Shielded cabling system is installed in the general Unshielded cabling system with metal shielding layer on the outside of a metallic shield reflection, absorption and skin effect of preventing electromagnetic interference and electromagnetic radiation function.
The major advantages of shielded cabling system embodied in it has a strong resistance to external electromagnetic interference and radio frequency interference ability; But also can prevent the internal energy of the transmitted signal to the outside world radiation, has a good system security. For a shielded cabling system, to reflect its characteristics in the design and construction, we need to pay attention to the following points:
2. Shielded cabling system must be properly installed and grounded, if the transmission channel of the shield connection element is not continuous or poorly grounded, may be higher than unshielded system provides transmission performance even worse.
Figure 1: shows cable, patch panel, module and patch cable
Chapter 1 Shielded cabling system installation
Shielded cabling system installation mainly involves two aspects: floor wiring and workspaces shielded cable termination and system ground.
Based on the particularity of the shielding system, you need to ensure that the cable shielding layer of the range of 360 degrees with the module and patch panel with good contact shield, rather than at some point to connect, but not in the same one shield intermediate link be broken.
Step 1: Use special clamping tool to remove the sheath of the shielded cable
Step 2: Separate 4 of twisted pair cable strip away, do not open the wire pairs, according to the information indicated on the module wire color line sequence, a short pull both hands flat on the corresponding cores, to be placed corresponding slot.
: All core wires are embedded is available after use a Network Cable Crimping Tool
and then a root of the core wire further pressed into the slot. The wire tool blade alignment information and wire trunking on the module, the module outside the excess wire is cut. Repeat this operation, but also to put the cable drain wire and metal sheet rear the module connection.
Step 4: The information module sheet plastic dust penetration twisted along the gap, and fixed on information module, and then covered with metal cover of the module, the module can be completed after pressing making the whole process. Then put the production of information module into information outlet.
Step 5: After information module is made, of course, also you can test the connection wheter is good, use multimeter to measure at this time. The multimeter gear hit the x10 resistance profile, the wildcard beads one hand and the other end of the network cable, core wire corresponding contact information to another multimeter pen touches on the module card into the appropriate card color core wire trunking edge (Note, not touch core wire), if the resistance is small, then the proof information module connections are good, otherwise press down and then hit the corresponding core wire crimping tool until smooth so far. Professional testers can also be used, such as FLUKE and FiberStore, depending on the type of shielding test object selection standard. FiberStore Professional Tester
Figure 2: shown a professional waterproof connectors Crimping Tool
Figure 3 optical multimeter
A completer shielded cabling system installation requirements everywhere shielding, a continuous, complete shielding path in order to achieve user-expected results. If you choose to use shielding system, in addition to cables, modules, patch panels and other connections are required to use shielded, while supplemented by metal tray and pipes. The principle of electrostatic shielding is tomake the interference shielding outer into the earth, thus properly grounded shielding layer is very important.
Chapter 2 Grounding
Properly grounded shield is very important, not only will not reduce interference, but will make interference increases. Because when the arrang-ement is not properly ground, the ground resistance is too large, the ground potential is not balanced, may cause ground noise, that is, in a transmission channel to generate a potential difference between two points, so that the metal shielding layer on the interference current, when the shield itself to form one of the largest sources of interference, causes its performance is much less than the unshielded transmission channel. Therefore, to ensure the screen effect, the shield must be properly grounded.
The ground accessories shielded patch panel is a ground bus, it can be shielded module uniform all through connecting it to grounding body, form the patch panel of the grounding channel.
Shielded patch panel with grounding accessories are mainly two types:
1. Installation within the patch panel of ground accessories
Patch panel installed in the ground accessories have flexible, when shielded cabling system installation module is inserted into the patch panel, its automatic metal shell and accessories to form a good grounding, complete shielded module grounding work.
2. Independent grounding accessories
Independent grounding accessories can be dedicated Unshielded patch panel into shielded patch panels, modules generally contain such shielding bonding wire can be inserted with a grounding connector. When shielded patch panel module is inserted, it will take ground accessories of the cable into the grounding of the shield on the interface module, the module form a shield ground connection.
Patch panel should be fitted with ground piles, so the ground wire from the cabinet can overlap with them. The traditional approach used shielded patch panel is a metal cabinet uprights to ground, this approach is no longer used.
The shield grounding of patch panel can be used in the following ways:
1. Each shielded patch panel through the respective ground wire to the cabinet confluence copper rafts, forming a star-ground structure;
2. Install a grounded copper bottom of the cabinet and a separate ground wire connected to the grounding copper wiring closet (telecommunications room) ground piles (ground copper bars), so that the ground between the various cabinet formed star-ground structures;
3. Ground wire cross-sectional area should be greater than 6mm2;
4. Electrical ground wire ends should use common cold solder pieces, so as not to spread the thread composed of short circuit;
5. In order to improve the discharge capacity of high frequency interference signals suggested that need braided wire grounding wires, with greater surface area to meet the skin effect of high frequency current demands.
Shielded cabling system installation projects, in addition to high quality wire, plug parts, good construction techniques and meticulous work attitude are essential. Focus on the details of the construction process, good shielding system links the various ground, believe that will be able to make high quality of shield project.