Electrical Connection / Earthing; Terminal Strip Positionning For Star (Y) And Delta () Connection (Multi-Voltages Electric Motors); Lower Voltage :  Connection; Higher Voltage : Y Connection - Wilo MMI50V Instrucciones De Instalación Y Funcionamiento

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7.3 ELECTRICAL CONNECTION / EARTHING

Check that motor winding corresponds to site electric power
supply characteristics before electrical connections are performed.
Connecting a 230/400V motor on a 400V power supply or
connection of a 400/690V motor on a 690V power supply might drive to
motor destruction if terminal strip are positioned in a wrong way.
Electrical connection should be performed by qualified personnel
only having necessary agreements and in compliance with local, national
and international regulations.
Equipments used in an ATEX zone will be connected in compliance
with CEI60079-14. It is the responsibility of the end user to select proper
type and size of electric cable.
Respect motor manufacturer instructions to make electric motor
connection (refer to the instructions supplied with the motor. they are
usually indicated inside motor junction box). Sensors will be connected
in compliance with the instructions given in dedicated instruction
manual.
7.3.1 TERMINAL STRIP POSIT IONNING FOR STAR
(Y) AND DELTA () CONNECTION (MULTI -
VOLTAGES ELECTRIC MO TORS)
Multi-voltage winding for voltages 230/400V and 400/690V :
6 wiring terminals :
To change motor direction of rotation reverse two phases on wiring
terminals. Connection of earthing terminal is mandatory.
LOWER VOLTAGE :  CONNECTION
7.3.2
Voltage : U
7.3.3

HIGHER VOLTAGE : Y CONNECTION

Voltage : U3
14
Y /  STARTER :
7.3.4
Grounding of the complete pumpset will be performed with
special care. Earthing will avoid any electrostatic accumulation in
components of the pumpset. Each part of the pumpset should be
connected to earth with a correctly calibrated bonding strap or cable
(motor winding, motor frame, coupling guard, pump baseframe).

7.4 USE OF A FREQUENCY INVERTER

When pump is used with a variable speed drive, make sure that
the frequency inverter instructions and operating manual is available
and known.
The electric motor that is supplied with the pump may be connected
under conditions to a VSD. Variable speed will be used to reach pump
required duty point on site. To ensure a reliable use of the equipment a
few precautions should be taken :
ELECTRICAL REQUIREMENTS :
- Variable frequency drive will not generate voltage peak higher than
850V (motor phases isolation) and dU/dt values higher than 2500
V/µs (winding isolation). If those values can be reached, a filter
should be installed : ask inverter manufacturer for proper selection
and motor manufacturer for limit values.
- Choose a vector control inverter or use a quadratic V/F control
inverter.
- Check that motor nominal voltage is never exceeded.
Power supply cable should comply to ATEX regulation. Ensure that
motor winding is equipped with CTP temperature sensors inside.
A physical barrier should separate power supply cables and low
voltage cables to avoid analog signal distortion.
HYDRAULIC REQUIREMENTS :
- For all possible speeds, check that the pump NPSH
than system NPSH .
A
MECHANICAL REQUIREMENTS :
- Lower speed should not fall under 40% of pump nominal speed to
avoid any vibrations and an unstable flow.
is always lower
R