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Siemens
Desigo TRA Engineering, mounting and installation
CM111043en_09
Building Technologies
Wiring of power lines
2016-02-22
6.3
AC 24 V power lines
6.3.1
PXC3 (power and island bus lines)
The following diagram illustrates basic wiring for power lines for modular room
automation stations using AC 24 V operating voltage as per PELV (Grounding of
near the transformer). SELV without grounding is also admitted.
Installation box 1
Installation box 2
AC 230 V
AC 24 V
N
T1
F1
...A
L
1
1
04
3z
10
F4
X1
F5
2
4
V
~
2
4
V
~
2
4
V
~
2
4
V
~
U1
24V~
K
F3
N1
X1
F4
N2
AC 230 V
AC 24 V
N
T2
F2
...A
L
24V~
AC 24 V
Island bus
T, T2
Safety transformer AC 230 V / AC 24 V as per EN 61 558.
K
Terminal block for star distribution of AC 24 V and .
N1
PXC3 room automation station.
N2
PXC3 room automation station, with separate power AC 24 V
(looped power from T1 admitted but not recommended).
U1
Power supply module TXS1.12F10
X1
Bus connection module TXS1.EF10
F1, F2
Low-voltage fuse, for max. power with AC 24 V.
Max. T 10 A
F3
T 10 A fuse in the PXC3
F4
T 10 A fuse in power supply module.
F5
T 10 A fuse in the bus connection module.
Installation example
Key