Choosing the right management system for voice/data/video (VDV) cabling is driven by a variety of factors, including local codes and standards, personal taste, cost constraints and performance.
Choices for VDV cable management systems include:
• Perimeter systems that route wiring and cabling securely along walls so cabling remains easily accessible at all times;
• In-floor systems, such as underfloor and cellular duct, which effectively manage complex datacommunication and power requirements in environments where aesthetics and flexibility are paramount concerns;
• Cable-tray systems, which include ladder, solid bottom, center-spine, and wire mesh trays and which offer a high degree of flexibility; and
• Open-space systems, which serve areas that are not adjacent to partitions or walls.
The market for surface raceway in North America is upward of $200 million. Raceway is used to get wires and cables out of the wall and make them more accessible, according to Don Torrant, manager of communications, training and research at Wiremold Co., West Hartford, Conn. “Perimeter or surface raceway is easy to install and very flexible in terms of moves, adds and changes [MACs],” he observed.
More specifically, according to Randy Woods, product line manager at Panduit Corp., Tinley Park, Ill., surface raceway is used primarily in applications where there is a great deal of retrofit construction in environments of cinderblock and cement walls. “Fishing cable through these types of walls is not an option,” he said. In addition, certain raceway systems allow both power and data cabling to be run side by side, which minimizes the amount of raceway needed and makes the installation more cost-effective and aesthetically pleasing.
There is a bias, however, against raceway systems based on the bulky and unattractive aesthetics of early versions. “Newer designs have eliminated many of those issues,” said Torrant. Surface raceway may also potentially reduce an electrical contractor’s profit margins when performing MAC work. “It takes less time to lay cables through raceway than to fish cables through a behind-the-wall cable management system,” explained Woods.
It is predicted that surface raceway will continue to experience increased customization and more contemporary styling to fit end-users’ specific needs. “Non-metallic raceway could experience growth in outdoor applications, particularly in the residential market because of its non-rusting, durable qualities and its cost effectiveness in long, straight cable runs,” Woods added.
Wire basket and cable tray
The North American market for both wire baskets and cable trays is more that $120 million annually. Cable tray supports all styles of data, communications, telephone, signal, control and power cables, and allows VDV cabling and electrical wiring to be run side by side. Cable tray is considered safe, flexible, versatile, highly resistant to corrosion, easily maintainable and less expensive to install. “Cable tray designs include ladder, trough and channel, and are available in aluminum, pre-galvanized steel, hot-dipped galvanized steel, stainless steel or fiberglass,” said Earl Middelthon, national sales and engineering manager for Chalfant Manufacturing Co., Cleveland, Ohio.
There are, however, some cost considerations when choosing cable tray. “For example,” Middelthon cited, “aluminum systems are more expensive than wire mesh, while ladder systems require factory manufactured fittings, which can increase the costs up to 30 percent.”
Within VDV applications, cable tray is best used in high-volume runs because of its ability to support higher weights, its longer support spans, its open nature and ease of cable pulling and its flexibility for MACs. Recent changes in cable tray have been driven by the continual refinement of codes and standards in VDV applications and Middelthon predicts that trend will continue as codes and standards become increasingly defined.
Wire basket trays, in particular, are relatively lightweight compared to other trays and hold large amounts of communication cabling. Wire baskets also allow installers to react to unforeseen obstacles and turns in the field without having to order special fittings. “Wire basket is also widely stocked through the distribution channel, enabling electrical contractors to get the material quickly and be more flexible in bidding jobs,” said Torrant. They are used widely in schools, government buildings, research rooms, food processing plants, clinics, hotels, petrochemical refineries, financial institutions, airports and so on, and are also becoming increasingly popular in raised-floor applications. Wire baskets are not, however, NEMA-rated for load and bonding jumpers are necessary for them to be used as equipment grounds. “Just like other systems, liners and covers are available if extra security or protection is required,” Torrant added.
Recent improvements to wire baskets relate primarily to labor savings, whether through improved design or the development of new installation tools. “There has also been an increase in the demand for painted wire basket trays for a more aesthetically pleasing appearance,” Torrant observed.
Hooks and bridle rings
The market for hooks and bridle rings continues to grow as they continually increase their percentage of market share. “Depending on the installation, hooks are frequently a more efficient choice and continue to increase their sales over the other types of cable management systems on the market,” stated Kathy Neville, product segment manager for B-Line Systems Inc., Highland, Ill.
Although bridle rings have been used since the advent of the telecommunication industry, the surface that supports the cables is very thin, frequently causing the cables to bend around the metal and create stress points, which reduces performance. Most installers and end-users, therefore, are gravitating toward the use of J hooks because they have a wider surface on which the cables lay flat. “J hooks are easy to install and come in different combinations, including snap-on devices for attaching them to beams, suspended ceilings or other areas,” she stated. And because they do not cause stress points on the cabling, J hooks provide greater reliability.
J hooks are not well suited, however, for longer cable runs, because a hook would be required every four to five feet. “Cable tray, ladder or another type of tray may be more cost-effective than J hooks for that particular type of run,” Neville admitted. On the other hand, J hooks are an excellent choice for installation in congested areas where space is tight or where there is a lot of equipment or ducts to work around. “Both J hooks and bridle rings allow a greater deal of flexibility and versatility in making turns and for making MACs to the cabling system,” she added. Neville also points out that J hooks and bridle rings are not restricted to use in congested areas and that they can be a lower-cost alternative to other methods for straight cable runs.
In the future, J hooks that are bigger and better able to support larger numbers of cables should be developed. “J hooks will continue to see improvements in their manufacture and design and will provide electrical contractors with faster and more cost-effective installation methods. Bridle rings, however, will slowly continue to lose market share to the more advanced hook systems,” Neville predicted.
According to Roger Jette, president of Cable Management Solutions Inc., Bay Shore, N.Y., bendable steel tray accounts for one-quarter to one-third of the VDV cable management system market. Bendable steel tray is easily manipulated, thereby requiring few fittings for turns, and does not require cutting, clipping or modifying. “Because pre-fabrication of the tray is not required in the field, the learning curve for installers is short, and time becomes a constant in terms of preparing project bids,” Jette said. In addition, bendable steel tray is easy to transport because it comes nestled together, taking up less space in the truck and making it easier to carry.
The main disadvantage of bendable steel tray, however, is that it is generally built for discrete, station-to-station cabling runs and not for trunk-type 900-pair cables. “Bendable steel tray is designed more specifically for fiber and Category 5 and Category 6 cables, rather than for large, high pair-count cables,” said Jette. It works well, however, in access control, building management, telephone cabling, coax and video cabling, fiber optics, and Category 5 and Category 6 copper cabling applications.
Next on the horizon for bendable steel tray, according to Jette, is the development of linear bussing systems that run the VDV cables under raised floors. Designed for applications such as computer rooms, these buss systems will eliminate the traditional methods of hard-wiring equipment and will be flexible, convenient, and easy to install.
What contractors are using
When able to specify the cable management system to be used, Ermco of Florida, based in Orlando, tends to choose bridle rings for VDV installations because they offer speed and easy installation. “Bridle rings are less labor intensive and the material less costly to purchase,” explained Scott Maddox, Ermco president. When unable, for whatever reason, to use bridle rings, a lightweight cable tray system is the company’s next choice. “For example, we will choose cable tray when we know that the owner’s system will eventually be expanded,” Maddox said. Generally speaking, the company chooses its cable management system in accordance with local codes and standards and with an eye toward reducing labor and material costs while fulfilling the owner’s requirements for performance.
Over the past year or so, the company has seen more project owners approving the use of cable tray systems as they realize that these new systems will more cost-effectively fulfill their needs. “As the market matures, lighter weight products should continue to be developed, since VDV applications do not generally require the same protection as rugged, corrosive environments,” Maddox observed.
According to Paul Seben, vice president of Advent Systems Inc., Elmhurst, Ill., the use of conduit or enclosed raceway is mandated by code in downtown Chicago. In the suburbs, however, codes demand the use of cable tray or an open support system for voice and bridle rings for CCTV and security systems cabling.
There have been no great advances, technologically speaking, in cable management systems over the past year or so, according to Seben. He observes, however, that J hooks have taken over the lion’s share of the open support market. “Local codes prevalently require the use of J hooks rather than bridle rings,” he concluded. EC
BREMER, a freelance writer based in Solomons, Md., contributes frequently to ELECTRICAL CONTRACTOR. She can be reached at 410.394.6966 or firstname.lastname@example.org.