ET/EP/EH Series Intelligent Flexible Driver Manual
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When the peripheral equipment and the inverter
operate in the same power supply system, the
noise generated by the inverter propagates along
the power line, which may cause the
misoperation of other peripheral equipment
connected in the system.
Install a noise filter at the input end of the inverter, or
isolate other peripheral devices from noise with an
isolation transformer/power filter.
If the peripheral equipment, such as control
computers, measuring instruments, radio devices,
sensors and other weak current devices and their
signal lines, is installed in the same control
cabinet with the inverter and the wiring is close
to the inverter, it will cause misoperation due to
radiation interference.
1. The susceptible peripheral devices and their
signal lines should be installed as far away from
the inverter as possible. The signal lines should
be shielded lines, with the shielding layer
grounded, and the signal cables sheathed into the
metal tube and stay as far away from the inverter
and its input and output cables as possible. If the
signal line must pass through the input and output
cables of the inverter, they must be orthogonal.
2. Install the radio noise filter or linear noise filter
(ferrite common mode choke) on the input and
output sides of the inverter respectively, which
may suppress noise radiation from input and
output cables of the inverter;
3. The cable from the inverter to the motor should
be placed in a thick barrier, such as a pipe more
than 2mm thick or a cement tank. The cable
should be sheathed into a metal tube and shielded
and grounded (the motor cable can be a 4-core
cable, one of which is grounded at the inverter
side and the other side is connected to the motor
shell).
A.2 Distribution requirements
A.2.1 Cable laying requirements
In order to avoid interference with mutual coupling, the control signal cable should be laid separately
from the power cable and the motor cable to ensure a sufficient distance as far as possible, as shown
in Figure A-3(a). When the control signal cable must pass through the power cable or the motor
cable, the orthogonal crossing between them should be ensured, as shown in Figure A-3(b).
Power supply or motor
cable
(b) Orthogonal crossing wiring
Figure A-3 Wiring Requirements
A.2.2 Requirements for cable cross-sectional area
The larger the cross-sectional area of the cable, the greater the capacitance to the ground and the
greater the leakage current to the ground. Therefore, if the cross-sectional area of motor cable is too
large, it should be derated to reduce the output current (the current will be reduced by 5% for each
increase of the cross-sectional area).
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