Published In December 2000
This column’s title is probably the most commonly used phrase in Requests for Quote or Bid. Therefore, it is appropriate to understand what, “The cabling system shall be in accordance with TIA/EIA-568-B.1” means and does not mean relative to the bidding process. First, TIA/EIA-568-B.1 does not carry the enforcement of law, such as building codes and the National Electrical Code (NEC). However, once it is referenced in the bid specification, it becomes part of your contract with the customer and can be used to determine if you get paid or not. The first item to understand is the lingo of “shall” and “should.” Two categories of criteria are specified in the standard: mandatory and advisory. Mandatory requirements are designated by the word “shall”; advisory requirements are designated by the words “should,” “may,” or “desirable,” which are used interchangeably. To be in compliance with the standard, all “shall” statements are required to be followed, while all “should” statements are merely recommended. The same holds true for Annexes in that “Normative Annexes” shall be followed, whereas “Informative Annexes” may not be. Shalls After doing a search on “shall” and “should,” I listed the high points and those that are often misunderstood. I listed the “shalls” first, because you shall do them to get paid. n The big one is that the components (cable, connectors, connecting hardware, and all jumpers, patch cords, equipment cords, and work area cords) shall meet the requirements of TIA/EIA-568-B.2 for copper and TIA/EIA-568-B.3. You need to have proper documentation from your supplier that they indeed meet or exceed these requirements. * Pathways and spaces shall be in accordance with TIA/EIA-569-A and telecommunications bonding and grounding shall be in accordance with TIA/EIA-607. * No splices shall be in the horizontal. * Horizontal cabling shall be no greater than 90 meters (295 feet). * A minimum of two outlets shall be installed per work area. This does not mean two faceplates are necessary, but that there are two ports and corresponding cables per work area. * Each four-pair copper horizontal cable shall be terminated into an eight-position jack at the work area. The eight-position jack is widely believed to be a requirement at the cross-connect or patch panel, but the only place it is required is in the work area. * Each horizontal fiber cable in the work area shall be terminated with a duplex connector. This is a significant change in that the duplex SC (568SC) previously was the requirement not only at the outlet, but also throughout the network. This is no longer the case. * The fiber cabling shall be terminated to manage polarity (A to B and B to A). This was described in last month’s article. * An entirely new clause has been added called “Cabling Installation Requirements.” Listed below are some of the new “shall” requirements. * Cable and components shall be visibly inspected for proper installation, (i.e., look at it). * The minimum bend radius of four-pair UTP cable under no-load conditions shall be no less than four times the cable diameter. Unfortunately, the standard does not provide a bend radius for under load, e.g., while you are pulling it. * The maximum pulling tension of a four-pair UTP cable shall not exceed 25 pounds. * Cable pair twists shall be maintained to within 1/2-inch for Category 5e and to within three inches for Category 3. Often, it is believed that you can only remove 1/2-inch of jacket, but this is not true. The standard actually states only as much as necessary and to follow manufacturers instructions. * One new “shall” requirement that you probably have violated is that jumper wire shall not be made in the field by removing the jacket from a jacketed cable. In other words, throw away the shorts and buy factory-made jumper wire. * For horizontal two- and four-fiber optic cable, the minimum bend radius is 1 inch under no-load and 2 inches under tension. The maximum pulling tension is 50 pounds for horizontal cables. Shoulds Here are some “shoulds” that you don’t have to follow, but should: * The big one is really not a “should,” but should be considered as such because it is not stated at all in the standard, neither in TIA/EIA-568-A nor in B.1. Field-testing per the standard is not required. Specifications are in the standard describing how and what, and performance levels for both copper and fiber testing if you do it, but nothing requires it be done. Of course, a modification of the simple statement takes care of this. “The cabling system shall be in accordance with and tested to TIA/EIA-568-B.1.” * A telecommunications room should be installed on each floor. It’s a good practice, but not a required one. * The 568SC (duplex SC) should continue to be considered. (That took all of two seconds; now you shall consider one of the new small-form factor connectors.) * Cable ties should be loosely installed and should not deform the cable sheath. This is a good example of where a “shall” should have been used, except the committee did not want to make a requirement out of a measurement. (“Loosely” and “deform” could not be defined or measured.) * Patch cords should not be field terminated. This is another very good practice, especially for Category 5e and fiber, not to mention that it’s economical. * The two work area outlets may be voice and data. I am not certain if that means VDV can actually be voice/voice/video (VVV) or data/data/video (DDV). In closing, the question that haunts all standards and bids: “Which revision?” According to TIA, “All standards are subject to revision; parties to agreements based on this Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated.” So, if the customer does not state otherwise, follow the referenced revision. However, TIA/EIA-568-B.1 has a special clause relative to B.2 (copper) and B.3 (fiber): “Each of the three standards may be reviewed and updated independently. The latest revision of each respective standard takes precedence over its previous edition.” So in the future, if the B.3 standard is revised to C.3 before B.1 is revised, then by requiring the cabling system to be in compliance with B.1, the fiber components must meet the C.3 revision. BEAM is director of systems marketing at AMP NETCONNECT Systems. He can be reached at (336) 727-5784 or email@example.com.