Siemens 6GK1 901-1GB01 System Manual page 102

Installing network components in cabinets
3.3 Guidelines for setting up networked automation systems in buildings
Pull preassembled cables using cable grips
To pull preassembled cables, make sure that you use cable grips. These surround the
connector and protect it from damage when pulling in the cable.
Fitting strain relief
Make sure that you provide strain relief approximately 1 m from the connection point on all
cables subject to tensile force. Shield clamps are not adequate for strain relief.
Pressure
Too much pressure on the cables must also be avoided, for example crimping the cable
when securing it in position.
Torsion
Torsion can lead to the elements of a cable being displaced and degrading the electrical
characteristics of cables. Bus cables must therefore not be twisted.
Bending radiuses
To avoid damage within the bus cables, they must at no time be bent more sharply than the
minimum bending radius. Note the following:
● The permitted bending radii are larger when pulling in the cable under tensile strain than
● Bending radii for noncircular cables apply only to bending the flat, broader surface. Bends
The permitted bending radii for your bus cable can be found in the technical data sheets of
the bus cables.
Avoid loops
When laying LAN cables, roll them tangentially from the cable drum or use appropriate rotary
tables. This prevents loops forming and resulting in kinks and torsion.
Installing other cables
Remember that cables must not be subjected to excessive strain and stress when installed.
This can, for example, happen when cables are installed along with other cables on a
common rack or in a common duct (providing this is electrically permitted) and when new
cables are pulled along the same path later (during repairs or when extending a system).*
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in the fixed, installed state
in the narrower surface require much greater radii.
Passive network components
System Manual, 02/2013, C79000-G8976-C282-01