corridors. Except for these, placement of receptacles in
uninterruptible power is required in communications
walls shall be avoided where raised floors are utilized to
rooms, it will be furnished as part of the communications
the maximum extent possible. See Chapter 3: Architectural
system.
and Interior Design, Building Planning, Planning Module,
Main Mechanical and Electrical Rooms. Main
Floor-to-Floor Heights and Vertical Building Zoning, and
mechanical and electrical equipment rooms shall each
Space Planning, Office Space, Utility Placement.
have, at a minimum, one emergency power receptacle
Raised Access Floor. All wiring beneath a raised access
that is identified as Emergency Power at the receptacle.
floor shall be routed in rigid metal or flexible conduit to
Exterior Mechanical Equipment. Provide one receptacle
underfloor distribution boxes. One distribution box per
adjacent to mechanical equipment exterior to the
bay is recommended (see section Placing Electrical Systems
building, including each roof. Receptacles shall be of
in Buildings, Horizontal Distribution of Power and
the weatherproof GFI type. Receptacles must be located
Communications). Flush-mounted access floor service
within 25 ft. (7.62m) of each piece of equipment in
boxes shall be attached to the underfloor distribution
accordance with NEC 210-63.
boxes by means of a modular, prewired system to facilitate
easy relocation.
Toilet Rooms. Each toilet room shall have at least one GFI
receptacle at the vanity or sink. Carefully coordinate the
Conference Rooms. Conference rooms shall be served in
location of the receptacles with all toilet accessories.
the same fashion as general office space, except where
specifically outfitted for audio-visual equipment.
Underfloor Raceway Systems
Maintenance Shops. Maintenance shops require plug-
Underfloor raceways fall into two (2) categories:
mold strips above work benches with duplex outlets 900
A cellular metal deck framing the concrete floor slabs
mm (36 inches) on center. Receptacles shall be wired on
in a steel building, in which the cells are generally fully
alternating circuits. Receptacles or circuit breakers shall
"electrified" by the placement of steel sheets enclosing
be of the GFI type. Provide EPO (Emergency Power Off
the underside of the cells. Access to the individual cells
Stations) and associated contactors for shops containing
is obtained by a series of compartmented header ducts.
freestanding equipment.
The width of the header duct is sized according to the
Electrical and Communications Rooms. Electrical
area served and the depth is 63 mm (2 1/2").
rooms require one emergency power receptacle that
A conventional 3-cell underfloor duct system placed in
is identified as Emergency Power at the receptacle.
a 100 mm (4") concrete fill over the concrete slab in an
The communications room will contain power and
all concrete building. The cells are generally located on
grounding for the passive and active devices used for
1500mm (5') to 1800 (6') centers. Note: This type of
the telecommunications system, including at least two
raceway system is frequently found in existing buildings
dedicated 20A, 120 Volt duplex electrical outlets on
selected for modernization.
emergency power, and additional convenience outlets
The cell assignments in 3-cell systems are generally
at 1800mm (6 foot) intervals around the walls and direct
designated as: (1) power; (2) voice/data; (3) signal.
connection to the main building grounding system. If
198 F A C I L I T I E S S T A N D A R D S
FOR THE
PUBLIC
BUILDINGS
SERVICE
6.10 Branch Wiring Distribution Systems
Revised March 2005 PBS-P100
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