Cable System and Infrastructure Constraints

Where Do Codes Come From?

Building, construction, and communications codes originate from a number of sources. Usually, these codes originate nationally rather than at the local, city, or county level. Local municipalities usually adopt these national codes as local laws. Other national codes are issued that affect the construction of electrical and communications equipment.

Two of the predominant national code governing bodies in the United States are the Federal Communications Commission (FCC) and the National Fire Protection Association (NFPA). The Americans with Disabilities Act (ADA) also affects the construction of cabling and communications facilities because it requires that facilities be constructed to provide universal access.

The Federal Communications Commission

The United States Federal Communications Commission (FCC) issues guidelines that govern the installation of telecommunications cabling and the design of communications devices built or used in the United States. The guidelines help prevent problems relating to communications equipment, including interference with the operation of other communications equipment. Part 68 of the FCC rules provides regulations that specifically address connecting premises cabling and customer-provided equipment to the regulated networks.

The FCC also publishes numerous reports and orders that deal with specific issues regarding communications cabling, electromagnetic emissions, and frequency bandwidths. The following is a list of some of the important documents issued by the FCC:

Part 68 of the FCC rules Governs the connection of premises equipment and wiring to the national network.

Telecommunications Act of 1996 Establishes new rules for provisioning and additional competition in telecommunications services.

CC Docket No. 81-216 Establishes rules for providing customer-owned premises wiring.

CC Docket No. 85-229 Includes the Computer Inquiry III review of the regulatory framework for competition in telecommunications.

Part 15 of the FCC rules Addresses electromagnetic radiation of equipment and cables.

CC Docket No. 87-124 Addresses implementing the ADA.

CC Docket No. 88-57 Defines the location of the demarcation point on a customer premise.

Fact Sheet ICB-FC-011 Deals with connection of one- and two-line terminal equipment to the telephone network and the installation of premises wiring.

Memorandum Opinion and Order FCC 85-343 Covers the rights of users to access embedded complex wire on customer premises.

Tip

Most of the FCC rules, orders, and reports can be viewed on the FCC website at www.fcc.gov. Since rules can change over time, it's wise to monitor updates.

The National Fire Protection Association

In 1897, a group of industry professionals (insurance, electrical, architectural, and other allied interests) formed the National Association of Fire Engineers with the purpose of writing and publishing the first guidelines for the safe installation of electrical systems and providing guidance to protect people, property, and the environment from fire. The guidelines are called the National Electrical Code (NEC). Until 1911, the group continued to meet and update the NEC. The National Fire Protection Association (NFPA), an international, nonprofit, membership organization representing over 65,000 members and 100 countries, now sponsors the NEC. The NFPA continues to publish the NEC as well as other recommendations for a variety of safety concerns.

The NEC is updated by various committees and code-making panels, each responsible for specific articles in the code.

Tip

You can find information about NFPA and many of its codes and standards at www.nfpa.org. You can purchase NFPA codes through Global Engineering Documents (http://global.ihs.com); major codes, such as the National Electrical Code, can be purchased at most bookstores.

The NEC is called NFPA 70 by the National Fire Protection Association, which also sponsors more than 600 other fire codes and standards that are used in the United States and throughout the world. The following are some examples of these documents:

NFPA 1 (Fire Prevention Code) Addresses basic fire-prevention requirements to protect buildings from hazards created by fire and explosion.

NFPA 13 (Installation of Sprinkler Systems) Addresses proper design and installation of sprinkler systems for all types of fires.

NFPA 54 (National Fuel Gas Code) Provides safety requirements for fuel-gas equipment installations, piping, and venting.

NFPA 70 (National Electrical Code) Deals with proper installation of electrical systems and equipment.

NFPA 70B (Recommended Practice for Electrical Equipment Maintenance) Provides guidelines for maintenance and inspection of electrical equipment such as batteries.

NFPA 70E (Standard for Electrical Safety in the Workplace) A basis for evaluating and providing electrical safety–related installation requirements, maintenance requirements, requirements for special equipment, and work practices. This document is compatible with OSHA (Occupational Safety and Health Administration) requirements.

NFPA 72 (National Fire Alarm Code) Provides a guide to the design, installation, testing, use, and maintenance of fire-alarm systems.

NFPA 75 (Standard for the Protection of Information Technology Equipment) Establishes requirements for computer room installations that require fire protection.

NFPA 101 (Life Safety Code) Deals with minimum building design, construction, operation, and maintenance requirements needed to protect building occupants from fire.

NFPA 262 (Standard Method of Test for Flame Travel and Smoke of Wires and Cables for Use in Air-Handling Spaces) Describes techniques for testing visible smoke and fire-spreading characteristics of wires and cables.

NFPA 780 (Standard for the Installation of Lightning Protection Systems) Establishes guidelines for protection of buildings, people, and special structures from lightning strikes.

NFPA 1221 (Standard for the Installation, Maintenance, and Use of Emergency Services Communications System) Provides guidance for fire service communications systems used for emergency notification. This guide incorporates NFPA 297 (Guide on Principles and Practices for Communications Systems).

These codes are updated every few years; the NEC, for example, is updated every three years. It was updated in 2008 and will be updated again in 2011.

You can purchase guides to the NEC that make the code easier for the layperson to understand. Like the NEC, these guides may be purchased at almost any technical or large bookstore. You can also purchase the NEC online from the NFPA's excellent website at www.nfpa.org.

If you are responsible for the design of a telecommunications infrastructure, a solid understanding of the NEC is essential. Otherwise, your installation may run into all sorts of red tape from your local municipality.

Underwriters Laboratories

Underwriters Laboratories, Inc. (UL) is a nonprofit product safety testing and certification organization. Once an electrical product has been tested, UL allows the manufacturer to place the UL listing mark on the product or product packaging.

KEY TERM: UL listed or UL recognized

The UL mark identifies whether a product is UL listed or UL recognized. If a product carries the UL Listing Mark (UL in a circle) followed by the word LISTED, an alphanumeric control number, and the product name, it means that the complete (all components) product has been tested against the UL's nationally recognized safety standards and found to be reasonably free of electrical shock risk, fire risk, and other related hazards. If a product carries the UL Recognized Component Mark (the symbol looks like a backward R and J), it means that individual components may have been tested but not the complete product. This mark may also indicate that testing or evaluation of all the components is incomplete.

You may find a number of different UL marks on a product listed by the UL (all UL listing marks contain UL inside a circle). Some of these include:

UL The most common of the UL marks, this mark indicates that samples of the complete product have met UL's safety requirements.

C-UL This UL mark is applied to products that have been tested (by Underwriters Laboratories) according to Canadian safety requirements and can be sold in the Canadian market.

C-UL-US This is a relatively new listing mark that indicates compliance with both Canadian and U.S. requirements.

UL-Classified This mark indicates that the product has been evaluated for a limited range of hazards or is suitable for use under limited or special conditions. Specialized equipment such as firefighting gear, industrial trucks, and other industrial equipment carry this mark.

C-UL-Classified This is the classification marking for products that the UL has evaluated for specific hazards or properties, according to Canadian standards.

C-UL-Classified-US Products with this classification marking meet the classified compliance standards for both the United States and Canada.

Recognized Component Mark (backward R and J) Products with the backward R and J have been evaluated by the UL but are designed to be part of a larger system. Examples are the power supply, circuit board, disk drives, CD-ROM drive, and other components of a computer. The Canadian designator (a C preceding the Recognized Component Mark) is the Canadian equivalent.

C-Recognized Component-US The marking indicates a component certified by the UL according to both the U.S. and Canadian requirements.

International EMC mark The electromagnetic compatibility mark indicates that the product meets the electromagnetic requirements for Europe, the United States, Japan, and Australia (or any combination of the four). In the United States, this mark is required for some products, including radios, microwaves, medical equipment, and radio-controlled equipment.

Other marks on equipment include the Food Service Product Certification mark, the Field Evaluated Product mark, the Facility Registration mark, and the Marine UL mark.

Tip

To see examples of the UL marks we've described, visit www.ul.com.

The NEC requires that Nationally Recognized Test Laboratories (NRTL) rate communications cables used in commercial and residential products as "listed for the purpose." Usually UL is used to provide listing services, but the NEC only requires that the listing be done by an NRTL; other laboratories, therefore, can provide the same services. One such alternate testing laboratory is Intertek ETL SEMKO (www.usa.intertek-etlsemko.com).

More than 750 UL standards and standard safety tests exist; some of the ones used for evaluating cabling-related products are:

UL 444 Applies to testing multiple conductors, jacketed cables, single or multiple coaxial cables, and optical fiber cables. This test applies to communications cables intended to be used in accordance with the NEC Article 800 or the Canadian Electrical Code (Part I) Section 60.

NFPA 262 (formerly UL 910) Applies to testing the flame spread and smoke density (visible smoke) for electrical and optical fiber cables used in spaces that handle environmental air (that's a fancy way to say the plenum). This test does not investigate the level of toxic or corrosive elements in the smoke produced, nor does it cover cable construction or electrical performance. NEC Article 800 specifies that cables that have passed this test can carry the NEC flame rating designation CMP (communications multipurpose plenum).

UL 1581 Applies to testing flame-spread properties of a cable designed for general-purpose or limited use. This standard contains details of the conductors, insulation, jackets, and coverings, as well as the methods for testing preparation. The measurement and calculation specifications given in UL 1581 are used in UL 44 (Standards for the Thermoset-Insulated Wires and Cables), UL 83 (Thermoplastic-Insulated Wires and Cables), UL 62 (the Standard for Safety of Flexible Cord), and UL 854 (Service-Entrance Cables). NEC Article 800 specifies that cables that have passed these tests can carry the NEC flame-rating designation CMG, CM, or CMX (all of which mean communications general-purpose cable).

UL 1666 Applies to testing flame-propagation height for electrical and optical fiber cables installed in vertical shafts (the riser). This test only makes sure that flames will not spread from one floor to another. It does not test for visible smoke, toxicity, or corrosiveness of the products' combustion. It does not evaluate the construction for any cable or the cable's electrical performance. NEC Article 800 specifies that cables that have passed this test may carry a designation of CMR (communications riser).

UL has an excellent website that has summaries of all the UL standards and provides access to its newsletters. The main UL website is www.ul.com; a separate website for the UL Standards Department is located at http://ulstandardsinfonet.ul.com. UL standards may be purchased through IHS/Global at http://global.ihs.com.

Codes and the Law

At the state level in the United States, many public utility/service commissions issue their own rules governing the installation of cabling and equipment in public buildings. States also monitor tariffs on the state's service providers.

At the local level, the state, county, city, or other authoritative jurisdiction issues codes. Most local governments issue their own codes that must be adhered to when installing communications cabling or devices in the jurisdictions under their authority. Usually, the NEC is the basis for electrical codes, but often the local code will be stricter.

Over whom the jurisdiction has authority must be determined prior to any work being initiated. Most localities have a code office, a fire marshal, or a permitting office that must be consulted.

The strictness of the local codes will vary from location to location and often reflects a particular geographic region's potential for or experience with a disaster. For example:

• Some localities in California have strict earthquake codes regarding how equipment and racks must be attached to buildings.
• In Chicago, some localities require that all cables be installed in metal conduits so that cables will not catch fire easily. This is also to help prevent flame spread that some cables may cause.
• Las Vegas has strict fire-containment codes that require firestopping of openings between floors and firewalls. These openings may be used for running horizontal or backbone cabling.

Warning

Local codes take precedence over all other installation guidelines. Ignorance of local codes could result in fines, having to reinstall all components, or the inability to obtain a Certificate of Occupancy.

Localities may adopt any version of the NEC or write their own codes. Don't assume that a specific city, county, or state has adopted the NEC word for word. Contact the local building codes, construction, or building permits department to be sure that what you are doing is legal.

Historically, telecommunications cable installations were not subject to local codes or inspections. However, during several commercial building fires, the communications cables burned and produced toxic smoke and fumes, and the smoke obscured the building's exit points. This contributed to deaths. When the smoke mixed with the water vapor, hydrochloric acid was produced, resulting in significant property damage. Because of these fires, most JHAs now issue permits and perform inspections of the communications cabling.

It is impossible to completely eliminate toxic elements in smoke. Corrosive elements, although certainly harmful to people, are more a hazard to electronic equipment and other building facilities. The NEC flame ratings for communications cables are designed to limit the spread of the fire and, in the case of plenum cables, the production of visible smoke that could obscure exits. The strategy is to allow sufficient time for people to exit the building and to minimize potential property damage. By specifying acceptable limits of toxic or corrosive elements in the smoke and fumes, NFPA is not trying to make the burning cables "safe." Note, however, that there are exceptions to the previous statement, notably cables used in transportation tunnels, where egress points are limited.

Tip

If a municipal building inspector inspects your cabling installation and denies you a permit (such as a Certificate of Occupancy), he or she must tell you exactly which codes you are not in compliance with.