home

our services

our staff

our clients

our suppliers

freebies

home wiring

contact us

An Electrical Contractor's Guide to: COMMUNICATIONS WIRING FOR TODAY'S HOMES -Simple Low Cost Comprehensive (CDA Copyrighted)

Phone wiring isn't just for phones anymore.  Ordinary telephone wiring can't handle today's rapidly expanding communications needs.

Today's homeowners expect their homes to accommodate:

• Multiple phone lines
• Internet service
• Video distribution, and other entertainment services
• Data and security services
• Fax machines
• And a list goes on.

Faster and more reliable than ordinary phone wiring, low-cost, high-tech copper wiring(CA T 5or better) should be installed to every room in the modern home.  It's what is needed to carry voice, data and entertainment services from where they enter the house to every room, and from any one room, and from any one room to any other.

This guide gives the basics on wiring homes for the rapidly evolving information age-and today's homeowners demand it.  If you don't offer this service, rest assured, your competitors will.

WHY NOW?

Today, unshielded twisted pair, or UTP, copper information wiring is used for offices, schools and factories to provide local area networks (LANs) allowing computers to talk to one another and to receive and send internet and high-speed computer data outside the facility.  Category 5 ("CAT 5") is the current standard, but will soon be supplanted by even higher-speed versions, known as Levels 6 and 7. (Level 7 has more than twice the bandwidth, or information-carrying capacity, of CAT 5 at a small cost premium.)

Right now, the typical home doesn't require the capacity to move computer signals around as fast as the typical office.  However, offices get extensively remodeled, and rewired, every few years.  Homes do not.  The wiring you install must serve indefinitely.

The phone wiring of the past, often referred to as "Quad" wiring because it has four copper wires, is now obsolete.  CAT 5 or higher speed wiring has four twisted wire pairs, or eight wires.  All are needed to provide the multiple services discussed in this document.

COPPER UTP WIRING, What is it ?

Copper UTP wiring contains eight color-coded conductors(four twisted pairs of copper wires).  It offers greatly increases bandwidth, or information-carrying capacity, compares with old-fashioned quad wiring.

The cable is small(roughly 3/16 inch in diameter), inexpensive and easy to pull, although it must be handled with care.

Advantages.  Modern copper UTP wiring offers the following advantages:

1. Diversity.  Cable TV and other entertainment signals, internet and computer communications, as well as ordinary phone signals-all can be carried throughout the home on modern, inexpensive, high-speed, UTP cables. (to service a large number of TV channels, it may be desirable to also run coaxial cable such as all copper RG-6 cable).
2. More phone numbers.  Several phone numbers can be made available throughout the house.  Actually, voice service requires very little bandwidth, and the addition of separate numbers is almost trivial.
3. Bandwidth.  CAT 5 has a bandwidth of 80 MHz (megahertz), while level 6 accommodates 100 MHz and level 7 handles up to 180 MHz, when tested under stringent conditions.  Bandwidth correlates with speed, and these bandwidths are many orders of magnitude greater than the bandwidth required for a "modern 56 KBPS (kilobits per second) modem.  Level 7 wiring, with encoding, will be able to carry at least 1 gigabit (billion bits) per second.  If you're counting, that's about 500,000 pages of text per second.
4. New Services.  The internet will soon be available at high speed to many homes, but homeowners won't be able to take advantage of it if their wiring is inadequate.  One high-capacity technology now being offered by local phone companies is XDSL (digital subscriber line).  And cable modems are being offered by cable TV companies that bring in the Internet on the same coaxial cable carrying the TV signals.  Will these signals reach a dead end in the homes you wire?  Will the information highway end in a cow path?
5. Reliability.  Interference on telecommunications lines can result in scrambled faxes, interrupted on-line sessions and distorted video an audio signals.  High-tech twisted-pair copper wiring is designed to resist interference from sources in the home such as micro-wave ovens, vacuum cleaners, fluorescent lights, power tools, other appliances and external communications signals.  The tight, accurate twist of the wire pairs and their balanced mode of transmission are the reasons.
6. Approved.  Performance of these cables is certified by Underwriters Laboratories (UL), the international product testing agency, as well as by such industry leaders as Anixter.

LET'S GET SPECIFIC

When installing telecommunications wiring in residences, follow these four simple principles to provide homeowners with the most modern, flexible voice and data services:

Here's why:

• Use CAT 5, or better, UTP cabling.  Most of the reasons have been mentioned: ability to move large quantities of data around the house; ability to move TV signals from the point of entrance to anywhere and everywhere else in the house (using a readily available adapter); ability to move other signal-level entertainment to as many locations as desired; and of course phone, fax and computer/printer connections wherever desired.
• Wire Every Room.   Since the electrical contractor can only guess at the future uses of the various rooms of a house when he wires it, it's best to provide outlets virtually everywhere.  For instance, the kitchen is often the business center of a household, and thus needs both video and phone/data jacks.
• Use a Star Wiring Pattern.  with star wiring, each outlet(jack) has its own individual "home run" of cabling extending back to a central distribution device.  There are two major advantages to this:  1. Flexibility - all changes in distribution of services(TV, Data, Voice, etc.) take place at the distribution device.  Each outlet can be treated independently form all others.  (in loop wiring, that is where a number of outlets are tied together in series, outlets cannot be treated independently.); and 2. Isolation of Problems - when and interruption takes place (nail through a wall and into a cable, etc.) only that outlet is affected.  Having an extra outlet or two in some rooms, particularly home offices, is a wise move, since you can't anticipate how furniture will be arranged in the future.  This should be accomplished with home runs to the additional outlets.  Most seasoned professionals strongly recommend running ''extra wire'' to any location where it might be needed later.  For example, three cables might be run to each outlet, rather than two, to provide an inexpensive safety factor.  Video signals should be run on a separate cable run.  Level 7 wiring(or perhaps coax if more than 80 or so channels must be provided) is recommended for them.  Other services, such as phone, fax, Internet and other computer connections from the outside, can be accommodated on a CAT 5 cable to each room.  To future-proof your homes for only a small additional cost, consider running Level 7 all the way, but particularly for an area that might be used as a home office.
• Use 8-Pin Modular Jacks (RJ-45).  This device provides connection points for all eight of the wires contained in the four twisted pairs.

Proper Installation is Crucial.   A contractor needs to know communications wiring and how to install it according to strict guidelines, e.g., how much pull can be applied to a cable (usually 25 pounds, but recent information suggests that as much as 40 pounds may be allowable); how much separation is needed between data and power cables(2 inches at least, crossing at 90 degrees, if necessary); how far back the cable sheathing can be stripped (no further than necessary, typically 1 1/4 inches); how much untwisting of the pairs can be done when making connections (1/2 inch is usually the maximum recommended. 3/8 inch is better); how tight a bend radius can be tolerated (usually about 1 inch, although some designs are less sensitive than others); etc.  More details on installation practices will soon be available in a separate CDA publication.

Important:  All connecting devices - central distribution device, plugs on the ends of cables, outlets, etc.  - should be rated for the cable used.  For instance, if  CAT 5 cable is used, all devices must be at least CAT 5 rated.  if Level 7 cable is used, all devices should be similarly rated.

Video Cables.  Although industry is working toward an all-UTP solution for wiring residences, at this time it may be prudent to also include conventional coaxial cable for video distribution, particularly cable TV.  This is because it is difficult to predict whether many channels-well over 100, for example- may become a reality in the near future, some channels of which will be the more bandwidth consuming high-definition television (HDTV).  (It is known that Level 7 UTP can handle 77 channels over a distance of 300+ feet, and even more channels for the shorter distances typically found in a home.)   If coax is installed, quad-shielded RG-6 coax, with an all-copper (not copper-plated) center conductor, should be used for superior performance.  A lesser grade, RG-59, should not be used.

IN CONCLUSION

Now is the time to start differentiating the homes you wire from those of your competitors, by wiring them for the information Age.   High-Level UTP wiring to every room is a clear sales advantage at minimum cost to the homeowner.

for more information go to :   http://www.copper.org

[back to top]