Curs PC si internet cap 9.3 Basics of Cable Installation

9.3 Basics of Cable Installation 9.3.2 Documenting cable runs Instructor Note Cut sheets, floor plans, physical and logical topologies, cable labels, and journal entries are just some of the techniques for properly documenting cable runs. Do not present this as an optional part of cable installation but rather as an integral part of a professional installation job. Whenever you install cable, it is important that you document your actions. You can do this by using a cut sheet as you install the cable. A cut sheet is a rough diagram that shows the locations of the cable runs. It also indicates the numbers of the classrooms, offices, or other rooms, to which the cables have been run. Later you can refer to this cut sheet to place corresponding numbers on all telecommunications outlets and at the patch panel in the wiring closet. You can use a page in your journal to document cable runs. By doing so, you will have an additional layer of documentation for any cable installation. Web Links Cabling Glossary Cable Termination and Installation 9.3 Basics of Cable Installation 9.3.4 Types of labels Instructor Note A systematic alphanumeric labeling system should be used to label cable runs and terminations. Ultimately this information should be stored in a spreadsheet and database for reference and maintenance purposes. Avoid labeling cables, telecommunications outlets, and patch panels with terms such as "Mr. Zimmerman's math class," or "Ms. Thome's art class". This can lead to confusion, years later, if someone who is unfamiliar with these locations needs to perform work involving the networking media that is located there. Instead, use labels that will remain understandable to someone who may work on the system many years in the future. Many network administrators incorporate room numbers in the label information. They assign letters to each cable that leads to a room. Some labeling systems, particularly those in very large networks, also incorporate color coding. For example, a blue label might identify horizontal cabling at the wiring closet only, while a green label might identify cabling at the work area. To understand how this works, imagine that four cables have been run to room 1012. On a cut sheet, these cables would be labeled as 1012A, 1012B, 1012C, and 1012D. The faceplates, where the cables 1012A, 1012B, 1012C, and 1012D connect to the work station patch cords, would also be labeled to correspond to each cable. You should also label each cable connection at the patch panel in the wiring closet. Place the connections so that the labels are arranged in ascending order. This allows easy diagnosis and location of problems, if they should occur later. And, finally, label the cables at each end. Web Links Cabling Glossary Cable Termination and Installation 9.3 Basics of Cable Installation 9.3.5 Preparing cable for routing and labeling Instructor Note An efficient way for installing multiple runs of cable is described. After study and analysis, a determination has been made to run four cables to each room in your school. You have surveyed the routes the cable will follow from the wiring closet to the class room. Now you are ready to run cable. Rather than run the cable four times over the same route, your work will be easier, and you will save time, if you route all four cables at the same time. To do this, you need four spools of cable. Each spool holds 304.8 m of cable. For ease of handling and to prevent kinking, spools are usually packaged in boxes. The cable feeds from a hole in the side of the box, while the spool turns inside. If the spool you are working with ever becomes separated from the box in which it was packaged, never uncoil the cable. If you attempt to do so, the cable will twist and kink. Instead, lay the spool on its side and unroll the cable as you need it. This will prevent the cable from kinking and becoming tangled.To help you keep track of each cable as it comes off its spool, assign a letter to each spool. Place the spools at the central point or wiring closet. Unwind a short segment of cable from each spool. Use a permanent waterproof marker to mark the end of each cable so that it corresponds to the letter assigned to its spool. In this case, you know that the cable will run to classroom 1012, so, include that number with each letter. When you finish, the four cables should be labeled 1012A, 1012B, 1012C, and1012D. To ensure that the labels do not rub off or get cut off (the end) later, mark the cable three times, approximately 60 cm apart. To keep all four cables tied securely together, use electrical tape. Bind the cable ends together along with the end of a pull string. You can ensure that the pull string does not come loose by tying some half-hitch knots around the cables with the pull string, before you tape the ends. Don't skimp on the tape. If the string or cables pull out later on, it could cost you time and money. Web Links Cabling Glossary Cable Termination and Installation 9.3 Basics of Cable Installation 9.3.6 Labeling cable ends Instructor Note The importance of labeling cables at each end is introduced. The need to label cables increases rapidly with the number of cables you are bundling. You can save a lot of troubleshooting time later by labeling the cables properly when they are installed. After you pull the cable along the route you selected earlier, bring it into the classroom. (Note: A future lesson will go into more details regarding some of the techniques used to route cable along walls, inside walls, inside attics, and behind drop ceilings.) Allow enough cable for the ends to reach all the way to each jack location, plus enough excess or slack to reach the floor and extend another 50-90 cm.Go back to the spools of cable at the central point or wiring closet. Use the labels on each spool as a reference, then mark each cable with the appropriate room number and letter. Do not cut the cables unless they have a label. For best results, cut the cable and the pull string with wire snips. This will produce a clean cut that will not result in loss of signal. If you follow each of these steps, the networking media used for the horizontal cabling run should be labeled at both ends. Web Links Cabling Glossary Cable Termination and Installation