Cable Shielding - Siemens Simatic RF600 System Manual

RF600 system planning
4.7 Guidelines for electromagnetic compatibility (EMC)
● When connecting the equipotential bonding conductors to the centralized equipotential
bonding strip (EBS), the power components and non-power components must be
combined.
● The equipotential bonding conductors of the separate modules must lead directly to the
equipotential bonding strip.
Figure 4-8
The better the equipotential bonding in a plant, the smaller the chance of interference due to
fluctuations in potential.
Equipotential bonding should not be confused with protective earthing of a plant. Protective
earthing prevents the occurrence of excessive shock voltages in the event of equipment
faults whereas equipotential bonding prevents the occurrence of differences in potential.
4.7.6

Cable shielding

Signal cables must be shielded in order to prevent coupling of interference.
The best shielding is achieved by installing the cables in steel tubes. However, this is only
necessary if the signal cable is routed through an environment prone to particular
interference. It is usually adequate to use cables with braided shields. In either case,
however, correct connection is vital for effective shielding.
Note
An unconnected or incorrectly connected shield has no shielding effect.
84
Equipotential bonding (EBS = Equipotential bonding strip)
System Manual, xx/2014, J31069-D0171-U001-A15-7618
SIMATIC RF600