Copper Pair Color Coding

by Catatonic Dismay

When you're in a phone cable that houses 25-pairs of wire or more (sometimes 250 pairs), how do you figure out which wire belongs to the other and which is ring and tip?  And why would you want to know this?

Well, if you wanted to set up your own junction box in your back yard (for whatever purpose that may serve, and it is not my fault if what you do isn't legal), or if you wanted to tap a line or mingle with the telco staff or pass as one of them, it might be worthwhile to learn a little of this.

Now as for the first question, it is quite easy if you commit two sets of five colors to memory.  The wires have a main (or a base) color and a stripe (or a secondary).

When the main color on the wire is in Column 1, it is Ring.

When the main color on the wire is in Column 2, that wire is Tip.

Figure 1

Column 1
Column 2




Blue
White



Orange
Red



Green
Black



Brown
Yellow



Slate
Violet

"This is all great, but how do I find a pair of wire amongst 100 others in the first place?"

Well, if you have a wire where the main color is orange and the stripe is black, you would find the wire that has the main color black and the stripe color orange.  You now have your Ring and Tip, respectively.

With this system you could have 25 pairs.  Now what happens if you get into a cable that has 200 wires making 100 pairs?

If you cut off about a foot of the outer covering you would see that a type of lacing or colored twine separates the pairs of wire into four section of 25-pairs of wire (when dealing with phone lines of 100 pairs of course).

The cord, or twine, commonly called a "binder," is wound spirally around each section of 25-pairs of wire.  In each of the binders you will undoubtedly find one of the wires in Figure 2.  In this table notice each pair is given a number.

Figure 2

Pair Main-Stripe Tip 1 White-Blue Ring 1 Blue-White Tip 2 White-Orange Ring 2 Orange-White Tip 3 White-Green Ring 3 Green-White Tip 4 White-Brown Ring 4 Brown-White Tip 5 White-Slate Ring 5 Slate-White Tip 6 Red-Blue Ring 6 Blue-Red Tip 7 Red-Orange Ring 7 Orange-Red Tip 8 Red-Green Ring 8 Green-Red Tip 9 Red-Brown Ring 9 Brown-Red Tip 10 Red-Slate Ring 10 Slate-Red Tip 11 Black-Blue Ring 11 Blue-Black Tip 12 Black-Orange Ring 12 Orange-Black Tip 13 Black-Green Ring 13 Green-Black Tip 14 Black-Brown Ring 14 Brown-Black Tip 15 Black-Slate Ring 15 Slate-Black Tip 16 Yellow-White Ring 16 White-Yellow Tip 17 Yellow-Orange Ring 17 Orange-Yellow Tip 18 Yellow-Green Ring 18 Green-Yellow Tip 19 Yellow-Brown Ring 19 Brown-Yellow Tip 20 Yellow-Slate Ring 20 Slate-Yellow Tip 21 Violet-White Ring 22 White-Violet Tip 22 Violet-Orange Ring 22 Orange-Violet Tip 23 Violet-Green Ring 23 Green-Violet Tip 24 Violet-Brown Ring 24 Brown-Violet Tip 25 Violet-Slate Ring 25 Slate-Violet

Experienced linemen know this table by heart (well... some of them).

When they talk about "pair 22," they're talking about wires orange and violet.  If you want to know a lot more than you really need to know (or you want to mingle with the linemen and/or pose as one) than read on.

Pairs of wire are identified sometimes by a number as you have seen earlier.  Pair 20 would be yellow and slate.  But how do you identify wires by number when there are over 25 in the cable?  Remember binders that wrapped around 25 pairs of wire?

They are colored to distinguish between them as well.  The first binder is blue, the second is orange, the third is green, etc.  Sometimes the binders have two colors.  The colors follow in the same order as they do in Figure 2.

The first binder would be orange and blue, the second would be orange and white, the third would be orange and green, etc.

If there are 100-pairs of wire in a cable and four binders separating them into sections of 25, what would pair 78 be?  It would be the third in the fourth binder - or the green and white wires in the brown and white binder.

Yes, this is a lot to soak up in one reading and only someone dedicated to telephony would know this.  I don't know what pair 102 would be without a reference.  I personally don't really need to know that.  If I wanted to pass off as a linemen, I would go through it.

Hacking open a cable (please know what you are doing and don't cut into power lines), to tap or whatever it is you're going to do, and finding a ring and pair isn't all too hard with this information.