Copper cabling has been in use since electricity was invented and its quality has continued to improve. Network managers pick copper cabling for various reasons. For instance, copper cables, especially UTP cables, are as inexpensive as optical fibers and easy to install. Moreover, the installation methods are well understood, and the components (patch panels, wall-plate outlets, connecting blocks, etc.) are inexpensive. This article will provide guidelines for copper cabling installation.
One of the most important elements to plan and deploy a telecommunication infrastructure is to make sure you are following the ANSI/TIA-568-C standard. This standard will ensure that your cabling system is interoperable with any networking or voice applications that have been designed to work with that standard.
ANSI/TIA-568-C standard defines the maximum distance that a horizontal cable should traverse. The tips relating to distance and the installation of copper cabling include following:
Never exceed the 90-meter maximum distance for horizontal cables.
Horizontal cable rarely goes in a straight line from the patch panel to the wall plate. Don’t forget to account for the fact that horizontal cable may be routed up through walls, around corners, and through conduit.
Account for any additional cable distance that may be required as a result of trays, hooks, and cable management.
Leave some slack in the ceiling above the wiring rack in case re-termination is required or the patch panel must be moved. Some professional cable installers leave the extra cable loop in the ceiling bundled together or looped around a hook, shown as below.
The ANSI/TIA-568-C standard introduces two wiring patterns for modular jacks and plugs: T568-A and T568-B. The only difference between these wiring patterns is that pin assignments for pairs 2 and 3 are reversed. The wiring pattern chosen makes no difference to the applications used. They both work the same way. The most important factor is to choose one wiring configuration and stick with it. If you use T568-A at one end, you must use it at the other; likewise with T568-B.
The cable pairs are assigned to specific pin numbers. The pins are numbered from left to right if you are looking into the modular jack outlet or down on the top of the modular plug. The following picture shows the pin numbers for the eight-position modular jack (RJ-45) and plug.
When planning a cabling infrastructure that includes copper cabling, ask yourself some questions before taking action. For example, how many cables should be run to each location? Should you use cable trays, J hooks, or conduit where the cable is in the ceiling space? Or is there a danger of cable damage from water, rodents, or chemicals? Consider any area that cable may be run through and take into account what you may need to do to protect the cable.
Good cable management starts with the design of the cabling infrastructure. When installing horizontal cable, consider using cable trays or J hooks in the ceiling to run the cable. They will prevent the cable from resting on ceiling tiles, power conduits, or air-conditioning ducts. Furthermore, make sure that you plan to purchase and install cable management guides and equipment near patch panels and on racks so that when patch cables are installed, cable management will be available.
When you start installing copper cabling, much can go wrong. Even if you have adequately planned your installation, situations can still arise that will cause you problems either immediately or in the long term. Here are some tips to keep in mind for installing copper cabling.
Do not untwist the twisted pairs at the cable connector or anywhere along the cable length any more than necessary.
Bridged taps are not allowed.
Use connectors, patch panels, and wall plates that are compatible with the cable.
Never splice a data cable if it has a problem at some point through its length; run a new cable instead.
When terminating, remove as little of the cable’s jacket as possible, preferably less than three inches. When finally terminated, the jacket should be as close as possible to where the conductors are punched down.
Don’t lay data cables directly across ceiling tiles or grids. Use a cable tray, J hook, horizontal ladder, or other method to support the cables. Avoid any sort of cable-suspension device that appears as if it will crush the cables.
If you have a cable with damaged pairs, replace it. Don’t use another unused pair from the same cable because other pairs may be damaged to the point where they only cause intermittent problems, which are difficult to solve. Substituting pairs also prevents any future upgrades that require the use of all four pairs in the cable.
Besides the tips above, you should also separate voice and data patch panels. Some installations of voice and data cabling will terminate the cabling on the same patch panel. Although this is not entirely frowned upon by cabling professionals, many will tell you that it is more desirable to have a separate patch panel dedicated to voice applications. This is essential if you use a different category of cable for voice than for data (such as if you use Category 5e cable for data but Category 3 cable for voice).
Take the picture above as an example, the wall plate has two eight-position modular outlets (one for voice and one for data). The outlets are labeled V1 for voice and D1 for data. In the telecommunications closet, these two cables terminate on different patch panels, but each cable goes to position 1 on the patch panel. This makes the cabling installation much easier to document and to understand.
Copper cabling installation is not as easy as thought. You should follow the ANSI/TIA-568-C standard to confirm the cable distance and wiring patterns. And before installation, you’d better ask yourself some questions that you may meet during cable installing. Moreover, take the tips mentioned above when you begin to install copper cables. Hope the information mentioned in this article would be useful for you when needed.