Siemens Simatic S7-300 CPU 31xC Series Installation And Operating Instructions Manual page 225

• Always use equipotential bonding conductors made of copper or galvanized steel. Always
• Route your equipotential bonding conductor to minimize the area between the
S7-300, CPU 31xC and CPU 31x: Installation
Operating Instructions, Edition 08/2004, A5E00105492-05
connect the cables on a large surface to the equipotential conductor bar/protective
conductor and protect it against corrosion.
equipotential bonding conductor and signal lines as far as possible (see the figure below).
A.2 Protection against electromagnetic interference
Appendix
A-15