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Siemens Desigo Room automation - Engineering, mounting and installation CM111043en_14
Smart Infrastructure KNX PL-Link room bus 2020-10-30
13.3 Cables
The bus lines (= twisted pair) are connected via PL+ (red) and PL– (black).
Choose the bus cable as per country-specific offerings. Comply with values
indicated in this document under "Technical data KNX PL-Link".
AC24V for field supply can be provided in the same (2 x 2 stands) or in a separate
cable.
Recommended bus cable are available on the KNX homepage under Downloads /
Support – 06 KNX Certification – 02 KNX Certified Products – Cable:
http://www.knx.org/downloads-support/downloads/:
1 x 2 x 0.8 mm (e.g. Belden YE00819 or YE00905 - non-halogen).
2 x 2 x 0.8 mm (e.g. Belden YE00820 or YE00906 - non-halogen).
In TRA plants, bus cables without screen are permitted. The screens available for
bus cables do not need to be connected.
If interference is expected on the KNX bus, use a cable with screen. Connect the
screen as per standard installation rules.
The indications for distances and line lengths in a network are designed for bus
cables specified by KNX.
Comply with the following distances :
Network with internal power supply from the room automation station
DXR2 PXC3
· Distance between device and
internal supply
max. 80 m / 260 ft Max. 350 m / 1150 ft
· Distance between devices max. 80 m / 260 ft Max. 350 m / 1150 ft
· Total length of all lines on one line max. 80 m / 260 ft Max. 350 m / 1150 ft
Network with external power supply (PSU) (see section 13.1.2)
· Distance PSU to PXC3 with switched off internal supply Min. 0 m
· Distance device to next PSU Max. 350 m / 1150 ft
· Distance between two PSU operated in parallel Min. 200 m / 650 ft
Min. 0 m for the new Siemens power supply modules recommended
in section 13.1.2.
· Distance between devices Max. 700 m / 2300 ft
· Total length of all lines on one line Max.1000 m / 3280 ft
Important: The bus conductors must NOT be inverted.
(KNX terminals + and –).
+
-
+
-
AC 24 V
T
K
N
X
KNX
Bus lines
Bus cable selection
Recommended cable
types
Bus cable screening
Bus cable: KNX
specified.
Admissible cable
lengths
Polarity