INVT GD200A-004G-4, Руководство по эксплуатации

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GD200A series VFD Peripheral options and parts
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Refer to chapter Technical data for the EMC requirements.
A symmetrical shielded motor cable (see the figure below) must be used to meet the EMC
requirements of the CE.
A four-conductor system is allowed for input cabling, but a shielded symmetrical cable is
recommended. Compared to a four-conductor system, the use of a symmetrical shielded cable
reduces electromagnetic emission of the whole drive system as well as motor bearing currents and
wear.
Shield
Jacket
Insulation
Conductor
PE
PEconductorandshield
Jacket
Insulation
Conductor
Jacket
Insulation
Conductor
PE
Symmetrical shielded cable Four conductor cable
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Note: A separate PE conductor is required if the conductivity of the cable shield is not sufficient for
the purpose.
To function as a protective conductor, the shield must have the same cross-sectional area as the
phase conductors when they are made of the same metal.
To effectively suppress radiated and conducted radio-frequency emissions, the shield conductivity
must be at least 1/10 of the phase conductor conductivity. The requirements are easily met with a
copper or aluminum shield. The minimum requirement of the motor cable shield of the drive is
shown below. It consists of a concentric layer of copper wires. The better and tighter the shield is,
the lower the emission level and bearing currents.
Cross-section of the cable
Insulation course
Wire screen
C.4.2 Control cables
All analog control cables and the cable used for the frequency input must be shielded. Use a
double-shielded twisted pair cable (Figure a) for analog signals. Employ one individually shielded
pair for each signal. Do not use common return for different analog signals.
Double-shielded twisted
Multi-pair cable
Single-shielded twisted
Multi-pair cable
A double-shielded cable is the best alternative for low-voltage digital signals, but a single-shielded or
unshielded twisted multi-pair cable (Figure b) is also usable. However, for frequency input, always