€h 05 - Horizontal Distribution System Flashcards
5-1 horizontal pathways
Continuous pathways =
(2)
*Conduit
* containment
5–1 horizontal pathway
Non continuous pathways =
J-hook
5–7
Wet locations =
(3)
* Sand
* gravel
* soil
5–9 considerations for horizontal pathways
Planning purposes =
Hallways
5–9 maximum occupant density
Work area (WA) =
* 100 ft.²
5–9
BAS =
(3)
* Building automation system
* 250ft.2
* pathway capacity - 1 cable each system
5–10 cable diameter
4 pr cable =
.35in
5–10 cable diameter
2-fiber cable =
.18in
5-14 unsuitable conduit
Flexible conduit =
(4)
*Creep
* shift
* sheath damage
*not recommended
5–14 unsuitable conduit
If flexible conduit must be used =
Size increase by one trade size
5-14 acceptable conduit runs
ITS design =
Best direct route
5–14 acceptable conduit runs
Continuous section =
No longer than 100 feet
5–14 acceptable conduit runs
Pull boxes/pull points =
More than 100 feet
5–15 unacceptable conduit runs
Conduit should not be run =
Near heat sources
5-15 unacceptable conduit runs
Aluminum or ENT =
never be placed in concrete floors
5–19 recommended conduit capacity
Cross-section area formula =
.785 x diameter²
5–19 recommended conduit capacity
Q: what is the cross-sectional area if the diameter of the cable is .35? =
.785 x (.35)² = .0962
5–19 been radii for conduits
4 pair cable =
4 times
5–19 bend radii
Multi-pair copper cable=
10 times
5–19 been radii
TBB cable=
8 times
5–20 design with conduit bends
If run requires (2) 90° bends =
Pull point
5–20 designs with conduit bends
Third 90° bend =
Derate the design capacity by 15%
5–20 using three bends in conduit
Third bend may be acceptable =
(3)
* Not longer 33 feet
* conduit size increased
* Bend is 12 inches of cable feed end
5–21 conduit terminations
Protrude through structural floor =
1 inch to 4 inch
5–21 completing conduit installation
Complete conduit install =
(4)
* Clean
* reamed
* capped
* Labeled
5–21 complete conduit install
Equipped with pull cord =
200 lb test rating
5–23 points or pull boxes for conduits
Slip sleeve =
(2)
* Larger than the main conduit
* length 12 times the diameter
5–23 pull points or pull boxes for conduits
Gutter =
sheet metal housing or busduct
5-23
Using slip sleeves and gutters =
except used as splice locations
5-24 pull points and pull boxes
pulling and looping boxes only for cables =
> 2in OD
5–24 choosing pull box size
Q: If (5) 4” conduits are entering in one pull box, what is the required width?
15+8+8+8+8 = 47”
5–26 two general types of access floors
Standard height =
low-profile floors =
* 6 in or higher
* less than 6 in
5–26 access floor components
Access floor consist =
Except longitudinal cross-members (does not belong)
5–26 access floor components
Panel sizes =
18” to 24”
Figure 5.7
* space for tiles
* stringers
* aluminum locking pedestals
* steel footings
5-27 Freestanding and cornerlock systems
restricted installations =
finished heights 12in or less
5–28 design access floor
General office areas finished floor height =
8” or higher
5–28 design access floors
HVAC finished floor height =
12” or higher
5–28 design access floors
Finished floors =
Min 2” of free space
5-29 access floor building structure
Depressed slab =
New construction
5–29 access floor building structure
Normal slab =
Renovated buildings
5–30 floor panel coverings
Computer room =
High-pressure laminate
5–30 floor panel coverings
Office =
Factory laminated
5–31 load bearing capacity
Uniform load capacity =
100 lbf/ft²
5–31 load bearing capacity
Concentrated load capacity =
2000 lbf
5–31 load bearing capacity
General office =
50 lbf/ft²
5–31 load bearing capacity
Dynamic loads =
Falling objects
5-32 - running telecom cables
connecting hardware =
not be placed in access floor with the exception of CP
5-32 Underfloor air distribution on cabling
Access floors maybe used as =
a plenum space for distributing conditioned air
5–33 access floors
Disadvantages =
High initial cost
5–35 ceiling distribution systems
Ceiling zone method =
904 ft.²
5–38 design ceiling system
Min ceiling space =
(2)
* 3” above conduits
* 12” above tray or raceway
5–40 pathway and cable support
Pathways must =
(2)
* Min of. 3” above ceiling tiles
* sufficient space then 6 inch above ceiling tiles
5–40 pathway and cable support
J hooks distance =
100 feet run =
* 5ft apart
* 20 j-hooks
5-41 pathway and cable support
50 or more cables =
cable tray
5–42 cable tray fittings
Used for changing direction =
Except covers (does not belong)
5–43 cable tray types
Ladder =
Two side rails
5–43 cable tray types
Ventilated trough =
Ventilated bottom
5–43 cable tray types
Ventilated channel =
Channel
5–43 cable tray types
Solid bottom =
Solid bottom
5–43 cable tray types
Spine =
Rigid spine
5–43 cable tray types
Basket tray =
Wire mesh
5–45 supporting cable trays
Trays and wire ways =
Supported on 5 feet centers
5–46 ceiling homerun method conduit
One or two boxes =
Inside diameter of 1 inch
5–46 ceiling homerun method conduit
Three boxes =
Inside diameter of 1.25 in
5-46 zone conduit size
250 ft2 - 600 ft2 =
600 ft2 - 904 ft2 =
* 2 trade size conduit
* 2 1/2 trade size conduit
5–50 attaching utility columns
Utility poles =
10ft, 12ft, 15ft
5-52 other horizontal pathways
other types of pathways include =
(5)
* catenary wire (messenger)
*perimeter (surface) raceway
* overfloor ducts
* molding raceways
* poke-thru
5-52 perimeter raceways
perimeter raceways =
(2)
* cubicle furniture
* power run seperate
5–60 horizontal cabling system
Horizontal cabling installed =
(4)
* Star topology
* both ends terminated on same floor
* splices are not permitted, with the exception of fiber pigtails
* bridged taps not allowed
5-60 topology
application specific-devices not used in horizontal cabling =
(3)
* baluns
* splitters
* crossover patch cords
5–61
Centralize optical fiber cabling limited =
984 ft
5–61 centralized optical fiber cabling
Pull through method limitation =
(Desktop)
295 ft
5–61 centralize optical fiber cabling
Q: 1000 ft spool / 295 ft pull-through method =
3 pulls
5-65 multidrop conduit system
Multidrop conduit system recommended =
buildings to preselected locations
5–68 duct floor systems
Junction boxes =
60 ft
5–69 duct system
Distribution ducts =
Distributing cables from the TR to specific floor areas
5–70 duct systems
Feeder ducts =
Connects TR to distribution ducts
5 – 70 duct system
Enclosed feeder j boxes =
5” handhold opening
5–71 feeder duct types
Large lower =
Feeders
5–71 feeder duct types
Standard Upper=
Power
5-71 Feeder duct types
Large upper =
Telecommunications
5–73 design underfloor ducts
Determining duct size =
1 in.² cross-section for each 100 ft.²
5–73 design underfloor duct
Feeder duct size =
8.9 in.² cross-section for each 800 ft.²
5–74 design underground duct
Distribution duct sizes =
(2)
* standard 3.3 in2 - 3.9 in.²
* use larger ducts when area is 60ft - 80ft long
5–75 design underground duct
Slab thickness:
one level =
2 level =
Feeder beam concept =
* 5”
* 7”
* 7”
5–80 terminating ducts
TR duct do not pass =
3 inch to 6 inch
5–80 terminating ducts
TR duct pass =
Elbow
5-93 Cellular Floor System
steel cellular floor =
do not use feeder (conduit to a cell) below deck
5–102 trench duct for under floor
Trench duct cover plates =
4 feet long x up to 38” wide
5–103 removing trench duct cover
Lifting device =
Stored in TR
5–103 removing trench duct cover
Suction cups =
.25” eye bolts
5-103 removing trench duct cover plates
building personnel =
should remove trench duct cover,
but telecom personnel is expecteted remove 1 or 2
5–117 references
TIA-569-B =
Pathways and spaces
