Q: We have a conduit that runs between two buildings. Inside the conduit, we have Category 5 (shielded) cable. The conduit collects moisture and we are worried about our cables. I was told that a weatherproof Category 5 cable is available and is used to connect schools with outside trailer locations. What is this type of cable called, and can you recommend a solution?
Jan Starai
Vienna Presbyterian Church
Vienna, VA
A: Yes, there is an outdoor version of Category 5 cable. You are looking for enhanced-performance outside-plant cable, also called broadband outside-plant cable. For a filled cable, specify a cable that meets the icea s-99-689 standard. If your particular site requires protected building entrance terminals (one on each end of the cable), specify those that meet the primary protection requirements of UL-497, the reliability requirements of tia/eia-568a subclauses 10.4.3.1 and 10.4.3.5, and the Category 5 transmission requirements of subclause 10.4.4.
A word of caution: Category 5 is a channel-performance specification of 100 megahertz at 100 meters. Almost everyone remembers the rule inside buildings, but some tend to forget that the length constraint also applies between buildings.
I recommend that you install an all-dielectric optical-fiber cable that meets icea 83-640 and tia/eia-568a. This solution may sound expensive, but if you compare the cost of a solution using Category 5 with protected building entrance terminals against the cost of a fiber solution, the numbers will surprise you.
Donna Ballast is a communications analyst at the University of Texas at Austin and a bicsi registered communications distribution designer (rcdd). Questions can be sent to her at Cabling Installation & Maintenance or at
PO Drawer 7580,
The University of Texas, Austin, TX 78713;
tel: (512) 471-0112, fax: (512) 471-8883,
e-mail: [email protected].
