Cable Routing Inside Buildings - Siemens SIMATIC S7-300 Hardware And Installation Manual

Appendix
• The lower the impedance of an equipotential conductor, the more effective is
equipotential bonding.
• When shielded signal cables interconnect two system components and the
shielding is connected on both ends to ground/protective conductors, the
impedance of the additionally installed equipotential conductor must not exceed
10% of the shielding impedance.
• The cross-sectional dimension of an equipotential conductor must be sufficient
to handle the maximum equipotential current flow. Practical and proven
equipotential conductor cross-section is 16 mm
• Always use equipotential conductors made of copper or galvanized steel.
Always connect the cables on a large surface to the equipotential
busbar/protective conductor and protect it against corrosion.
• Route your equipotential conductor to minimize the area between the
equipotential conductor and signal lines as far as possible (see the figure
below).
Figure 11-5 Equipotential bonding
11.2.7

Cable routing inside buildings

Introduction
Inside buildings (inside and outside cabinets), clearances must be maintained
between groups of different cables to achieve the necessary electromagnetic
11-14
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S7-300 Programmable Controller Hardware and Installation
A5E00105492-01