Specifications

130BA048.13
L1
L2
L3
PE
Min. 16 mm
2
Equalizing cable
Control cables
All cable entries in
one side of panel
Earthing rail
Cable insula-
tion stripped
Output con-
tactor etc.
Min. 200mm
between con-
trol cables,
motor cable and
Motor cable
Motor
, 3 phases and
PLC etc.
Panel
Mains-supply
mains cable
PLC
Protective earth
Reinforced protective earth
Illustration 5.104 EMC-correct Electrical Installation of a Frequency Converter in Cabinet
5.7.2 Use of EMC-Correct Cables
Danfoss recommends braided screened/armoured cables to
optimise EMC immunity of the control cables and the EMC
emission from the motor cables.
The ability of a cable to reduce the incoming and
outgoing radiation of electric noise depends on the
transfer impedance (Z
T
). The screen of a cable is normally
designed to reduce the transfer of electric noise; however,
a screen with a lower transfer impedance (Z
T
) value is
more effective than a screen with a higher transfer
impedance (Z
T
).
Transfer impedance (Z
T
) is rarely stated by cable manufac-
turers but it is often possible to estimate transfer
impedance (Z
T
) by assessing the physical design of the
cable.
Transfer impedance (Z
T
) can be assessed by the
following:
•
The conductibility of the screen material.
•
The contact resistance between the individual
screen conductors.
•
The screen coverage, which is the physical area of
the cable covered by the screen, often stated as a
percentage value.
•
Braided or twisted screen type.
How to Install VLT® HVAC Drive FC 102 Design Guide
152 MG16C102 - Rev. 2013-08-20
5
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