AU
8
5.4 Electrical
connection:
The electrical connection must be carried out by a
specialist electrician. Applicable regulations must be
complied with.
Check the mains voltage available and the factory plate, and
choose the appropriate connection.
The technical connection conditions and the conditions
of the local energy supply company must be observed
when carrying out the connections.
We strongly recommend the use of a safety circuit
breaker for the motor and a thermistor associated to a
trigger device.
These instructions apply to asynchronous three-phase
standard electric motors with a squirrel cage both in
horizontal and vertical execution, in IP-23, IP-54 and IP-55
protection grades, with frame sizes of between 56L and
355S, both inclusive, with voltages of 200 to 500 V
between phases.
Before starting up the pump, it must be earthed or the
base frame must be connected to an effective earthed
point of the installation.
5.4.1 Motor
connection
Whilst connecting the cables, ensure it is not possible
for voltage to appear.
Check that the earth connection is in line with local
regulations.
The coupling may produce a source of ignition or high
temperature in the event of incorrect operation. For
this reason, the motor must be classified with at least the
same type of zone and temperature as the pump. It is
necessary to follow the instructions in the coupling manual
which is included with the pump.
Connection in single speed motors
Direct start-up:
In direct start-up the motor can be used in two different
connections:
The voltage and the connection, e.g. 400 VY, 240 VD is
stamped on the motor plate. This means that the motor can
connect at 400 volts in star connection (Y) or at 240 volts in
delta connection (D).
Star connection
Delta connection
Star-delta start-up:
In star-delta start-up, the line voltage must coincide with the
voltage shown on the motor for delta start up (D). The six
terminals indicated in the following diagram will be connected:
Connection to the star-delta contactor
5.4.2
Time relay adjustment
In the star-delta start-up of three-phase motors, it is necessary
to ensure that the passage from star to delta takes place
quickly. Prolonged time will cause damage to the pump.
Time relay adjustment in the star-delta connection:
Motor power
Time adjustment -Y
≤
30 kW
< 3 sec.
> 30 kW
< 5 sec.
5.4.3 Rotation
direction.
Check
Check the motor rotation direction by starting
up and immediately shutting down. The
rotation direction must correspond with that shown by the
pump arrow located on the pump casing or support. If the
rotation direction is not correct, any two phases L1, L2 or L3 of
the power cable must be inverted in the motor terminal box.
Note
The incorrect rotation of the pump may lead to the
incorrect operation of the seal and the heating of its
faces. For this reason, correct rotation direction must be
ensured using the arrow shown on the pump, with the pump
completely filled with liquid and properly vented.
6 Start-up
Before starting up, both the pump and the mechanical
seal process pipes, where appropriate, must be
completely filled with liquid.
It is necessary to prevent the formation of explosive
atmosphere within the frame and the seal housing.
Although there are interior evacuation conducts which remove
the possibility of the air becoming blocked, it is necessary to
fully vent the pump and its process pipes, when fitted, before
starting up.
Start-up shall be carried out when all the necessary
mechanical, hydraulic, electrical and pneumatic connections
are complete.
Motor checks.
When making the electrical connection, ensure the
type of current and nominal voltage shown on the
motor's factory plate concur with the type of current
and the mains voltage in the place of installation.
Follow the indications described in the motor manual.
