Has our industry evolved to where we need to go to the AHJ (authority having jurisdiction) for a pre-construction review of telecommunications systems? My personal opinion-No. We've been there for a long time.
Donna Ballast is BICSI's standards representative and a BICSI-registered communications distribution designer (RCDD). Ques tions can be sent to her at Cabling Installation & Maintenance, in care of Chief Editor Patrick McLaughlin: [email protected]
I have recently received several "tales of woe" from designers and installers who were at odds with electrical inspectors and fire marshals. One in particular told of an inspector in Sunrise, FL requiring that the contractor remove all of the equipment racks and cable tray, and replace them with UL-listed and labeled products. This was in a newly completed, three-building complex with 12 telecommunications rooms per building. Ouch!
It seems that if you are designing telecommunications systems in Sunrise, all equipment racks, cabinets, cable tray, ladder rack and all components used to secure or support these are now required to be listed and labeled.
This designer's saga found its way to my in-box in search of the code or standard where such a requirement is actually mandated.
Nothing in NEC 1999 Article 318, Cable Trays, or NEC 2002 Article 392, Cable Trays, or ANSI/TIA/EIA-569-A, Commercial Building Standard for Telecommunications Pathways and Spaces requires that a cable tray or equipment rack be listed.
Says who? * So, how can an electrical inspector in Sunrise FL require that only listed and labeled materials be installed? Because he is the Authority Having Jurisdiction. NEC 2002 Article 100 Definitions, defines Authority Having Jurisdiction as "The organization, office, or individual responsible for approving equipment, materials, an installation, or a procedure."
Where public safety is the primary concern, the AHJ may be a federal, state, local, or other regional department, or individual such as: a fire chief; fire marshal; chief of a fire prevention bureau, labor department, or health department; building official; electrical inspector; or others having statutory authority. For insurance purposes, an insurance inspection department, rating bureau, or other insurance company representative may be the AHJ. In many circumstances, the property owner or designated agent assumes the AHJ role; at government installations, the commanding officer or departmental official may be the AHJ.
Once empowered to enforce the Code, Article 110 (Requirements for Electrical Installations) tells them how to do so-sort of the AHJ's checklist for Code compliance.
Section 110.2, Approval, requires that equipment, which includes just about everything, be acceptable only if approved. To further complicate matters, Article 100 defines approved as "Acceptable to the authority having jurisdiction".
OK, so we are back to the "do what the AHJ says" thing again. But why listed and labeled?
Before issuing approval, the AHJ may require evidence of compliance with Section 110.3(A), Examination. While this section does not specifically require listing or labeling of equipment, it does, require "considerable evaluation of equipment," and provides a list of considerations for the AHJ to use to determine compliance. Top of the list: Suitability for installation and use. And buried in a fine print note: "Suitability of equipment may be evidenced by listing or labeling." The most common form of this evidence is a listing or labeling by a third party, like Underwriters Laboratories (UL).
Checking it twice
Article 100 defines labeled as "Equipment or materials to which has been attached a label, symbol, or other identifying mark of an organization that is acceptable to the authority having jurisdiction and concerned with product evaluation, that maintains periodic inspection of production of labeled equipment or materials, and by whose labeling the manufacturer indicates compliance with appropriate standards or performance in a specified manner."
Listed is defined as "Equipment, materials, or services included in a list published by an organization that is acceptable to the authority having jurisdiction and concerned with evaluation of products or services, that maintains periodic inspection of production of listed equipment or materials or periodic evaluation of services, and whose listing states that the equipment, material, or services either meets appropriate designated standards or has been tested and found suitable for a specified purpose."
While requiring listed and labeled components does not ensure proper installation of the materials, it does provide an AHJ with some level of confidence that your installation is Code-compliant.
Bottom line: Sit down and review your submittals with the AHJ before you Begin, and not after you complete a project.
Ironically, The American Institute of Architects MASTERSPEC (copyright1996) Section 16139 Cable Trays, Paragraph 1.4 Quality Assurance B. Listing and Labeling states "Provide cable trays and accessories specified in this Section that are listed and labeled." MASTERSPEC is software that provides the formatted text used by many architects and engineers to create project specifications.
Different pairs, same cable?
Q: My company is installing a TV distribution system and ran Cat 6 cable in order to give the customer a Panduit solution. Is it possible, from the technical perspective, to run audio and video on different twisted pairs but in the same cable?
Alejandro Rojas
Technology Integration Group/Cabling Division
San Diego, CA
A: I contacted Andrew Ciezak, with Panduit Network Systems Division. He said that Panduit does sell an RCA and S-Video connector for its plates. Good quality audio and video signals can be transmitted over UTP, he says, and an audio signal and a video signal in one cable can work. For an online catalog, see www.panduit.com.
Category 6 is a copper-cabling standard proposed by TIA TR-42.7. The proposed standard, expected to be completed by June, contains transmission performance specifications for 4-pair 100-W twisted-pair cabling. Once completed, Category 6 will be published as addendum No. 1 to TIA/EIA-568-B.2.
The objective of this work was to develop a new category of cabling for high-bandwidth applications, such as massive file downloads, video to the desk, or for "future proofing"-to the extent possible-LANs. Category 6 will support positive Power Sum Attenuation to Crosstalk (PSACR) margins up to 200 MHz. At the request of the IEEE (Institute of Electrical and Electronic Engineers) 802.3 committee, TIA agreed to characterize Category 6 cabling systems and each of their components to 250 MHz to accommodate transmission equipment designs that utilize Digital Signal Processing (DSP) techniques.
And 250 MHz is far less than the coax that the audio and video signals were originally designed to work with.