Siemens SIMATIC NET PROFIBUS manual Cabling outside Buildings, EMC Rules for Electrical LAN Cables

Installing LAN Cables

C.5.4 Cabling outside Buildings

Fiber-optic cables should be given preference

For communications between buildings and between buildings and external facilities, the use of fiber-optic cables is generally recommended. Due to the optical transmission principle, fiber-optic cables are not affected by electromagnetic interference. Measures for equipotential bonding for overvoltage protection are unnecessary with fiber-optic cables.

EMC Rules for Electrical LAN Cables

When installing electrical LAN cables outside buildings, the same EMC rules apply as to cables inside buildings. The following additional rules apply:

Sinstall cables on metal cable racks

SElectrically connect the cable racks where they join

SGround the cable racks.

SThere must be adequate potential equalization between buildings and external facilities regardless of the LAN cables. (see section C.4.4 in this manual)

SThe cables should be installed as close as possible and parallel to the equipotential bonding..

SConnect the shields of the cables to the grounding network as close as possible to the point of entry into the building or facility.

SElectrical LAN cables installed outside buildings must be included in the lightening protection and grounding concept of the entire system. Please note the information in Appendix B of this manual.

SAll SIMATIC NET PROFIBUS cables can be used if they are installed in cable channels protected against dampness. In this case, the clearances specified in section C.5.1 of this manual must be adhered to.

PROFIBUS Networks SIMATIC NET	C-17
6GK1970-5CA20-0AA1 Release 2 05/2000