NORD Drivesystems BU0090 - Manual (Page 30)

NORDAC AS-Interface Manual
30 BU 0090 GB
3.2 Cable type
A simple 2-wire cable with a cross section of 2 x 1.5mm² should be used for networking. It is recommended
that the yellow profile cable is used. Due to the mechanical profile of the cable, each slave can be simply
connected without danger of incorrect polarity. As the geometrically coded position of the wires is fixed and
there is no obstruction from shielding, the slaves can be connected to the AS interface bus using simple
insulation piercing components. The twin-wire profile coded flat cable must not be twisted, screened and
terminated with a terminal bus resistor. For further information, or which cable type was specified for the AS
interface application, please refer to the AS interface specification.
There are different coloured flat cables for different applications:
Yellow for the AS interface Black for the 24V auxiliary power supply
The warranted transfer speeds or transfer distances without disturbances can only be achieved if the specified
cable parameters are complied with.
The maximum length of the yellow cable without a repeater is 100m including the spur cables and branches of
the free AS interface topology. The maximum length of the black cable depends on the power consumption of
the actuators and is normally shorter than the length of the yellow cable. The permissible voltage range direct
to the actuators must be checked.
3.3 Cable layout and shielding (EMC measures)
Without EMC measures, high frequency interference, which is mainly caused by switching processes or
lightning often has the effect of interfering with electronic components in the bus participants and error-free
operation is no longer ensured. Correct laying of the bus cable dampens the electrical influences which may
occur in an industrial environment. Bus lines should be laid with a minimum spacing of 20cm to other lines
which carry a voltage higher than 60V. This applies to lines laid inside and outside of control cabinets.
A separate cable should be used for each AS interface conductor, i.e. AS interface cables should not be laid
with other AS interface conductors or other power circuits in a common cable.
If however, e.g. single wires are used in a switching cabinet, both wires for AS+ and AS- should always be
installed in pairs and twisted wherever possible.
NOTE
For applications with frequency inverters AC line input (mains) filters, or if necessary output
chokes and shielded motor cables should be used.
When laying the cables, as great a distance as possible should be maintained between potential
sources of interference such as frequency inverters and their cables.
3.4 Recommendations of the AS International Association
Please take special note of the information from the "Technical Guidelines" of the AS International Association:
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Installation recommendations, hints and tips for AS interfaces
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Installation hints
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Complete Specification 3.0 Rev. 0
This information can be found on the Internet page
www.as-interface.net , under the heading
Software/Publications.