
Three
phase be supplied by the
electric installer)
– Short circuit protection
1
pump
(must be supplied by the
installer)

The control panel must be equipped with a
dry-running protection system to which a
pressure switch, float switch, probes, or
other suitable device is connected.

The following devices are recommended
for use on the suction side of the pump:
–
When the liquid is pumped from a
water system, use a pressure switch.
–
When the liquid is pumped from a
storage tank or reservoir, use a float
switch or probes.

When thermal relays are used, relays that
are sensitive to phase failure are
recommended.
The motor checklist
WARNING:

Read the operating instructions in
order to ensure whether a
protection device is provided if
another motor other than the
standard is used.

If the motor is equipped with
automatic thermal protectors, be
aware of the risk of unexpected
starts in connection to overload.
Do not use such motors for fire-
fighting applications.
NOTICE:
 Only use dynamically balanced motors with a
half-sized key in the shaft extension (IEC
60034-14) and with normal vibration rate (N).
 The mains voltage and frequency must agree
with the specifications on the data plate.
In general, motors can operate under the
following mains voltage tolerances:
(motor starting) or motor protection magneto-thermal switch
with starting class 10A.
2