User Manual

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Siemens TX-I/O Engineering and installation guide CM110562en_13
Building Technologies Wiring 2019-05-15
6.4.3 Wiring island bus expansion
Wiring material See Section 10.6
Maximum wire length See Section 10.6
Cabling the bus cable • Low-voltage wiring and cabled next wiring mains voltage, must have the same
isolation strength as is used for the mains voltage.
• We recommend separating low-voltage wiring from mains voltage for reasons of
electro-magnetic compatibility. Recommended minimum distance: 150 mm.
Bus topology • Line topology only is allowed
ONE island bus expan-
sion module only per
sub-island
• Cascading (more than one island bus expansion module per sub-island) is not
permitted.
System ground (
⊥
) • The island bus expansion operates without system ground (⊥).
• The system ground (⊥) must be connected when a remote sub-island is powered
by the local sub-island. The ⊥ wire must be routed together with the cable for the
island bus expansion.