CABLING SYSTEM INSTALLATION

Installation Quality The quality of installation is the most serious problem in implementation of the telecommunications cabling systems designed for the high-speed applications support There is a special system of requirements and conditions to the installation of the cabling systems to preserve the primary transmission characteristics of individual components within the links, channels, and systems Whereas the rules of installation are the methods and accuracy of the component connections and cable organization and routing, the cabling rules are an important factor of the system capacity, simplifying the operation of the installed cabling systems

Installation Quality Significant reduction of the signal distortion may be achieved by the observance of the following requirements: –Usage of special methods of the cable preparation –Termination of the transmission media at the connecting hardware according to the manufacturer’s instructions –Ordered arrangement of the cable bundles –Correct spatial orientation of the connecting hardware –Observance of the installation rules and manufacturer’s requirements to the installation of the telecommunications connecting hardware.

CABLE INSTALLATION

Cable Installation  6 Cable ties applied to form cable bundles shall be loose enough to allow the cable tie to slide around and along the cable bundle. The cable ties shall not be tighten so snugly as to deform the cable sheath

Minimum Bend Radius The small bend radii are to be maintained for the twisted-pair cable because of the deformation and inconsistencies of the transmission media inside of the cable occurring at the pair kinks This causes a serious deterioration of such parameter as NEXT Any attempts of bend straightening may be ineffective for the pair shape restoration and may have even worse effect

Minimum Bend Radius In case of the optical fiber cables, if their bend radius is under permissible value, it may increase the losses incurred owing to the macro- and microbends and even the fiber fractures

Minimum Bend Radius Illustration of the “minimum permissible cable bend radius” notion

Minimum Bend Radius  9 The minimum Horizontal and Backbone subsystem cable bend radii shall be: –4-pair UTP cables: under no-load conditions – 4 times the cable diameter under load conditions – 8 times the cable diameter –4-pair FTP, ScTP, SFTP cables: under no-load conditions – 8 times the cable diameter under load conditions – 10 times the cable diameter –multipair twisted-pair cables: under no-load conditions – 10 times the cable diameter under load conditions – 15 times the cable diameter under continued on next slide

Minimum Bend Radius  9 The minimum Horizontal and Backbone subsystem cable bend radii shall be: –intra-building optical fiber cables, 2 and 4 fibers: under no-load conditions – 25 mm (1 in) under load conditions – 50 mm (2 in) –intra-building optical fiber cables, more than 4 fibers: under no-load conditions – 10 times the cable diameter under load conditions – 15 times the cable diameter –inter-building optical fiber cables: under no-load conditions – 10 times the cable diameter under load conditions – 20 times the cable diameter continued on next slide

Minimum Bend Radius  9 If the manufacturer’s requirements to the minimum bend radius of the certain cable are stricter than those specified above, the manufacturer’s requirements shall be observed

Minimum Bend Radius  1 The minimum recommended bend radius for the equipment and patch cables (cords) in service should be: –4-pair unscreened and screened twisted-pair cords – 4 outside cable diameters –optical fiber cords – 25 mm (1 in) To observe these requirements it is recommended to use specially designed means and devices

Maximum Pulling Tension On the cable installation and in some cases in their service (vertical segments) they are affected by the tensile load causing the pair deformation in the twisted-pair cables and mechanical damage of fibers in the optical fiber cables Therefore one of the basic installation requirements together with the bend radius is observance of the maximum permissible tensile load of the cables

Maximum Pulling Tension  10 The tensile load of the cables within the Horizontal and Backbone subsystems during installation and in service shall not exceed: –4-pair unscreened and screened twisted-pair cables – 110 N (25 lbf) –multipair twisted-pair cables – manufacturer’s specifications continued on next slide

Maximum Pulling Tension  10 The tensile load of the cables within the Horizontal and Backbone subsystems during installation and in service shall not exceed: –2- and 4-fiber indoor optical fiber cables – 220 N (50 lbf) or the manufacturer’s specifications, whatever is stricter –indoor optical fiber cables with the number of fibers of over 4 – the manufacturer’s specifications –outdoor optical fiber cables of – 2,700 N (600 lbf) or the manufacturer’s specifications, whatever is stricter

Maximum Pulling Tension When the complex installation is expected with an increased cable load, for example, when the cable is pulled through the closed pathway of over 30 meters (100 ft) long or the pathway with more than two 90° angle turns, the use of a dynamometer or a gauge swivel is recommended After the installation the cable should be put at rest except for the vertical segments, while the residual tension may be caused by the cable dead weight

Media Termination  11 To maintain the cable geometry, the cable sheath shall be removed only as much as required to terminate the cable pairs on the connecting hardware. The connecting hardware manufacturer ’ s instructions for cable sheath strip-back shall be observed

Media Termination  3 The maximum distance of 4-pair cable sheath removal is recommended to be less than 75 mm (3 in) to the conductor termination point

Media Termination  12 When terminating cable on connecting hardware, the cable pair twists shall be maintained as close as possible to the termination point. The distance from the termination point to the nearest pair lay node may not exceed: 13 mm (1/2 in) – category 5e, 6 and 6a cables 75 mm (3 in) – category 3 cables

Media Termination