Datacom Considerations

From the early days of telegraph and POTS (plain old telephone systems) 
to today's modern IT infrastructures, the transmission of various forms 
of information has increased exponentially.<br><br>Who would have 
guessed that the tap-tap-tapping of early telegraph operators would 
someday be replaced by data whizzing by at the speed of light? IDEAL Industries

Steve Maurer, IME

From the early days of telegraph and POTS (plain old telephone systems) to today's modern IT infrastructures, the transmission of various forms of information has increased exponentially.

Who would have guessed that the tap-tap-tapping of early telegraph operators would someday be replaced by data whizzing by at the speed of light? With these technological advances comes a plethora of products and requirements… with the changes themselves almost reaching light-speed.

The purpose of this article is only to inform you of some of the changes. It is not intended as a guide to installation of datacom systems. I merely want to let you know that today's systems are more than just throwing cable across the floor, ceilings, or through plenums and raceways.

NEC regulations must be followed
Cabling regulations are found in the NEC chapters 700 and 800. The type of installation determines the standards to use in both designing and installing the system, and specifying components.
Requirements are included for abandoned and future-use cabling. Note that the main differences between them are:
  • Abandoned cabling refers to cables from pre-existing installations that are no longer in service. Removal and/or tagging regulations are outlined in the NEC.
  • Future-use cabling are cables pulled in for expansion or future planned usage. They must be marked appropriately as to type and class of cabling and designated use.
Under some conditions, abandoned cabling can be left in place if proper preparation of the exposed ends performed. However, the old cable might not conform to current fire and smoke regulations and should be removed whenever possible. Contractors should examine these situations and consider including cable removal as part of the overall bid price.

Recent changes in the Code also regulate the type of cable and installation requirements for installs in plenums, risers, ceilings and other special locations. Additionally, cable entrances from utility companies are handled differently than in-house infrastructures.

Additional regulation entities
State and local codes may differ from NEC regs. Therefore, always consult these governing entities when designing and installing datacom cabling. Other groups, such as health and educational organizations, may also have certain requirements.

Electrical contractors in today's digital, information-driven world definitely have their work cut out for them. But, staying current on NEC code regulations increases their chance of smooth, problem free installations.


Photo courtesy of IDEAL Industries