Color Names on Twisted Pair Cable

[Little Bill]

On twisted pair cables such as Cat5, why do some specs call a pairs colors as both being striped?

It's hard to describe what I'm trying to ask so bear with me.
Say they are talking about the blue pair which is a solid blue and a white with blue stripes. Some specs will say use white/blue on one connection and blue/white on another.
Why don't they just say solid blue for one and white/blue for the other?
There is no blue/white and white/blue in the pair.

I was trying to look at a diagram for a phone line hook-up and it would say put the blue/white on the T and the white/blue on the R. Very confusing since you only have 1 solid and 1 striped in a pair.

It's like asking if a zebra is black with white stripes or white with black stripes?:lol:

 

[hbiss]

There is no blue/white and white/blue in the pair.

Well, yes there is depending on the cable manufacturer. Here are four examples of what you will find for pair 1:

white with blue stripe & blue with white stripe
white with blue stripe & solid blue
solid white & blue with white stripe
solid white & solid blue

You have to look carefully sometimes to discern the body color from the stripe. These all mean the same thing if you know your color code. The white is always T and the color is always R.

-Hal

 

[iwire]

Just like Hal I see pairs that are both striped

 

[Little Bill]

Well, yes there is depending on the cable manufacturer. Here are four examples of what you will find for pair 1:

white with blue stripe & blue with white stripe
white with blue stripe & solid blue
solid white & blue with white stripe
solid white & solid blue

You have to look carefully sometimes to discern the body color from the stripe. These all mean the same thing if you know your color code. The white is always T and the color is always R.

-Hal

Just like Hal I see pairs that are both striped

Pictures Please! All the Cat5E cable I have is 1 solid and 1 white w/stripe in a pair.
Also, all the diagrams for the jacks and plugs show 1 solid and 1 white w/stripe.

Is it the fact that the designated color is listed first?
Such as orange/white would be the solid and white/orange would be the stripe?

 

[Smart $]

....

Is it the fact that the designated color is listed first?
Such as orange/white would be the solid and white/orange would be the stripe?

With single-stripe wire, the base color is listed first, the trace color second.

 

[Dennis Alwon]

I think what Bill and I see is this. I have no doubt there are many other forms of this

 

[hillbilly1]

Generally, it's on cables with more than four pairs, a different color of stripe indicates a different set of pairs.

 

[zbang]

In more depth-
the major colors are White, Red, BlacK, Yellow, Violet (not 'purple') W/R/Bk/Y/V
the minor colors are BLue, Orange, Green, BRown, Slate (not 'gray') Bl/O/G/Br/S

This gives 25 pairs of colors. Note that there are three names starting with B, so they use two characters (Bl, Bk, Br), the rest use one.

So, the first pair is W/Bl (white/blue), and the last is V/S (violet/slate), but there are also 24 and 20 pair cables or bundles. Doesn't matter whether the individual wires are marked or what, just as long as you can tell it's the W/BL pair and which is which. I've seen solid colors, stripes along the length of the wire, and the old classic color bands around the wire. When you have more than 25-pairs in the cable, groups of 20 or 25 pairs are individually bundled with colored plastic tape (or threads in the Old Days), and usually following the same color scheme. So, you might have White, Red, and Black bundles in a 75 pair cable. (The 1A2 key system, the most common setup, designated the last five pairs for a speakerphone connection, so Ma Bell often used a 20-pair cable instead of 25.)

In any pair, the major color comes first, and is attached to the 'tip' lead of a POTS line, which is where it all started. Also, do not confuse pair order with the lead placement on a 25-pair Amphenol connector; those pins are numbered 1-25 down one side and 26-50 on the other, so the first pair uses pins 1 & 26.

Probably more than you wanted to know on a Sunday morning . Discussion of tip & ring, and why twisted pair Ethernet does not use an RJ-45 connector, is left to another day.

 

[Dennis Alwon]

Generally, it's on cables with more than four pairs, a different color of stripe indicates a different set of pairs.

I wondered about that since all the images I could find had only 4 pair and the setup as shown.

 

[Little Bill]

In any pair, the major color comes first, and is attached to the 'tip' lead of a POTS line, which is where it all started. Also, do not confuse pair order with the lead placement on a 25-pair Amphenol connector; those pins are numbered 1-25 down one side and 26-50 on the other, so the first pair uses pins 1 & 26.

Probably more than you wanted to know on a Sunday morning . Discussion of tip & ring, and why twisted pair Ethernet does not use an RJ-45 connector, is left to another day.

Thanks Zbang! Maybe a little more than I wanted to know!

I do know about it not being an RJ-45 connector, it is an 8P8C connector!:thumbsup:

 

[GoldDigger]

In more depth-
the major colors are White, Red, BlacK, Yellow, Violet (not 'purple') W/R/Bk/Y/V
the minor colors are BLue, Orange, Green, BRown, Slate (not 'gray') Bl/O/G/Br/S

This gives 25 pairs of colors.

And as long as you can clearly identify the two wires which form each twisted pair there is no need to use stripes or bands of the minor color on the major wire, or vice versa. A CAT-5 cable has a very pronounced twist and a small enough number of pairs that it is hard to mix up the four white wires.
But for a cable with a shallower twist and a larger number of pairs, the ring or stripe method makes it much easier on the person working to terminate it. (Or even worse, to splice it.)

 

[hbiss]

http://www.fiberoptics4sale.com/wordpress/wp-content/uploads/2011/01/13-23_multi-pair_cable.gif

and there is this:

http://www.nailbat.com/gallery/d/3910-2/25pairdetailed.jpg


-Hal

 

[erickench]

I know that in twisted pair cable there are bundle designations that are also color coded. A bundle contains many pairs that are color coded.

 

[hbiss]

I know that in twisted pair cable there are bundle designations that are also color coded. A bundle contains many pairs that are color coded.

Not bundle but binder. No matter how may pair count a cable is it is always made up of multiples of the 25 pair I gave you above.

-Hal

 

[Speedskater]

I was looking through my very old Belden Wire and Alpha Wire catalog's for something else. I noticed that the Belden catalog had 5 wire color codes and the Alpha had 11 codes.

 

[zbang]

Not bundle but binder.

Yes :slaphead: binder group. Been a while since I thought about them.

 

[DaveTap]

OK here's cat5e cable (25 pairs)
Now do you see why they have blue w/wht stripe and white w/blue stripe etc?
Phone cables can have 1000's of pairs.
Interesting info: http://en.wikipedia.org/wiki/25-pair_color_code

 

[hbiss]

I was looking through my very old Belden Wire and Alpha Wire catalog's for something else. I noticed that the Belden catalog had 5 wire color codes and the Alpha had 11 codes.

Not all of them were for telecom twisted pair cable. Both manufacturers make many kinds of low voltage and communications cables. You were probably looking in the catalog section that gives the colors for all their cables.

-Hal