Network Router User Manual

Assembling and Installing Systems
A-19
Automation System S7-400 Hardware and Installation
A5E00850741-01
A.8 Cabling Outside Buildings
Rules for EMC
When installing cables outside buildings, the same EMC rules apply as for inside
buildings. The following also applies:
• Run cables on metallic cable supports (racks, trays etc.).
• Establish a metallic connection between the joints in the cable supports
• Ground the cable supports
• If necessary, provide adequate equipotential bonding between the various items
of equipment connected.
• Take the necessary (internal and external) lightning protection and grounding
measures applying to your particular application (see below).
Rules for Lightning Protection Outside Buildings
Lay your cables either:
• In metallic conduits grounded at both ends, or
• In concrete cable ducts with continuous end-to-end armoring
Overvoltage Protection Devices
An individual appraisal of the entire plant is necessary before initiating any lightning
protection measures (see Section A.9).
Further Information on Lightning Protection
You w ill find further information in the following sections.