A major highlight at the annual conference of the Building Industry Consulting Service International (Tampa, FL), held this past January,was a panel discussion on open-office cabling issues and the guidance being prepared by the Telecommunications Industry Association, or TIA, (Arlington, VA) to cover this vital area.
The open office is an area where there has been a gap in standards-making, according to panel moderator Jim Romlein, president of MIS Labs (Watertown, WI). Of special concern is how security can be provided for both workers and equipment located in an open-office environment. Another concern is providing the flexibility for what is known as "knowledge work," with its need for both individual privacy and collaborative work areas. A more practical concern is that two wiring schemes have been proposed for the open office at the intermediate point between the telecommunications closet and the work area; the multiuser telecommunications outlet and the consolidation point are not identical, leading to much confusion among designers and users.
George Weller of modular furniture manufacturer Steelcase Inc. (Grand Rapids, MI) belongs to the TIA group working on an open-office cabling standard. "We`re preparing a Telecommunications System Bulletin that`s into its tenth draft," he says, "and that draft is already obsolete because of the massive response we got to it. We`re now preparing draft number 11, which will take some time. Then we`ll go out for ballot again."
So many revisions have been required because open-office cabling has some particularly difficult problems associated with it. "Modular furniture is more expensive per square foot than [furniture that is] wall-built by a carpenter," Weller notes, "and any other problems associated with it are long-lasting because of its 20-year lifespan."
One such problem is cabling capacity. "Most modular-furniture systems were designed in the 1970s," says Weller, "when not as many wires were needed." Now with voice, one or more data lines, and possibly fax, modem or video going to a single cubicle, the raceways built into modular panels can become overcrowded. One solution has been retrofit kits. "There is a $6 billion installed base of modular furniture that has been put in since the 1980s," Weller adds. "Furniture that is older can be refurbished several times before it loses its utility."
The capacity problem has been complicated by bend-radius limitations on optical fiber and bend-radius and pulling-strength issues for Category 5 copper cabling. In some installations, 25-pair cables have been used to increase raceway capacity, but there is currently no standard for this multipair cable type, nor is there an approved testing specification. Separating high-voltage power cables from low-voltage telecommunications cabling has also been an issue for modular furniture.
Still another problem is trade coordination. Typically in a construction job, cabling installers pull cable to an intermediate point on a building floor and wait for furniture installers to put up modular panels. Then, the cabling installers pull cable through the raceways in the furniture splines, the furniture installers put on the top caps, the cabling installers finish the terminations, the furniture installers clean up and the cabling installers test the network. "Careful planning can solve this problem," Weller says, "but the architect often doesn`t plan for the furniture, especially when it is being refurbished rather than replaced."
The TIA open-office cabling committee intends to put some of its guidelines into the revision of the TIA pathways and spaces standard, TIA-569A. "This information has been included in Annex A of draft number 11 of our document," he says, "but we`re taking it out because it has caused some confusion." To cover wiring, Weller says his group will have to put out a TSB, because its work was not done in time for inclusion in the recently published revision of the building wiring standard, TIA-568A.