Goodrive350 IP55 High-ingress Protection Series VFD
Optional peripheral accessories
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The maximum temperature margin of the motor cables in continuous operation cannot be
lower than 70°C.
The conductivity of the PE grounding conductor is the same as that of the phase conductor.
For models higher than 30 kW, the cross sectional area of the PE grounding conductor can
be slightly less than the recommended area.
For details about the EMC requirements, see Appendix B "Technical data".
To meet the EMC requirements stipulated in the CE standards, you must use symmetrical
shielded cables as motor cables (as shown in the following figure).
Four-core cables can be used as input cables, but symmetrical shielded cables are
recommended. Compared with four-core cables, symmetrical shielded cables can reduce
electromagnetic radiation as well as the current and loss of the motor cables.
Shield layer
Jacket
Insulator
Conductor
PE
PE conductor and
shield layer
Jacket
Insulator
Conductor
Jacket
Insulator
Conductor
PE
Symmetrical shielded cable
Four-core cable
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Note:
If the conductivity of the shield layer of the motor cables cannot meet the requirements,
separate PE conductors must be used.
To protect the conductors, the cross-sectional area of the shielded cables must be the same as
that of the phase conductors if the cable and conductor are made of materials of the same type.
This reduces grounding resistance, and thus improves impedance continuity.
To effectively restrict the emission and conduction of radio frequency (RF) interference, the
conductivity of the shielded cable must at least be 1/10 of the conductivity of the phase
conductor. This requirement can be well met by a copper or aluminium shield layer. The
following figure shows the minimum requirement on motor cables of a VFD. The cable must
consist of a layer of spiral-shaped copper strips. The denser the shield layer is, the more
effectively the electromagnetic interference is restricted.
Figure D-1 Cross-section of the cable
Insulating layer
Shield layer
D.4.2 Control cables
All analog control cables and cables used for frequency input must be shielded cables. Analog
signal cables need to be double-shielded twisted-pair cables (as shown in figure a). Use one
separate shielded twisted pair for each signal. Do not use the same ground wire for different
analog signals.
