DESIGN!!GUIDELINES!!!!!
CONDUITS AND BACKBOXES
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Pathways for Communications Systems
1. Interior Communications Pathways shall provide for the placement of cables between
building levels and/or between TER and TCs within a building, or the placement of
horizontal cables and outlets, and consist of cable tray, caddy supports, conduit,
sleeves, surface mounted raceway, etc. The pathways shall comply with TIA/EIA-569-A
standards.
2. Inaccessible ceiling areas, such as lock-in ceiling tiles, drywall or plaster, will not be
used as distribution pathways. Should the contractor find inaccessible ceiling areas as
the only available pathway, the contractor will notify the Owner immediately for
direction prior to proceeding with the cable installation.
3. Size and Count
3.1. The count and size of interior pathways are dependent on the number of services
being installed and the number and type of cables the pathways support. Pathways
will not be shared with any other service (e.g. electrical).
3.2. The minimum conduit size for communication pathways is 1.25”.
4. Cable Tray
4.1. Cable tray will have minimum dimensions of 12" wide x 4" deep. Above ceiling cable
tray can be solid or wire basket. Under ceiling cable tray must be solid. Cable tray
must maintain a 40% or less fill capacity at installation. Cable tray shall be installed
above the corridor ceiling grids at nominal height of 1’ above the ceiling grid. The
cable tray will not interfere with, or be placed within 12” of lighting fixture ballasts
or duct work. Conduits pipes or sprinkler heads are not to go through the cable tray.
Cable tray mounting methods will include wall brackets for tray adjacent to a wall
and trapeze for tray not adjacent to a wall. All mounting methods must meet
manufacturer’s recommendations and be sized and spaced according to load. Cable
tray will NOT penetrate walls.
5. Conduit
5.1. Conduit pathways shall be installed according to the following:
5.1.1. Minimum conduit size for communication pathways is 1.25”.
5.1.2. Conduits shall maintain a 40% or less fill capacity
5.1.3. Conduits shall have no more than two 90 degree bends (radius a minimum of
40”) before a pull box is installed
5.1.4. Conduits shall run no more than 300’ before a pull box is installed
5.1.5. Conduits shall be parallel with or at right angles to walls or ceilings
5.1.6. Conduit ends shall be bushed, reamed and grommeted
5.1.7. Conduits shall have a gentle sweep into the cable tray in the direction of
cable route so as to avoid sharp cable bends
5.1.8. Conduits stubbed above the ceiling shall be turned in toward the room
5.1.9. Conduits and all inner-ducts, shall have a pull string installed
5.1.10.
Conduits shall not be shared with other services, i.e., CATV, public
utilities, etc.
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Issued:
06.01.09
Revised:
Contact Person: Manager Standards and Design
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DESIGN!!GUIDELINES!!!!!
CONDUITS AND BACKBOXES
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6. Surface Mounted Raceway
6.1. Fully enclosed non-metallic surface mounted raceway with side access shall be used
to facilitate the placement of cabling in situations where access above the ceiling is
not provided. The most common situation will be areas where hard ceilings exist.
6.2. Panduit T70 or TG70 non-metallic raceway series will be the raceway installed. The
model number will be dependent upon the application and the number of cables to
be routed. Fill capacities must be maintained at 40% or less.
6.3. Placement will typically be against the wall and below the ceiling, but final
determination will be an implementation task order.
7. Non-Firewall Penetrations
7.1. Penetrations through non fire-rated walls will use 4” bushed, reamed and
grommeted sleeves as the transition through walls and cable tray runs. The number
of sleeves will be dependent upon the quantity of cables to be supported while
maintaining 40% or less fill capacity.
8. Firewall Penetrations
8.1. Firewall penetrations shall be made utilizing a fire-rated cable pathway. The number
of penetrations will be dependent upon the quantity of cables to be supported while
maintaining a 40% or less fill capacity.
9. Flush Mounted Outlets
9.1. Flush mounted outlets (except AVM outlet) will consist of a 4" x 4" x 2.75” outlet
box with a single gang plaster ring. A 1.25” metallic conduit, bushed, reamed and
grommeted, will be stubbed from outlet box into the ceiling space.
9.2. All boxes and related wiring shall be held firmly in place and the mounting shall be
plumb and square. All boxes shall be rigidly and securely mounted to building
structure. All boxes shall be installed so that wiring contained in them is accessible.
Install blanking devices or threaded plugs in all unused holes.
10. AVM (Audio/Visual Main) Outlets
10.1. AVM outlets will consist of five 1.25” conduits stubbed in ceiling space and ending
in AV cabinet
11. Lab Surface Mounted Raceway
11.1. Raceway in the computer lab will be mounted on three walls around the perimeter
of the room. Non-metallic Panduit Twin-70 will be used. All raceway and
faceplates will be International White. AC power can be run in the power channel
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Issued:
06.01.09
Revised:
Contact Person: Manager Standards and Design
Page 2 of 3!
DESIGN!!GUIDELINES!!!!!
CONDUITS AND BACKBOXES
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provided. All electrical outlets in the raceway will be divided among eight dedicated 120
volt 20 amp circuits. All outlets shall be isolated ground.
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PRODUCTS
1. Firewall Penetrations
1.1. Fire-rated device containing an intumescent insert material that adjusts
automatically to cable additions or subtractions.
1.2. Complies with requirements of applicable local codes, NEC, and UL.
1.3. Shall include both internal and external firestopping.
1.4. Capable of providing an F rating equal to the rating of the barrier in which the
device is installed.
1.5. Tested for smoke leakage (L rating) and shall not require the se of any optional
sealing materials to achieve the published rating.
1.6. Shall utilize a fire and smoke sealing system that automatically adjusts to the
addition or removal of cables.
1.7. Shall be capable of allowing a 0 to 100-percen visual fill of cables.
1.8. Shall require no maintenance and shall accommodate future cable changes without
mechanical adjustment and/or removal or replacement of protective materials.
1.9. Shall be modular and shall provide mechanical installation options for common wall
and floor constructions as well as common construction conditions including oversized or damaged openings or existing sleeves.
1.10.
Specified Technologies EZ-PATH or approved equal.
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END OF SECTION 27 05 28
2. Non-firewall Penetrations
2.1. 4” bushed, reamed and grommeted sleeves.
INSTALLATION
1. Firewall Penetrations
1.1.1. Firewall penetrations shall be made utilizing a fire-rated cable pathway. The
number of penetrations will be dependent upon the quantity of cables to be
supported while maintaining a 40% or less fill capacity.
2. Non-firewall Penetrations
2.1. The number of sleeves will be dependent upon the quantity of cables to be
supported while maintaining 40% or less fill capacity.
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Issued:
06.01.09
Revised:
Contact Person: Manager Standards and Design
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