Siemens SCALANCE X320-3LD FE Operating Instructions Manual page 319

● The connections between the individual segments of channels must be protected from
corrosion (longterm stability)
● If there are connections between sections of buildings (for example separated by
expansion joints) with their own reference point for the building ground network, a
bonding conductor (equivalent copper crosssectional area ≥10 mm
parallel to the cables. This bonding conductor is not necessary if metal, conducting cable
channels/racks are used.
Note
Bonding conductors are unnecessary if the sections of a system are connected
exclusively using fiberoptic cable (FO).
Notes on systems in which no equipotential bonding is possible
To ensure greater immunity to interference, cables for SIMATIC NET PROFINET and
PROFIBUS are always shielded. Due to the defined shielding property, the shield needs to
make contact at both ends.
In systems in which no equipotential bonding is possible, the current flow via the shield
needs to be prevented. Despite this, to be able to use the shield properties of the cable note
the following:
● Contact the shield at one end with low resistance.
● Connect the other end of the shield to the grounding system using capacitive coupling.
SCALANCE X-300
Operating Instructions, 05/2016, A5E01113043-20
Appendix
A.6 Equipotential bonding
) must be installed
2
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