Control Cable Selection; Co-Axial Cable - ABB ACA 6 Series Hardware Manual

Chapter 3 – Electrical Installation
Control Cable
Selection

Co-axial Cable

3-4
All control cables must be shielded. As a general rule, the control
signal cable shield should be earthed directly in the ACx 600. The other
end of the shield should be left unconnected or earthed indirectly via
some nanofarad high-frequency, high-voltage capacitor (e.g. 3.3 nF /
3000 V). The screen can also be earthed directly at both ends if they
are in the same earth line with no significant voltage drop between the
end points.
Twisting the signal wire with its return wire reduces disturbances
caused by inductive coupling. Pairs should be twisted as close to
terminals as possible.
A double shielded twisted pair cable (Figure a, e.g. JAMAK by NK
Cables, Finland) must be used for analogue signals and the pulse
encoder signals. Employ one individually shielded pair for each signal.
Do not use common return for different analogue signals.
A double shielded cable is the best alternative for low voltage digital
signals but single shielded twisted multipair cable (Figure b) is also
usable.
a
A double shielded twisted
pair cable
The analogue and digital signals should be run in separate, screened
cables.
Relay-controlled signals, providing their voltage does not exceed 48 V,
can be run in the same cables as digital input signals. It is
recommended that the relay-controlled signals be run as twisted pairs.
Never mix 24 VDC and 115 / 230 VAC signals in the same cable.
Recommendations for use with ACS 600 MultiDrive Application
Controller:
• 75 W type
• RG59 cable with diameter 7 mm or RG11 cable 11 mm
• The maximum cable length is 300 m
ACA 6xx Sections and ACS/ACC 6x7 (132 to 3000 kW) Frequency Converters
b
A single shielded twisted
multipair cable