【 Weak current College 】 on shielded cabling system installation

As the technology is mature and stable, in high-end routing project, some or all of the use of shielding systems engineering case gradually increased, and the associated installation problems are not uncommon. From many of the works, the majority of shielding system installation problems are concentrated in the workspace and distribution frame sides, cable laying relatively few problems, forming a dumbbell structure. But these problems can be traced to the lack of understanding at the design stage, thereby ignoring some of the details. If shielded module size dimensions more general non-screened products and generous, not suitable for multiple modules stack; shield cable outer diameter of a non-shielded cables, hardness increase, the installation of pipe Groove reserved size, cable bending radius will be affected. The author contacted better shield project, involving Government, military, Enterprise, industry, engineering and implementation of some experience, and performance of the share exchange.

First note that terminal information point mounting density. Once a government site to see, a conventional 4 panel full distribution installed four large shielding modules, redundant cables inside the Panel is raised and deformation, such violence installation will inevitably occur in the later use. At the time of planning, you should consider using single-port, dual panel installation forms a stack of shielding modules, and bottom boxes inside of cable positive crowded, the client contacts the cable twisted folded bit distortion would increase, and affect the actual performance.

Secondly, the depth of the bottom box, combined with the manufacturer's production indicators, the General line of six types of masking, around the outside diameter, hyper-v 7.2mm class shielded cable outer diameter on the left and right, in accordance with the international 6.1mm cabling standards, shielded cable bending radius to diameter 8 times, this is the normal 70 × 70mm dimensions (width x height) in the bottom box, is a bit not enough, so taken to deepen the bottom box, makes redundant cables to extend the internal depth to basic indicators meet bending radius; another reason is the shielding modules of body size and length is larger, consideration should be given to the module in the Panel after installation depth, as well as satisfy the reasonable shielding the cable end module bending required depth, so we need to deepen the bottom box. Effect from the actual construction, six types of shielding system, the best depth should be at the end box, hyper-v class 8mm shielding, to at least 6mm depth.

For shielding modules installed in the ground, it is necessary to pay attention to the cable from the wall next to the floor may have more than one turn, and the associated metal tube should be used in a larger aperture (recommended 25mm) type, and to minimize the use of large angle pour; ground installation normally using a metal insert, insert mainly includes the up-and open-type two, open-to-large internal space and screw-adjustable bottom box in the depth of ground installations (usually from 55-85mm), if the floor with a thick, allows deep, is a very good choice; in many cases, to not destroy the bearing structure, floor allow sinking depth is typically less than 50, which should be in the up-and-insert. In the up State, shielding modules together with beveled frame highlights the ground at a distance, so you can give the bottom box redundant cables more secure disk spaces.

Cable in the bottom box set aside also need attention. The current shield module main card received-and no-tool installation of two types, the most convenient tool module, generally installed in a separate tail cover the four lines on the handle, and then bite into the shielding cavity, this approach does not require the card received tools, cables can be shorter reservation; card-shielded module received due to a termination tools scene cards next thread if you reserved short will cause inconvenience to the construction. A good experience is: in the end box near installed (such as ceiling, ceiling) to reserve a transfer box, Setup Panel, bottom box part redundant cables back to transit box for example, to reduce the congestion in the bottom box, if the termination problems, need to termination, or to go out redundant line spare cartridges.

Also noteworthy is the shielding system grounding continuity. Termination of the work area, should follow the manufacturer's termination requirements, while it is necessary to pay attention to protect the cable shield not cracked damaged and shielding modules outer good contact; the use of steel or metal cable tray for laying cable, steel pipe, steel bridge and bridge between, should make reliable connections between, and to do cross-Earth wire; wiring between each screen distribution frame should separate earthing, from distribution frame of unified Earth point separate la ground wire to the wiring between the TGB Telecom grounding straps, grounding line use 6mm2 copper conductor, distribution frame-to-ground grounding resistance less than 1 Ω (using joint grounding). Good grounding can prevent mutation of voltage impact damage to the electronic equipment, reduce the electromagnetic interference on the impact of communication transmission rate.

Last note on wiring between shield jumper for effective management. Due to shielding jumper's outer diameter thick, high hardness, taking into account the need for reasonable jumper disc curved and management, cable Manager to choose widening (2U) or better; in addition to prevent the jumper congestion, to a reasonable length, select jumper as a 42U Cabinet internal jump, there is no need to configure the 3-metre-long jumper. Our experience is based on the distribution frame and switch location placed between configuration jumpers a reasonable length.