Wire and cable guys

August 11, 2010

The advent of a high-technology economy has meant a whirlwind of development on many fronts, and nowhere, perhaps, has it been more evident than in the field of local-area network (LAN) cabling. As computers seem obsolete nearly as soon as they are pulled from the box, so does cable. That is why the building team that created the Peter Kiewit Institute of Information Science, Technology & Engineering at the University of Nebraska in Omaha waited until the last possible moment to purchase and install the cable that would allow the institute to communicate within the university as well as beyond its halls of ivy.

The building is a living laboratory, with wire, cable, heating, ventilation and air-conditioning innards visible to the public.

Steven Smith, sole owner of Omaha-based cable installation subcontractor Integrated Electrical Services, now part of Omaha-based Miller Electric Co., (not to be confused with national firms based in Houston, Texas and Jacksonville, Fla.) says the team used unshielded twisted-pair copper data cable that was the fastest available at the time (see "And the category is ...,"page 66). To give an idea of how fast this copper cable is, Smith explains that the original Ethernet protocol was 10Base-T, or speeds of 10 megabytes per second, while the faster version was 100Base-T, or 100 megabytes per second. Gigabit Ethernet, or what many are calling Category 5e (enhanced) or Category 6, is 10 times faster than that, or 1,000Base-T, he says. Ethernet is a network standard of communication using either coaxial or twisted-pair cable.

Multimode-designed to carry multiple light rays over short distances-and the faster single-mode fiber-optic cable are used in the backbone, the line or set of lines that LANs use to span distances. One 62.5-micron fiber-optic single-mode cable links the building approximately 11/2 miles underground to the main campus. The entire cabling infrastructure was designed by subcontractor Lucent Technologies.

Delaying decisions

The University of Nebraska is not alone in waiting for the latest technology. For example, the First National Bank of Omaha is constructing a 40-story building, and designers are waiting until vertical risers are finished to select horizontal cabling.

"I think the biggest challenge that we saw was designing in the flexibility and adaptability to respond to academic programs" as well as accommodating developments in cable, says Kenneth P. West, project leader for Omaha-based DLR Group, the architectural and engineering firm that designed the Kiewit Institute. "It's all changing so fast," he says. "If owners have the ability to approach it from that standpoint, it really gives them the opportunity to try to be as progressive as they possibly can," he explains.

The sheer amount of the cable also was a concern. "I think there are over 250 miles of it in the building. They have enough cabling to wire up the University of Nebraska at Lincoln campus several times," says Christopher Logan, project manager with general contractor Kiewit Construction Co.

Planning essential

"They planned room for three generations of cabling, the idea being that technology changes so fast, they didn't want to cheat themselves by committing to one technology," explains Logan.

Because the building was constructed before students were enrolled in the new program, the university could not be sure how many outlets or cable drops were required. "Probably the biggest concern we had with the cable was making sure that we had the right paths for the amount of drops that they specified in the building," says Logan. The contractor also had to ascertain that all of the drops didn't bunch along one wall.

According to West, a duplicate raceway system attached to the cable tray allows two generations of cabling to run parallel to each other. Over time, the initial generation could be removed, making way for the next generation.

Time to be tidy

For this project, the building team also had unlikely concerns. One was making sure that all the wiring was neat, as the innards of the building would be on public view. This was complicated because the electrical and mechanical systems were already in place. The general contractor had to have the right paths for the number of drops and closets specified in the building. "They had to make sure that not only were they getting the right cable to the right place, but that the final project looked like a very neat arrangement. Normally, people don't care about those items, but in this facility that was one of the selling points," Logan notes.

"Students can follow a cable and see how it gets distributed to the different locations. It becomes a teaching tool," he says.

Students have an added impetus as well. The red and white colors of The Cornhuskers, the University of Nebraska's sports teams, are carried through to the wire and cable sheathing.

While cabling is an important element and a central theme of the building, electrical wiring also is used as a teaching tool. Numerous panels are installed into the distribution network to allow connection of permanent portable test equipment. A harmonic-cancellation transformer measures the performance of wave-form cancellation on the load and line sides.

While the cable installation was designed to be a learning experience for the students, it became a learning experience for the contractor as well. General contractors and subcontractors who have been used to taking care of the bricks, mortar, steel and concrete, now must incorporate card readers, specialized temperature control and other building automation devices that they may not have learned in engineering school, says Logan.

         
 

Comments on: "Wire and cable guys "