Connecting Cable Shields - Siemens SIMATIC S7-1500 System Manual

Communication connections
Equipotential-bonding cables are not required for fieldbus components within a control
cabinet if they are configured as detailed above.
For communication connections between separate parts of a plant (for example devices in
different control cabinets) and between buildings or parts of buildings, you must ensure
potential equalization.
If data lines (PROFINET, PROFIBUS or DRIVE-CLiQ), for example, run through more than
one control cabinet, potential equalization with a potential equalization conductor is required.
Lay the equipotential bonding conductor together with the data line.
The following minimum cross-sections are required pursuant to IEC 60364-5-54:
● At least 6 mm² for copper
● At least 16 mm² for aluminum
● At least 50 mm² for steel
NOTICE
Disruption to data connection or device defect in the absence of equipotential bonding
Considerable leakage current can flow over the data line if no potential equalization is set
up. Disruption to data connection or device defects are possible.
Lay an equipotential bonding conductor together with the data line.
Due to the maximum length of 100 m for PROFIBUS copper cables at 12 Mbps or for
PROFINET copper cables, and aspects of electrical isolation, EMC protection and
equipotential bonding, we recommend using fiber-optic cables for connections between
buildings.
6.10

Connecting cable shields

Using shielded cables
The following options are available for the shield connection when using shielded cables:
● A shield connection using a shielding bus supplied separately
● Shield contact with shield contact element at the top of the SIMATIC Drive Controller
enclosure.
SIMATIC Drive Controller
System Manual, 11/2019, A5E46600094-AA
Connecting
6.10 Connecting cable shields
89