Emc Compliant Wiring - Siemens Desigo TRA Engineering, Mounting And Installation Manual

Wiring rules
Installation box wiring
Building wiring
Different types of cable in
one cable duct.
Cable types
Separate cables
Shielded cables
Screened cable
Siemens
Building Technologies
5.5

EMC compliant wiring

Below only installation boxes are mentioned. Panels are included.
If heavy EMC disturbance is expected in an installation box or in the building, the
following wiring rules can better protect TRA devices:
In the installation box, separate unshielded lines from shielded lines at the
terminal connections and cable ducts.
Avoid cable loops.
Plan sufficient space to correctly connect the cable screens.
Connect cable screens to the installation box directly at the inlet to the
installation box. Leave screen intact to the module.
The installation box must be grounded/bonded to the building's ground system..
When setting up cable ducts, separate strongly disruptive cables from victims.
Disruptive cable:
TRA devices:
Both types of cables may be in the same cable duct, but should be place is
separate compartments.
If not three-sided duct with separating wall is available, the disruptive cables
must be separated by at least 150 mm / 6 in from the others or placed in
separate ducts.
The crossing of strongly disruptive cables should be at a right angle to TRA
cables.
Comply with the manufacturer's installation recommendations for the selection of
shielded or unshielded cables. In general, unshielded twisted pair cables have
sufficient EMC properties for building-technical applications (including data
applications.
Unshielded round wires can also be used for the island bus (wire CS, CD).
Benefit: Unscreened/unshielded cables do not need to be coupled to the
surrounding ground.
Screening/shielding improves EMC properties. Please note the following, however:
The grounding (common reference point), is tasked with diverting and short
circuiting existing interference voltage.
Special emphasis must be placed on the grounding concept to prevent
grounding loops or differences in potential .
Against low-frequency interference: Ground the screen/shield on one side only.
Screens/shields must be connected on both sides with the ground against high
frequencies. Grounding must never take place via the cable screens/shields.
A separate ground must be installed when missing.
Alternative: hard wired earthing on one side, via a capacitor on the other side.
The cable screens/shields must be properly connected to the ground to achieve
a solid level of screening/shielding (see below).
Island bus extension, see: TX-I/O engineering and installation, CM110562)
Desigo TRA Engineering, mounting and installation
Installation box / panel for TRA
Motor cables, energy cables.
Control cables, low-voltage cables, interface cables,
LAN cables, digital and analog signal cables.
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CM111043en_09
2016-02-22