Published last year, new terms now exist for telecommunications pathways and spaces.
March 1, 2013
he ANSI/TIA-569-C standard, published in May 2012, replaces the TIA-569-B standard including Addendum 1 and has been substantially reorganized and revised to provide “generic” requirements for telecommunications pathways and spaces for all types of customer premises. Additional requirements and exceptions that are specific to the type of premises have now been moved to the specific premise document, e.g. the commercial premises information is an addendum to 568C-1.
In order to make this standard generic it was necessary to define new terms for telecommunications spaces.
The term “distributor room” is used to denote a telecommunications room or an equipment room. The term “distributor enclosure” is used to denote a telecommunications enclosure. The term “common distributor room” is used to denote a common telecommunications room or a common equipment room. The term “equipment outlet space” is used to denote a telecommunications outlet space.
The size requirements for distributor rooms in ANSI/TIA-569-C are specified relative to the number of equipment outlets served.
This is different than the TIA-569-B standard where the size requirements for telecommunications rooms were specified by floor area served. These requirements for commercial buildings are now contained in ANSI/TIA-568-C.1.
Also, spaces specific to commercial buildings such as multi-user telecommunications outlet assembly (MUTOA) space and consolidation point space can be found in ANSI/TIA-568-C.1-1.
Other major changes for telecommunications spaces include class names for temperature and humidity that align with the new ASHRAE classes and also requirements for lighting that are now specified in the vertical and the horizontal plane. Requirements were also added for cabling in open ceilings and on structural columns.
One noticeable change is that conduit fill requirements and calculations were removed in the new edition of the ANSI/TIA-569-C standard.
The reason for this is that the maximum number of cables that can be installed in a given size conduit is not only related to the space available, but also depends on the maximum pull tension limit.
Among other factors, the pull tension limit is based on the geometry of the conduit system, the position of the bends, the length of the conduit system, the tensile strength of the cable and whether a lubricant is used.
It is up to the designer of the cabling system and installation contractor to ensure that pulling tension limits are not exceeded for the conduit system and the type of cable being installed.
The ANSI/TIA-569-C Standard provides specific guidance on conduit installations as follows:
• No section of conduit shall be longer than 30 m (100 ft) between pull points.
• No section of conduit shall contain more than two 90 degree bends, or equivalent, between pull points (e.g., outlet boxes, pull boxes, distributor rooms).
• Care should be practiced in lubricant selection, taking into consideration compatibility with cable jacket composition, safety, lubricity, adherence, stability and drying speed
(Note: For more information on conduit fill, the reader should also consult the 2011 National Electrical code, Chapter 9 Table 1 and Table 4.)
An important addition to the ANSI/TIA-569-C standard is the recommended separation between telecommunications and power cables for different electrical noise environments.
This is a topic that I get frequently asked questions from cabling designers. I have summarized some of the requirements in the chart on the left, which is a graphical representation of the minimum separation distance depending on the type, amperage and the number of power circuits for an E1 (commercial) environment. This is provided as an example. Please consult the standard for more information on how to apply these guidelines.
In summary, the new edition of the ANSI/TIA-569-C Standard has been expanded to include generic requirements for all types of customer premises. It is an important piece in the new series of telecommunications cabling “common” standards. CNS
Paul Kish is Director, Systems and Standards at Belden. The information presented is the author’s view and
is not official TIA correspondence.