UTP Cable

(Unshielded Twisted Pair)

Installation Notes

Read this before proceeding

These notes are very general in nature and are intended to provide simple, easy to follow guidelines and helpful hints for basic installation projects. These notes are not conclusive and are not intended to substitute for technical training or in depth documentation. If you are not familiar and comfortable with the terms, conventions and tools referenced you should contract a qualified professional to perform this type of work. Whenever working with electrical circuits, proper safety precautions must always be followed. Neglecting proper safety precautions can cause electrical shock hazards, possibly resulting in injury or death. Improper handling of electrical circuits or equipment can result in equipment damage and other adverse effects.

Choosing Cable Type:

There are a range of standard UTP cable types (classifications) commonly used for audio and data communications. These are grouped as “category” types and the category names are therefore prefixed by CAT (as in “category”). The real difference between the categories is that the higher the category level, the tighter the twist of the twisted pairs within the outer cable jacket. The tighter the individual pairs are twisted, the higher the effective bandwidth or data throughput capability. A higher category rating will also carry low level analog audio signals longer distances with less signal loss. When working with standard analog audio circuits or low speed data (such as digital telecommunications signals), typically CAT3 cable is used if there is no foreseeable point where this cable will be expected to carry high speed data (in excess of 10Mbps) and the level of the signal is sufficient given the distance it needs to be carried.

When working with analog or digital (data) cabling or networks you can think of the circuit or network as a plumbing network expected to carry water. The higher the throughput or bandwidth rating, the bigger the pipe would be in this example. In theory a “big pipe” will carry a high volume of water. However there is a catch that is commonly overlooked. The slowest point in any circuit or network will typically be the highest speed of the circuit or that portion of the network. In the water example, if you have a 4” pipe carrying water from one point to another the water will flow at a steady rate for a great distance. If however, the water flows for some distance through a 4” pipe, a short section of the pipe is reduced to a 1” pipe and then the diameter is increased back to a 4” pipe, the throughput of the entire length of pipe will be the maximum volume of water that can pass through the 1” pipe. With this in mind, if you have a circuit or network designed to carry data at 100Mbps but use the wrong type of cross-connect blocks, connection points or do a poor job of installing the cable, jacks or connectors, the entire circuit or network will be reduced to the lowest common denominator, such as the poorly terminated connector or a kinked cable.

CAT3 – Category 3 cable has been the standard cable used in the telecommunications industry for several years and is still used extensively throughout the telecommunications industry. It is inexpensive and readily available in a range of pair configurations within a single outer jacket. These configurations include 2-Pair, 4-Pair, 6-Pair, 16-Pair, 25-Pair and greater. The conductors within these cables are comprised of twisted pairs of solid conductor wires with color coded insulation. The color code of the pairs in a given jacket start with “white/blue” as the first pair and continue the sequence referenced in the color code chart depending on the number of pairs within the jacket.

CAT5 – Category 5 became the default standard in UTP cable when UTP cable became popular for use in data / network communications applications. CAT5 cable typically consists of four twisted pairs within one outer jacket. CAT5 cable is typically rated for data transmission applications up to 100MHz. Although all UTP data cable is commonly referred to as “CAT5 cable”, do not confuse CAT5 with CAT5E. CAT5 cable is identical to CAT5E cable except that CAT5E cable must meet a higher standard relative to the uniformity and tightness of the twist of the pairs. Currently as of this writing (2005) CAT5E is the default standard for all new construction UTP data cabling applications. Because CAT5E cable is the industry standard, is readily available, is higher quality than CAT5 and is essentially the same price as CAT5, the use of CAT5 cable should not be practiced in new installations.

CAT5E – Category 5E cable is the industry standard for new UTP data cable installations. CAT5E cable typically consists of four twisted pairs within one outer jacket. Typical data throughput or bandwidth ratings for CAT5E cable is 100Mbps, although ratings of up to 1000Mbps may be specified and can be attained if stringent standards are maintained such as cable length, termination methods, Etc.

CAT6 – Category 6 is the highest officially certified UTP cable standard. CAT6 cable is identical to CAT5E cable except that it must meet tighter standards relating primarily to a tighter twist of the twisted pairs and sometimes channeling, separating and protecting the individual twisted pairs. The tighter the twist of the twisted pairs of copper conductors, and the better the protection and separation of the individual twisted pairs the lower the incidence of noise or signal loss and therefore the higher the bandwidth or data throughput. CAT6 cable typically consists of four twisted pairs within one outer jacket. When installing 1000Mbps or “GigaLAN” UTP cabling CAT6 cabling should be used.

Solid Conductor vs. Stranded Conductor UTP Cable – All standard UTP cable is made with solid conductors, with the exception of “Jumpers.” Jumpers are the cables typically used for connecting equipment to the wall jacks. Jumper cables are typically made with stranded conductors to allow greater flexibility. Solid conductor cable is less expensive than stranded conductor cable and also has better electrical characteristics. Building UTP wiring should always be performed with solid conductor cable.

Plenum Rated Cable – Plenum rating is a rating given to cabling with a special jacket that if burned will produce a significantly reduced amount of hazardous material in the air in the event of a fire. Plenum rated cable is much more expensive than standard “riser” cable. Before beginning a cabling project check your local building codes to verify if, and where plenum rated cables must be used.

Cross-Connect Wire – Category 3 single pair and 2-pair unjacketed wire is very inexpensive and is sold in bulk in a variety of colors. This cable is the industry standard in wire used to “cross-connect” cabling from one punch block to another. This cross-connect wire is fine for cross-connecting telecommunications circuits but should never be used for high speed data applications.

General Practices:

Following generally accepted industry standard cabling practices will not only result in a professional looking completed project, but more importantly your project will pass any possible inspections and your system will perform as expected. The following is a list of some of the most basic rules to observe when performing a UTP cabling job. This list is not in a particular order and is not listed in order of importance.

Before starting a UTP high speed data cabling project identify the cabling standard. This will be either T-568A or T-568B. Both have similar characteristics but are wired differently. If working with an existing network identify first identify which standard was used and follow the existing standard.

Always work in a safe manner following all accepted and established safety practices and standards.

Never mix T-568A and T-568B cabling within the same project or environment.

Never kink or sharply bend UTP cable. Follow manufacturer’s minimum bend radius specification.

Always use care in all UTP cable terminations.

Always use the proper, quality tools when punching or crimping UTP cables.

Always keep the wire pairs twisted tight as close to the termination block, jack or plug as possible.

Never use cable, blocks, jacks or plugs with a rating lower than the intended system throughput.

Never run UTP cables close to AC power cables, florescent lights or other sources of electrical interference.

Always use a “star” or “end run” UTP cabling design with each end point having its own cable run back to the central point, punch block, switch, router, Etc.

Never “daisy-chain” UTP cabling connecting more than one end point to a single cable.

Never use excessive force pulling UDP cable.

Never pull UDP cable forcing it against a hard edge.