Siemens SIMATIC NET PROFIBUS, Owner'S Manual

Page: 286 / 490

Installing LAN Cables
C-24
PROFIBUS Networks SIMATIC NET
6GK1970-5CA20-0AA1 Release 2 05/2000
C.8 Additional Instructions on Installing Fiber-Optic Cables
Protecting Connectors from Contamination
Fiber-optic cable connectors are sensitive to contamination. Unconnected male
and female connectors must be protected with the supplied dust caps.
Attenuation Variations under Load
During installation, the fiber-optic cables must not be twisted, stretched or crimped.
The specified limit values for tensile strain, bending radii and temperature ranges
must be adhered to. During installation, the attenuation values can vary slightly,
these variations are, however, reversible providing the strain limits are not
exceeded.
Using the Pulling Loop, Protecting Connectors
Preassembled SIMATIC NET PCF fiber–optic cables are supplied with a pulling
loop and Kevlar sleeve to allow them to be pulled. Make sure that you only connect
your traction device to this loop. You will find detailed instructions about using the
loop in Appendix D.
Fitting Strain Relief
Although the BFOC connectors have integrated strain relief and provide protection
against kinking, it is advisable to secure the cable additionally as close as possible
to the connector to protect it from mechanical stress.
Plan Adequate Attenuation Reserves
When installing the cables over long distances, it is advisable to include one or
more future repair splices in the power loss budget.
Electromagnetic Immunity
Fiber-optic cables are immune to electromagnetic interference. This means that
the cables can be laid in conduits along with other cables (for example
230 V/380 V power supply cables) without any problems occurring. When the
cables are installed in cable conduits, make sure that when other cables are pulled
through, the maximum strain on the fiber-optic cables is not exceeded.