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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 multi-pair 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.