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Telecom Cabling
25 pair color code and high count cables
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Telecom Cabling
The 25 pair color code expands on the 4 pair color code
that you’re already familiar with.
We will look at the 25 pair color code and then apply it
to higher count cables like: 100 pr., 200 pr., etc.
The 25 pair color code can be found in your Data,
Voice and Video Cabling book 3rd edition page 69.
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Telecom Cabling
25 pair color code.
Tip colors are; white, red
black, yellow & violet.
Ring colors are: blue, orange
green, brown & slate
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Telecom Cabling
We always refer to the 1st pair as the white/blue pair,
however because it is a “pair” it is technically the
white/blue blue/white pair.
This applies to all the pairs, for instance pair 6 is the
red/blue blue/red pair.
Each pair has a tip and a ring conductor, tip is positive
and ring is negative.
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Telecom Cabling
The 25 pair color code is applied to high count cables in the
same manner as regular pairs.
For instance in a 100 pair cable there are 4, 25 pair cables, in a
200 pair cable there are 8, 25 pair cables.
A 100 PR. CABLE WITH
4 BINDERS
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Telecom Cabling
Each 25 pair cable is like a single pair in the color code
and is called a binder.
OUTSIDE PLANT CABLE
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Telecom Cabling
Therefore each binder can have a color assigned to it all
the way up to 625, (25 X 25= 625) pair.
The last or 25th (violet/slate) binder is not used.
After the 600 pair count we then go into “super
binders” and apply the color code again.
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Telecom Cabling
The binder color code.
Note that it is the same 25
pair color code except that
binders are identified as the
ring conductor colors, i.e.
the first 25 pair is the
blue/white binder.
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Telecom Cabling
When you open a 100 pair cable you will see the first
25 pair wrapped in a blue or blue/white nylon tape.
The second 25 pair is wrapped in an orange or
orange/white tape and so on…..
BLUE/WHITE TAPE
IDENTIFING THE FIRST
25 PAIR.
THE ORANGE AND
GREEN BINDERS CAN BE
SEEN IN THIS CABLE
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Telecom Cabling
Here is a 1200 pair splice in a manhole, this is where
the super binders are used.
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Telecom Cabling
Super binders are identified with the same color code
however a super binder contains 600 pair.
So a 1200 pair cable has 2 super binders.
Can you guess the colors of the two super binders?
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Telecom Cabling
The first 600 pair is wrapped in a white nylon tape and
the second 600 pair is wrapped in a red nylon tape.
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Telecom Cabling
binders in multi-pair cables start in the middle of the
cable and binders are found counter clockwise
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Telecom Cabling
Multi-pair cables are CAT 3 rated so the twist rate is
very slight as opposed to CAT 5e/6.
CAT 5e multi-pair cable is available up to 100 pair,
however 25 pair CAT 5e is the most common and
normally used in IT rooms or data centers.
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Telecom Cabling
Multi-pair cables are typically riser rated (CMR) and
are designed for indoor or outdoor use, indoor multipair cable can not be used outdoors.
Outside plant cable is black and has a corrugated
armored sheath.
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Telecom Cabling
The armor is for protection from rodents, i.e. rats,
gophers, prairie dogs etc.
For long spans in a riser system armored cable should
be used for added strength in supporting the cable.
In a riser system the cable is to be supported in two
places on each floor.
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Telecom Cabling
Unistrut is used as a base and then unistrut clamps or
split kelem grips are used to secure the cable.
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Telecom Cabling
The cables used outdoors are typically plastic insulated
conductors (PIC) and the pairs do not have tracer
colors.
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Telecom Cabling
If these cables are not handled properly the pairs will
untwist and you won’t know which white tip conductor
goes to which ring conductor.
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Telecom Cabling
OSP cable is gel filled and has a sticky glue like
substance in it called “icky pic”.
A citrus based cleaner is needed to wipe the icky pic
and gel off the cable.
A chemical called hydrasol is used for cleaning and
prepping the cable, it is non toxic and is citrus based.
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Telecom Cabling
These OSP type cables are found in the main
distribution frame (MDF) or entrance facility (EF) of a
building which is usually in the basement of all
commercial buildings.
These cables are typically terminated by the
telecommunications utility i.e. (AT&T) but they are
sometimes used in riser systems too.
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Telecom Cabling
Terminating 300 pair onto 66 blocks; counts start at the top
left and work down then start back up at the top right of the
block.
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Telecom Cabling
Terminating 110 blocks is a little easier because 300
pair 110 termination blocks are available.
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Telecom Cabling
To help speed up the process of terminating high count
cables there is a 5 pair punch too.
This tool works real well for punching on C4s and C5s.
The head can be pulled off to turn
the cutting blades in just like you
regular punch tool
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Telecom Cabling
One word of caution, it is easy to accidently swap
binders when forming them into termination blocks
which is why you should always have retrievable slack
that you can use to fix any mistakes.
We usually form small binder loops in the back of the
blocks for this purpose…..
Prepare for the worst and hope for the best.