Published In September 2001
The numerous choices for managing voice/data/video cabling (VDV) installations enable electrical contractors to effectively run well-supported wiring through almost any location and under any field condition. Surface raceway Surface raceway is a secure, often aesthetically preferred way of delivering and shielding wires from the point at which they enter the surface of a wall to the termination point at a switch, receptacle, or panel box. It is also a cost-effective alternative to opening walls to bury wire or running exposed conduit along walls or partitions in a retrofit. Surface raceway is available in single- or multi-channel configurations, with fixed or removable dividers to separate low-voltage from power runs, or to keep multiple VDV runs separate. A system typically consists of raceway base, single or multiple covers that provide access to specific cable runs, fittings, and termination hardware, including in-line electrical boxes (which deplete raceway capacity) or external electrical boxes (which don’t). VDV raceway fittings feature larger, more gradually bent elbows than those used for power only, with the cables requiring less severe radii than power and voice wiring. For Category 5 and 5e: 1-inch minimum; for Category 6: 1.33-inch minimum. PVC weighs about one third of comparably sized metallic raceway and is user-friendly. PVC raceway cuts quickly with a hacksaw or chop saw and does not require follow-up deburring of cut edges. Though it’s softer than metal, it is dent-resistant because it “gives” upon most impacts. HellermannTyton nonmetallic, single-channel, one-piece latching TSR surface raceway features adhesive backing that conforms to any surface and holds the raceway in place for permanent screwing. Flexible hinges enable the raceway to tolerate numerous openings, and a self-locking cover facilitates quick re-entry. For diverse runs in one installation or where a wider raceway is required, the InfoStream’s elliptical shape helps absorb shock. Compatible with the TSR line, the raceway, offering up to four separate channels, has a hinged snap-shut cover that prevents wire and cable from falling out during installation, and offset elbows to help navigate close corners. Thomas & Betts NM 600 series Non-Metallic Surface Raceway System is a large two-compartment raceway system that incorporates fittings designed for radius bends to accommodate Category 6 and fiber optic cable. One- and two-cover versions are available for the raceway, which features rounded corners that prevent dust and direct accumulation. The dent-resistant system is well-suited for trunking systems at educational institutions and offices where large volumes of networking cable and power wiring for PCs, CCTV, satellite hookup, audiovisual needs are run along busy corridors. Panduit nonmetallic multi-channel T-70 Surface Raceway System features snap-on faceplates and fittings that maintain the 1-inch minimum bend radius needed for Category 5 and fiber optic cabling. The system cuts easily with standard saws and saw blades and is tamper resistant. The Wiremold Company recently introduced Eclipse single-compartment workstation raceway designed to be compatible with Ortronics TracJack (a front-loading, individual-jack solution) and Series II connectors and modules (a single- or two-jack modular front loading system). Both are available for Category 3, 5e, and 6 applications, and six-position USOC. They offer 45-degree-angle connectors and flush configurations. A drop-ceiling connector fits over the existing ceiling grid, eliminating cutting of the grid. Eclipse raceway also provides an open system option. Single- and two-gang boxes for National Electrical Manufacturers Association (NEMA) standard faceplates are available to accommodate proprietary discrete jacks and keystone jacks. Hubbell Premise Wiring Super BaseTrak nonmetallic surface raceway system has three channels and suits large power, data, and telecommunication cable distribution. The product is available in true in-line boxes for mounting up to three devices flush with the raceway cover and in full-capacity in-line boxes, which provide an in-line look and allow mounting of power and communication devices in the standard vertical position. Large, 11/4-inch bend radius fittings accommodate Category 5, 5e, and 6 communication cabling. Wire mesh baskets Wire mesh baskets, typically composed of 2-inch x 4-inch wire mesh and available in various combinations of widths and heights, can hold many wires while distributing weight evenly. The mesh allows continuous airflow, which prevents heat buildup and helps minimize accumulation of contaminants. Cat-Tray, a welded wire mesh cable management system from T.J. Cope, is available in nine widths and offers self-splicing bars, welded to one end of the tray, that speed connection of tray sections. For straight runs that conform to UL grounding standards, the installer bolts a special clip onto the connecting end of each bar to maintain electrical continuity. The UL label attaches to the welded end of one of the splice bars and does not require special label clips, said Clay Fox, DataCom product manager. Any time wires on the mesh basket are cut to make fittings, bonding jumpers connected with split bolts are required. For installing Cat-Tray under a raised computer floor, optional notched pedestal brackets, which come with U-bolts and nuts, permit installation of the bracket on the flat edging or the corner edge of the pedestal legs. Chalfant wire mesh VersaTray features rolled-over safety top edges on the cross-bracing wires and double wires on the top edging, for greater load strength. The system uses snap-on splice plates, two per section, for joining straight sections of trays and field fabricated fittings made from standard wire mesh straight sections, which can be made with a standard 18-inch bolt cutter and a wrench locked together with “T” bolt fasteners. The line is available in seven widths from 2 to 24 inches with a 3-inch loading depth. The OBO Bettermann wire mesh cable tray system is available in 2- and 4-inch loading depth with widths ranging from 2 to 4 inches. Standard finishes include zinc-electroplated, stainless steel, hot dip galvanized, and powder coated. The wire mesh product meets all standards for UL grounding classifications. It also offers flexible mounting options. Snake Canyon, by CMS, is a modular cable tray system for use under new or existing computer room raised floors. Fixed wire baskets with 41/2-inch grids provide a drop-in raceway while the basket frame itself serves as the two stringer runs, making separate components between the pedestals unnecessary parts of the floor support. The design allows installers to build the floor and the cable tray system simultaneously. Snake Canyon is also available as Half Section baskets for situations where the underfloor area is shared with chiller air conditioning systems, air handling, fire suppressants, and electrical services. For attaching snake tray to existing stringers or under equipment where adjacent tiles cannot be removed, CAM Connection Snake Canyon attaches with a spring-loaded twist cam to any open bottom box stringer with a hex key or wrench. GS Metals Flextray cable management system is a wire-basket-style cable tray system with specialized proprietary installation tools. A pneumatic CleanShear AirCutter facilitates cutting of wires for bending into any radius and attaining a finished edge. Electricians can use either Heliflex connectors that twist around wires at splice points or Flexmate connectors, installed with a crimping tool. The system also features toolless connectors to hold Flextray to mounting surfaces, as hold-downs with center hangers, or for use with “L” brackets. Brackets for installing Flextray under computer floors, and ceiling rod anchors for hosting threaded rods in wood, steel, or concrete ceilings are also available. A Flextray Extension Pole eliminates the need for scaffolding during installation. Single- and two-rail cable tray Single-rail cable tray has rungs either on one or both sides of a single support. The open design system offers maximum, essentially unimpeded, freedom for cable lay-in or removal. With rungs on either side, it is hung from the ceiling; with rungs on only one side, it can be wall mounted. The rungs are commonly attached either along the top or bottom of the center spine. The 2002 National Electrical Code (NEC) now permits cable tray for use as a support system for all types of circuits, and recognizes solid bottom cable channel as an option. Also, Section 318-3-1 states that, where cables in tray are exposed to direct sunlight, they shall be identified as sunlight resistant for all occupancies. Featuring an extruded web that runs the length of the rung to prevent bending and deflection, MP Husky single-rail Centray comes factory assembled in top rung, bottom rung, dual-width rung, and wall rack configurations. The rungs are chamfered, eliminating need for end caps. The high-strength aluminum system features a wrap-around EZ-Clip coupling method for attaching sections. Cooper B-Line Redi-Rail two-side rail aluminum cabling support system features ladder type, solid -and vented-bottom straight sections, I-beam-shaped rungs, and continuously pre-punched side rails. The pre-punched side rails serve as splice connection holes during installation, as alternate holes for repositioning of screw-in/screw out rungs, and as locations for easy attachment of accessory items requiring 1/4-inch hardware or smaller, such as hanger rod clamps, bonding jumpers, and branch cable systems. For splicing two lengths, Redi-Rail Flex Connectors allow adjustment vertically (up to 15 degrees) and horizontally (up to 90 degrees). Screw-in Rail-Risers increase fill depth by 2 inches. Preformed horizontal and vertical fittings facilitate change of direction or accommodate bends. Trough Cablofil EZ trough is a lightweight, hot-dipped, galvanized steel trough, available in slotted and solid wall products. It offers covers and various snap-on connectors, bolt-on corner splices, and adjustable hinge brackets, and a full complement of prefabricated junctions, crosses, 90-degree bends, 45-degree bends, tees, and convex and concave level changes. Installers can also make level changes from straight sections at the job site by trimming the sidewalls and bending the trough up or down. Other cable support systems Other wide base supports for high-performance cables include J-hooks and cradle supports. Hilti UL-tested plenum-rated X-ECH and ECH Cable Holders, available in three sizes, can be installed, without pre-drilling, either with anchors or with the Hilti DX fastening system that shoots a prefitted nail into steel or concrete. For locations up to 15 feet, installers can use an optional modular pole tool attached to the DX A40 ECH, precluding need for a ladder. The largest model, designed for 100-pound loads and with a support capacity of 50 Category 5 cables, has self-locking closure and an offset shape for easy accessibility and self-regulating cable positioning. The medium and small cable holders, designed for up to 40-pound loads, have capacities up to 22 (1/4-inch diameter) cables and 37 (1/4-inch diameter) cables, respectively. To handle expansion, the small holders interlock with each other and to medium holders. Erico offers the Caddy CATHBA angled hanger bracket, which creates modular, vertical systems with Caddy CableCat J-hooks. Reinforcing ribs that fit the profile of three different-sized J-hooks provide support and eliminate rocking. The bracket, which comes with pre-drilled holes for direct attachment to a ceiling deck or, with structure fasteners, to beams, can hold up to six 2-inch J-hooks and support up to 480 cables in one assembly. Caddy AFAB Series angle brackets provide stability when installing J-hooks to threaded rod or directly to the structure. Side tabs help stabilize the J-hooks after installation. One possible configuration involves assembling two brackets into a 90-degree angle, which guides the cable around a corner while maintaining the bend radius necessary for high-performance cable, noted Dan Johnson, technical manager, fastening products. Arlington Industries’ The Loop flexible nonmetallic hanger for communications cable holds up to a 5-inch diameter bundle of Category 5 or fiber optic cable without sagging, bending or damaging the cable. The loop is available in 2-inch, 21/2-inch, and 5-inch widths, with or without plenum rating. The mounting clamp fastens horizontally or vertically to a beam. With an additional rod running from the clamp, one loop can hang, stacked above the other, to accommodate two separate bundles of cable. Mono Systems, Inc. recently introduced Mono-Rack, which provides wide-open flexibility for communication and telephone cable installations. Featuring various stringer and rung configurations, the steel system mounts easily on a racking system installed below a dropped ceiling in a computer room. The cables run along the top of the racks and drop into hubs where required. THE FELDMANS provide Web content for companies and write for magazines, trade associations, building product manufacturers, and other companies on a broad range of topics. They can be reached at email@example.com or (914) 238-6272.