Curs PC si internet cap 9.2 RJ-45 Jack and Outlet Installation
9.2 RJ-45 Jack and Outlet Installation 9.2.1 TIA/EIA-568-A standards Instructor Note The diagram for the TIA/EIA-568-A and TIA/EIA-569 standards is repeated from an earlier chapter. Convey to the students that each "link in the chain" is governed by standards. In this section the standards which apply to the jack are our focus. Note the standards for Cat 5 horizontal cable run (shown in the graphic) are 3m maximum for workstation cable, 90m maximum for the horizontal cable, and 6m maximum for the patch cord/jumpers -- this gives us the 100m rule. You have learned that horizontal cabling, as defined by TIA/EIA-568-A, is the networking media that connect the telecommunications outlet to the horizontal cross-connect. In this lesson, you will learn how to connect the networking media (in this case, the CAT 5 wire) to the telecommunications outlet (the wall jack). Web Links Cabling Glossary Cable Termination and Installation 9.2 RJ-45 Jack and Outlet Installation 9.2.3 Two methods for mounting an RJ-45 jack Instructor Note The two major types of mounting for RJ-45 jacks are described -- surface mounting and flush mounting. Again, if you have the materials available, passing samples around will help the students visualize what they are learning. The telecommunications outlet in a horizontal cabling scheme is usually mounted on a wall. TIA/EIA-568-A specifies two types of wall mounts that you can use to position an RJ-45 jack onto a wall - the surface mount, and the flush mount. Web Links Cabling Glossary Cable Termination and Installation 9.2 RJ-45 Jack and Outlet Installation 9.2.4 Surface-mounting an RJ-45 jack Instructor Note Screw-mounted and adhesive mounted boxes are introduced as two ways to surface mount an RJ-45 jack. There are two types of boxes that you can use to surface mount RJ-45 jacks to a wall. The first is a screw-mounted box. The second type of box that you can use is an adhesive-backed box. If you choose to use this method, be aware that after you have installed the box, it cannot be moved. This can be an important factor if you anticipate changes in the room's use or configuration. In order to surface mount an RJ45 jack on a wall you must: Select the RJ-45 jack location Run the wire to the location, either inside the wall or inside surface mounted raceway. Mount the box either with adhesive or screws at the desired location. Feed the wire into the box (from top or from the rear) Punch the wire down onto the RJ45 jack. Insert the jack into a RJ45 faceplate. Attach the faceplate to the box. Web Links Cabling Glossary Cable Termination and Installation 9.2 RJ-45 Jack and Outlet Installation 9.2.5 Advantages of surface-mounting an RJ-45 jack Instructor Note The advantages of adhesive surface mounted jacks are discussed: they are faster to install (reducing labor costs) and they are the only option in some cases. However, once affixed, you can't move them. Many installers prefer to use surface-mounted RJ-45 jacks because they are easier to install. You do not need to cut into the wall; you simply mount the jacks onto the surface of the wall. This means that they are also faster to install. When labor costs are a factor in installing a LAN, this can become an important consideration. Surface-mounted jacks may also be the only choice in some situations. Web Links Cabling Glossary Cable Termination and Installation 9.2 RJ-45 Jack and Outlet Installation 9.2.6 Factors to consider before flush-mounting an RJ-45 jack Instructor Note This target indicator describes the factors that go in to a decision to flush mount an RJ-45 jack. You must take several factors into consideration before you decide to flush mount an RJ-45 jack into a wall. For example, the techniques you use to cut into drywall differ from those that you use to cut into plaster. Therefore, it is important to determine, first, the type of wall material that you will have to work with. Plaster can be a difficult material to work with, because it crumbles easily. Also, it is not always possible for mounting screws to attach securely into the wood lath that is located behind the plaster wall. If this is a concern, you may want to surface mount the jack instead.If there are wide wood baseboards on the wall, you may want to install jacks there, because this wood is a more solid material than the wall itself. If you do choose to place the jack on a wood baseboard, avoid cutting the opening into the bottom 5 cm of the baseboard. If you attempt to place the box in that location, the wall's bottom plate will block you from pushing it in. You should also avoid placing a jack anywhere that it might interfere with trim placed around doors or windows. Finally, the last step is to determine whether the jack is to be mounted in a box, or whether it's to be mounted in a low-voltage mounting bracket. Web Links Cabling Glossary Cable Termination and Installation 9.2 RJ-45 Jack and Outlet Installation 9.2.7 Preparing a drywall surface for a flush-mounted jack Instructor Note We suggest that for the next 3 target indicators you create a mock wall. Using two by fours, you can create a frame on which to mount sections of drywall, plaster, and/or wood. The mock wall will allow students to practice flush mounting without fearing damage to any real walls. The frame of the mock wall can be reused; you will need to periodically replace the wall sections. If you are lucky enough to have a shop, perhaps they can fabricate this for you. If you are lucky enough to have the construction trades offered at your institution, you might form a joint project to install wiring in some of their construction projects. To mount an RJ-45 jack in drywall, follow these steps:Select a position for the jack that will be 30-45 cm above the floor. Drill a small hole in the selected location. Check for any obstructions behind the hole by bending a piece of wire, inserting it into the hole, and rotating it in a circle. If the wire hits something, you know there is an obstruction there and must select a new location farther away from the first hole. Then you must do the last procedure again until you find an unobstructed location. Determine the size of the opening you will need, for the box that will hold the jack, by tracing an outline of the template that was included with the box or bracket. Before you cut into the wall, use a carpenter's level to make sure the opening will be straight. Use a utility knife to cut the opening. Push the knife through the drywall, inside the template outline, until you have an opening that is large enough to accommodate the blade of either a keyhole saw or a drywall saw. Insert the saw into the hole, and cut along the edge of the penciled outline. Continue cutting, carefully, along the line until you can pull out the piece of drywall. Make sure the box or bracket will fit the opening. If you're using a box to flush-mount the jack, do not secure the box until after you bring the cable to the opening. Safety ProcedureAny time you are working in walls, ceilings, or attics, it is extremely important that you remember to turn off the power to all circuits that go to, or pass through, the work area! If you are not sure if there are wires that pass through the section of the building in which you will be working, a good rule to follow is to shut off all power. Web Links Cabling Glossary Cable Termination and Installation 9.2 RJ-45 Jack and Outlet Installation 9.2.8 Preparing a plaster surface for a flush-mounted jack Instructor Note Use the mock wall to practice this skill. It is more difficult to cut into a plaster wall than it is to cut into drywall. To achieve the best results, follow these steps. Determine the appropriate location for the jack. Use a hammer and chisel to remove the plaster from the wall so that the lath behind the plaster is exposed. Use a utility knife to carefully trim plaster away from the lath. Place the template against the lathwork so that it overlaps three strips of lath, equally, at the top and bottom of the opening. Trace an outline around the template. Use an electric saw to cut away the full lath strip that is exposed in the center of the opening. Make several small cuts on the full strip, first on one side, and then on the other. Proceed making these small cuts until you have completely cut through the center lath. Be careful when you do this step. If you attempt to cut all the way through one side before cutting into the other side, the saw will cause the lath to vibrate when you make the second cut. This can cause the plaster around the opening to crack and separate from the lath. Finish preparing the opening by sawing notches in the lath strips at the top and bottom. Web Links Cabling Glossary Cable Termination and Installation 9.2 RJ-45 Jack and Outlet Installation 9.2.9 Preparing a wood surface for a flush-mounted jack Instructor Note Use the mock wall to practice this skill. To prepare the wood for flush mounting a jack, follow these steps:Select the position where you want to place the box. You have already learned that, if you choose to place an RJ-45 jack on a wooden baseboard, you should avoid cutting the box opening into the bottom 5 cm of the baseboard. Use the box as a template, and trace around the outside. Drill a starter hole in each corner of the outline. Insert a keyhole saw, or jigsaw, into one of the holes and saw along the outline until you reach the next hole. Turn the saw and continue cutting until you can remove the piece of wood. Web Links Cabling Glossary Cable Termination and Installation 9.2 RJ-45 Jack and Outlet Installation 9.2.11 Procedure for placing the copper wires into a jack Instructor Note This target indicator is best mastered by giving an RJ-45 jack to everyone and a segment of Cat 5 UTP cable with the jacket stripped. It takes a bit of manual dexterity to position the wires in the jack correctly without creating too much untwist (which can cause noise problems). Common errors include not following the color code properly and too much (> 0.5 ", or 13 mm) untwisting. A LANs performance is closely linked to the quality of its connections. When you use RJ-45 jacks at the telecommunications outlet in a horizontal cabling scheme, the wiring sequence is critical to ensure the best possible network performance. Sequencing refers to the process of matching the wires of a cable to the proper terminals on the jack. To understand how this works, examine an RJ-45 jack, closely. Notice that the jack is color coded. The colors - blue, green, orange, and brown - correspond to the colors of the wires in each of the twisted pairs of CAT 5 UTP. Following, are the steps you must use to place the cable wires into the jack:Strip the jacket (coating) from the end of the cable that you want to connect to the jack. Try not to strip any more of the cable jacket than is necessary, approximately 2.5 cm. If you strip too much, data throughput will be reduced. Place the wires in the center of the jack, and keep them there while you work. Wires that are skewed can slow down the rate of data transmission. Also, make sure that you keep the portion of the cable, still covered by the jacket, within 3 mm of the jack. Separate out each pair of twisted wires. The first color that appears on the left side of the jack is blue. Find the pair of wires that contains the blue wire, and untwist them. Lay the blue wire on the slot, on the left, that is color coded blue. Lay the second wire of this pair on the slot, on the right, that is color coded blue and white. The color used to code the next slot on the right side of the jack is green. Locate the twisted pair that contains the green wire, and untwist them. Lay the green wire on the slot, on the right, that is color coded green. Lay the second wire of this pair on the slot, on the left, that is color coded green and white. Continue in this fashion until all of the wires have been matched to their corresponding color-coded slots in the jack. After you have completed these steps, you are ready to punch the wires down into the slots in the jack. Web Links Cabling Glossary Cable Termination and Installation 9.2 RJ-45 Jack and Outlet Installation 9.2.12 Procedure for punching wires down into a jack Instructor Note The punch-down procedure is described. The most common error is that students will have the blade facing the wrong way, and cut off the wire inside the jack instead of trimming the excess wire from outside the jack. You may want to point out that this same procedure is used to punch down into a patch panel, another necessary skill for cable installation. Lab Activity In this lab, you will learn the correct process for terminating a RJ-45 jack as well as the correct procedure for installing the jack in a wall plate. To punch down the wires into the jack, you need to use a punch tool. A punch tool is a device that uses spring-loaded action to push wires between metal pins, while at the same time, skinning the sheath away from the wire. This ensures that the wire makes a good electrical connection with the pins inside the jack. The punch tool also cuts off any extra wire. When you use the punch tool, you must begin by positioning the blade on the outside of the jack. If you place the blade on the inside of the jack, you will cut the wire short of the connection point. If this happens, no electrical connection can occur. (Note: If you tilt the handle of the punch tool a little to the outside, it will cut better.) If any wire remains attached, after you have used the punch tool, simply twist the ends gently to remove them, then, place the clips on the jack, and tighten them. To snap the jack into its faceplate, push it in from the back side. Make sure that when you do this that the jack is right-side up. Then, use the screws to attach the faceplate to either the box, or to the bracket.If you have surface mounted the box, keep in mind that it may hold 30-60 cm of excess cable. You need to either slide the cable through its tie-wraps, or pull back the raceway that covers it, in order to push the rest of the excess cable back into the wall. If you have flush-mounted the jack, all you need to do is push the excess cable back into the wall. Web Links Cabling Glossary Cable Termination and Installation 9.2 RJ-45 Jack and Outlet Installation 9.2.13 Installing RJ-45 jack and outlet Instructor Note This is simply a mastery target indicator to assure that everyone in the class has actually performed the lab tasks. Demonstrate your ability to flush mount an RJ-45 jack in drywall, in plaster, and in wood. Also, demonstrate your ability to lay and punch down wires in an RJ-45 jack. Web Links Cabling Glossary Cable Termination and Installation
