Structured Wiring Systems - 11/22/2004 - House Systems Electrical

Structured Wiring Systems

Available option to meet networking needs of homeowners.

This may seem like a history lesson now, but before internet networking, residential homes had only two principle wiring systems; the electrical service and the phone service. Despite their limitations, phone lines were the only means available for computer networking and were utilized for data transmission. Today, more options are available to meet networking needs of consumers.

In July of 2000, the Federal Communications Commission (FCC) changed the minimum requirements for telephone wiring in new construction. Wiring cables are classified by categories according to use and capacity as determined by the Electric Industries Association (EIA) and the Telecommunication Industry Association (TIA). These associations have also developed standards for cabling. Category 3 wire was chosen by FCC as the minimum standard.

However, many consumers have stronger networking needs. They may want to transfer more data faster, interconnect computer system components, remotely control home security or HVAC systems, or perhaps increase their video entertainment capabilities.

Structured wiring systems have become increasingly popular to meet those consumer demands. These systems often use a Category 5 (or better) cable for voice and data and RG6 coaxial cable for video. Fiber optic cable is also available, but many regard the installation as more difficult and expensive.

Wiring installed in the home may not be the limiting factor in terms of data transfer. While utility and cable companies are constantly upgrading their systems, not all areas of the country may offer high speed internet. Because changing the wiring system in a home after initial construction may be difficult and expensive, planning ahead and installing a better system may be a wise choice.

Additional products exist on the market which allow computer users to bypass the need to hardwire a home network. Wireless routers, costing less than $100, may seamlessly communicate with computers, printers and other components.

Not Applicable

Not Applicable

The cables are classified by categories according to use and capacity as determined by the Electric Industries Association (EIA) and the Telecommunication Industry Association (TIA). These associations formed networking standard EIA/TIA 570-B, "Residential Telecommunications Cabling Standard" and standard EIA/TIA 568-B "Commercial Building Telecommunications Cabling Standard". Standards are voluntary guidelines and should not be confused with building codes. A standard may become required practice for the builder if required by the project specification or by the building code, however.

In addition to these standards, the International Residential Code (IRC) will apply to some cable installations, as described in Chapter 42, "Class 2 Remote-Control, Signaling, and Power-Limited Circuits".

Not Applicable

In residential wiring, telephone wire is often installed as a two wire pair, although the cable may be manufactured in a variety of combinations. Category 3 and Category 5 cables are commonly installed in a 4 pair configuration, although it may be purchased in a number of grouping pairs. However, the major difference between the wiring classes is the frequency which the wire is capable of transmitting, rated in units of mega-hertz (MHz), often referred to as bandwidth. Category 3 cable is rated up to 16 MHz, while Category 5 has a higher capacity rating of 100 MHz.

Structured wiring systems often use a home run wire configuration. This means that wires connected to each jack run to a central location, without connecting to another input jack. This allows each cable to operate independently without interference. A router can then be installed at the central location to control data traffic to each of the independent lines.

Warranties vary by manufacturer, generally lasting up to 20 years.

The higher the Category of wire, the more it will cost. However, material costs may not be the major cost component for a particular structured wiring installation. In many applications, the marginal cost to run a higher capacity data cable and video cable may be relatively small, making Category 5 (or higher) cable a better choice than a lower rated cable.

For rough estimates in 2005, a 1,000 ft spool of Category 5 wire will cost about $65, Category 3 wire will cost about $40, and standard phone wire will be around $25. The installed cost of a relatively basic structured wiring system will be in the $400-$500 range. Obviously, the installed cost will vary greatly depending on the number, type, and location of connection devices and services.