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 MIL-HDBK-1012/3
1.3.2.5
Shielded 150 Ohm Cable. Two pair 150 ohm shielded
cable is not recommended for new construction but may be
encountered in the refurbishing of older buildings. Its presence
may indicate an area of increased EMI and should be approached
accordingly. Shielded cable is prevalent in Europe where
electronic emission standards are more stringent.
1.3.3
Wall-Mounted Outlets and Conduit. Provide flush-
mounted faceplate attached to a 103 cm (4 in.) square by 56 mm
(2-1/8 in.) deep wall box in accordance with EIA/TIA 569. This
requirement is designed to provide sufficient space to allow
coiling of the cables within the box without exceeding the
minimum bend radii. A reducer may be added to allow the
attachment of a single-gang faceplate. The box should be
connected to appropriately sized conduit which is stubbed up into
an accessible ceiling, homerun to the serving telecommunications
closet, or connected to an in-floor distribution system. Conduit
sizes to support wall box configurations are dependent upon the
number and diameter of the distribution cables being run.
Conduit should be sized to accommodate the future installation of
fiber to the desktop. Refer to par. 1.5.1.3.c) of this manual or
EIA/TIA 569, Table 4.4-1, for assistance in sizing conduit. Wall
boxes should be installed at the same height as the electrical
outlets which is normally 42.5 cm (17 in.) above the finished
floor (AFF) measured from the center of the box. Provide wall
mounted outlet in kitchen area within housing units. Outlet
shall be installed 120 cm(48 in.) AFF. Pay telephones are to be
installed 100 to 105 cm (40 to 42 in.) AFF. The Americans With
Disabilities Act requires that the highest operable mechanism on
a pay telephone be within 135 cm (54 in.) side reach and 120 cm
(48 in.) forward reach.
1.4
Horizontal Cable Requirements
1.4.1
Building Usage. The first step in quantifying building
telecommunication cable requirements is the categorizing of the
building by its type of telecommunications usage. Major usage
types, as described below, each have both general and unique
cabling requirements. When uncommon building types are
encountered, the RCDD should consult the major claimant for
specific distribution requirements. Cable distribution density
within a building is dependent upon the buildings projected
functions over a 10-year period. Pathways should be designed for
the life of the building. Premature recabling is time consuming,
expensive, and disruptive to both users and system operations.
To correctly size the cabling infrastructure, the RCDD is
encouraged to select one of the various building usage types
listed below prior to computing the quantity and types of cables
required to support each workstation and the type and size of the
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