Commissioning Notes - Siemens Desigo TRA Mounting And Installation Manual

Notes
Power supply AC 24 V
Permissible load [VA]
Wiring
PL-Link bus
Operating voltage
Bus power supply
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Siemens
Building Technologies
• At least one supply (internal or external) is required for each line, and max. two
supplies (external) are allowed per line.
• Install the power supply unit as close to the network center as possible to
achieve maximum line size.
• The distance between the bus device and the next neighboring PSU may not
exceed 350 meters. As a result:
Even if the power demand from the bus devices does not require it, two
power units must be used depending on the line length.
The PXC3 room automation station also includes an AC24V / 2 A / 48 VA output for
PL-Link / KNX bus devices with increased power consumption that is supplied via
AC 24V rather than via the PL-Link bus.
Voltage drop off between the room automation station and bus devices is maximum
-7 % (-1.7 V).
The table below provides permissible loads based on cable lengths and cable
cross sections.
AWG NO.
Cable cross
section
(diameter)
AWG20 (*)
2
0.5 mm (0.8mm)
AWG18 (*)
2
0.8 mm (1.0mm)
AWG16
2
1.3 mm (1.3 mm)
AWG14
2
2.1 mm (1.6mm)
9.4

Commissioning notes

Observer the following commissioning aspects to commission a PL-Link network as
intended.
Check the bus wiring prior to commissioning, and make sure that the bus line
polarity is not interchanged (terminals PL+ and PL–).
Important: Do not interchange the bus line polarity.
Check the operating voltage wiring to make sure that the devices are connected to
AC 24 V or AC 230 V (as per the technical device information). Apply operating
voltage only after this check.
After switching on operating voltage, you must check whether bus power from the
PXC3 or the PSU is available.
Mounting and installation
PL-Link room bus
Cable length for AC 24 V
10 m 20 m
48 VA 30 VA 12 VA
48 VA 48 VA 20 VA
48 VA 48 VA 32 VA
48 VA 48 VA 48 VA
50 m 100 m 200 m
6 VA
10 VA 5 VA
16 VA 8 VA
24 VA 12 VA
CM111043en_03
3 VA
2013-02-23