2 Fiber Optics One of the most critical steps before pulling
fiber is to get an accurate measure of the distance of the cable
pull, we usually add approximately 20% to this total for a fudge
factor. Because fiber pulls are typically long runs it would be
disastrous to come up short, if that happens youll end up with a
nickname like shorty and possibly fired. One of the most critical
steps before pulling fiber is to get an accurate measure of the
distance of the cable pull, we usually add approximately 20% to
this total for a fudge factor. Because fiber pulls are typically
long runs it would be disastrous to come up short, if that happens
youll end up with a nickname like shorty and possibly fired.
Slide 3
3 Fiber Optics The goal is to limit the amount of splices
because of the insertion loss and limit the number of bends
especially sharp bends that can cause micro fracturing and
reflection problems. Two factors to consider when installing fiber
are the pulling force and bend radius during the pull. The goal is
to limit the amount of splices because of the insertion loss and
limit the number of bends especially sharp bends that can cause
micro fracturing and reflection problems. Two factors to consider
when installing fiber are the pulling force and bend radius during
the pull.
Slide 4
4 Fiber Optics If the fiber optic cable is going to be
installed in conduit (indoors or outdoors) a mule tape can be
dragged through the conduit and used as a pull rope. Mule tape is
extremely strong (1800-2500lbs) and has footage markings on it that
can be used to gauge the overall footage of the pull. If the fiber
optic cable is going to be installed in conduit (indoors or
outdoors) a mule tape can be dragged through the conduit and used
as a pull rope. Mule tape is extremely strong (1800-2500lbs) and
has footage markings on it that can be used to gauge the overall
footage of the pull.
Slide 5
5 Fiber Optics Once the total distance has been determined the
fiber can be ordered and delivered to the site. What is the first
thing you should do as a technician with the cable reel when it
shows up on site? Once the total distance has been determined the
fiber can be ordered and delivered to the site. What is the first
thing you should do as a technician with the cable reel when it
shows up on site? SHINE LIGHT THROUGH ALL OF THE STRANDS
Slide 6
6 Fiber Optics Once youve determined there are no dark fibers
you can set up for the cable pull. Fiber should always be pulled
directly off the reel not spun over the edge of reel, this will
eliminate cable twists. Indoor rated fiber like distribution or
breakout cable should never be pulled by the jacketing. Once youve
determined there are no dark fibers you can set up for the cable
pull. Fiber should always be pulled directly off the reel not spun
over the edge of reel, this will eliminate cable twists. Indoor
rated fiber like distribution or breakout cable should never be
pulled by the jacketing.
Slide 7
7 Fiber Optics When pulling fiber it should always be pulled by
the aramid yarn, this will require some cable prep. The steps for
prepping a fiber for a pull are as follows; When pulling fiber it
should always be pulled by the aramid yarn, this will require some
cable prep. The steps for prepping a fiber for a pull are as
follows; ARAMID YARN IS TYPICALLY YELLOW AND IS REFERED TO AS THE
STRENGTH MEMBER
Slide 8
8 Fiber Optics 1.Strip back the outer jacketing approximately 2
to 3 feet. 2.Cut away all fiber strands. 3.Cut away the fiberglass
rod(s) and filler strands where applicable. 4.This will leave you
with aramid yarn strength members only. 1.Strip back the outer
jacketing approximately 2 to 3 feet. 2.Cut away all fiber strands.
3.Cut away the fiberglass rod(s) and filler strands where
applicable. 4.This will leave you with aramid yarn strength members
only.
Slide 9
9 Fiber Optics 5.Tie a swivel hook to the aramid yarn. 6.Tape
the aramid yarn and your knot. 7.Then tie your string or rope to
the swivel hook 5.Tie a swivel hook to the aramid yarn. 6.Tape the
aramid yarn and your knot. 7.Then tie your string or rope to the
swivel hook
Slide 10
10 Fiber Optics 5.Do not pull fiber by half hitching to the
outer jacket unless the fiber is specifically designed for that
application. During the cable pull it is important to maintain a 20
times the diameter radius through out the pull. Indoor cable pulled
by the aramid yarn has a pulling force of 300lbs. 5.Do not pull
fiber by half hitching to the outer jacket unless the fiber is
specifically designed for that application. During the cable pull
it is important to maintain a 20 times the diameter radius through
out the pull. Indoor cable pulled by the aramid yarn has a pulling
force of 300lbs.
Slide 11
11 Fiber Optics When the fiber emerges from the conduit a
mandrel should be used to pull the extra length needed in the
closet. By using a mandrel you dont grab the jacketing and exert
pulling force on the strands. A mandrel distributes the force
amongst the whole cable and strength member. When the fiber emerges
from the conduit a mandrel should be used to pull the extra length
needed in the closet. By using a mandrel you dont grab the
jacketing and exert pulling force on the strands. A mandrel
distributes the force amongst the whole cable and strength
member.
Slide 12
12 Fiber Optics
Slide 13
13 Fiber Optics When the fiber is placed such as dressing it
into ladder racks or fiber panels a 10 times the diameter radius
needs to be maintained. If the cable is pulled by the jacket it
will cause stress on the strands and create rippled fiber that will
micro fracture. When the fiber is placed such as dressing it into
ladder racks or fiber panels a 10 times the diameter radius needs
to be maintained. If the cable is pulled by the jacket it will
cause stress on the strands and create rippled fiber that will
micro fracture.
Slide 14
14 Fiber Optics Fiber optic cables rated for outdoor use, such
as direct burial or underground cable will not require the same
prep as indoor cables. A pulling grip with a swivel eye is
typically used when working with cables in an OSP application.
Fiber optic cables rated for outdoor use, such as direct burial or
underground cable will not require the same prep as indoor cables.
A pulling grip with a swivel eye is typically used when working
with cables in an OSP application.
Slide 15
15 Fiber Optics Using a swivel head to pull fiber optic cable
ensures that the fiber strands will not twist up inside the
jacketing and increase the overall attenuation of the fiber.
Outdoor cables are rated to about 600 pounds of pulling force.
Using a swivel head to pull fiber optic cable ensures that the
fiber strands will not twist up inside the jacketing and increase
the overall attenuation of the fiber. Outdoor cables are rated to
about 600 pounds of pulling force.
Slide 16
16 Fiber Optics When pulling long runs of fiber it will become
necessary to pull slack off of the reels, this is done by making a
figure 8.
Slide 17
17 Fiber Optics The figure helps to maintain the concentricity
of the cable and keeps it from getting knotted up and kinked. If
fiber gets kinked it becomes unusable, as you can imagine the glass
would crack within the jacket leaving dark fiber. In some cases you
may have to flip the figure 8 so that the cable feeds off the top.
The figure helps to maintain the concentricity of the cable and
keeps it from getting knotted up and kinked. If fiber gets kinked
it becomes unusable, as you can imagine the glass would crack
within the jacket leaving dark fiber. In some cases you may have to
flip the figure 8 so that the cable feeds off the top.
Slide 18
18 Fiber Optics In some instances innerduct will be installed
before installing the fiber, in OSP applications the conduit in the
manhole is loaded with innerduct.
Slide 19
19 Fiber Optics Innerduct is a plastic conduit used to protect
fiber optic cable and it is common knowledge that if there is
innerduct in the ceiling it is strictly for a fiber optic backbone.
Innerduct comes on 5 to 6 foot rolls preloaded with mule tape or
poly rope. Innerduct is a plastic conduit used to protect fiber
optic cable and it is common knowledge that if there is innerduct
in the ceiling it is strictly for a fiber optic backbone. Innerduct
comes on 5 to 6 foot rolls preloaded with mule tape or poly
rope.
Slide 20
20 Fiber Optics Innerduct being installed through manholes
before the fiber is installed, 3 ducts are installed in one 4
conduit. 6 FOOT REELS, YOU WOULDNT WANT ONE OF THESE REELS TO ROLL
AWAY FROM YOU, THEYRE HARD TO STOP ONCE THEY GAIN MOMENTUM.
Slide 21
21 Fiber Optics When cutting innerduct the technician has to be
careful to not lose the rope in the duct, it is under a lot tension
especially after a pull. Make a circular cut around the innerduct.
When cutting innerduct the technician has to be careful to not lose
the rope in the duct, it is under a lot tension especially after a
pull. Make a circular cut around the innerduct.
Slide 22
22 Fiber Optics Separate the two sections and slit
approximately 18 of innerduct on both sides of your cut. Force the
rope through the slits you made. Separate the two sections and slit
approximately 18 of innerduct on both sides of your cut. Force the
rope through the slits you made.
Slide 23
23 Fiber Optics Cut the rope in the middle fold it back onto
the innerduct and tape it down, the rope will still have a lot of
tension on it so be careful to not let it slip back into the
innerduct.
Slide 24
24 Fiber Optics After the cable is pulled you will need to
install a service loop at each end. The minimum service loop should
be 20 to 25 feet (at both ends). Indoor pathways for fiber are
similar to pathways for copper. After the cable is pulled you will
need to install a service loop at each end. The minimum service
loop should be 20 to 25 feet (at both ends). Indoor pathways for
fiber are similar to pathways for copper.
Slide 25
25 Fiber Optics A separate J hook run should be established for
the fiber backbones. How far apart should J-hooks be spaced? A
separate J hook run should be established for the fiber backbones.
How far apart should J-hooks be spaced? 4 TO 5 FEET APART
Slide 26
26 Fiber Optics Conduit runs must contain no more than 2 90
degree bends per 100 feet. There should be a pull box every hundred
feet. Minimum size for a conduit containing fiber should be 2.
Conduit runs must contain no more than 2 90 degree bends per 100
feet. There should be a pull box every hundred feet. Minimum size
for a conduit containing fiber should be 2.
Slide 27
27 Fiber Optics The maximum distance a multimode fiber can be
pulled is 2000 meters. The maximum distance a single-mode fiber can
be pulled is 3000 meters. If our MM backbone is to exceed 2000
meters than we should install SM fiber to allow up to 3000 meters
for use with led based systems. The maximum distance a multimode
fiber can be pulled is 2000 meters. The maximum distance a
single-mode fiber can be pulled is 3000 meters. If our MM backbone
is to exceed 2000 meters than we should install SM fiber to allow
up to 3000 meters for use with led based systems.
Slide 28
28 Fiber Optics Single-mode fiber used in OSP applications can
be pulled at least 26 kilometers or 15 miles before the signal
needs to be repeated. This is based on a laser transmission system
and distances are dependent on laser output power. Single-mode
fiber used in OSP applications can be pulled at least 26 kilometers
or 15 miles before the signal needs to be repeated. This is based
on a laser transmission system and distances are dependent on laser
output power.