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CHAPTER 3 - INSTALLATION AND CONNECTION
ATTENTION!
Do not use the neutral from the main power supply to ground the inverter.
EMI
When electromagnetic interference (EMI), generated by the inverter, causes
problems with other equipment, use shielded wires or install the motor wires in
metallic conduits. Connect one end of the shielding to the inverter grounding
point and the other end to the motor frame.
Motor frame
Always ground the motor frame. Ground the motor in the panel where the inverter
is installed or ground it to the inverter. The inverter output wiring must be laid
separately from the input wiring, as well as from the control and signal cables.
ATTENTION!
For IT networks (also known as ungrounded or high earthing impedance
networks) it is necessary to consider the following:
Models 180 A to 600 A/380-480 V, 2.9 A to 79 A/500-600 V, 107 A to 472 A/
500-690 V and 100 A to 428 A/660-690 V have a varistor and capacitor
connected between input phase and ground that must be disconnected if an
IT network is used for that, remove the jumper as shown in figure 3.11.
In 500-600 V/500-690 V/660-690 V models, the jumper is accessible taking
out (models 2.9 A to 14 A/500-600 V) or opening (models 22 A to 79 A/500-
600 V, 107 A to 211 A/500-690 V and 100 A to 179 A/660-690 V) the front
cover or taking out the connections cover (247 A to 472 A/500-600 V and 225 A
to 428 A/660-690 V).
In models 180 A to 600 A/380-480 V, besides opening or taking out the front
cover(s), it is required to remove the control board mounting plate (shield).
The external RFI filters that are necessary in order to fulfill the requirements
of European EMC Directive as stated in item 3.3, cannot be used with IT
networks.
The user must check and assume the responsibility of personnel electrical
shock risk when using inverters in IT networks.
About the use of a differential relay at the inverter input:
- The indication of phase-to-ground short-circuit must be processed by the user,
in order to indicate only a fault message or to turn off the inverter.
- Check with the relay manufacturer its proper operation with frequency inverters,
because of the existing high-frequency leakage currents flowing through the
inverter, cable and motor parasitic capacitances to the earth.
3.2.5.4
IT Networks
