Appendix C Industry-Standard Wiring Plans - Cisco 7000 Series Hardware Installation And Maintenance Manual

A P P E N D I X
When you install more than a few terminals, you face the problem of organizing the wiring. AT&T
has devised for the telephone industry a uniform scheme for dealing with large numbers of wires.
The scheme uses two color codes—one for large numbers of wires organized in pairs and the other
for smaller numbers of wires which may also be organized in pairs. We recommend the use of this
wiring scheme whenever possible.
For large numbers of wires, each pair is assigned a two-color code. The colors are selected from two
groups of five, resulting in what is called a binder-group of 25 pairs. The colors used for a group are
white, red, black, yellow, and violet. The colors used for "pair within group" are blue, orange, green,
brown, and slate.
Each pair must have a unique color combination. One wire within each pair has a solid background
of its group color and stripes of the "pair within group" color, and the second wire has the colors
reversed. Table C-1 lists the sequences. Note that red-brown and red-orange wires can be easily
confused.
Table C-1
Pair Number
1
1
2
2
3
3
4
4
5
5
6
6
7
7
8
8
C
Industry-Standard Wiring Plans
Telephone Industry 25-Pair Color Code and Pin Numbers
Wire Number
1
2
1
2
1
2
1
2
1
2
1
2
1
2
1
2
Solid Color Stripe Color
White Blue
Blue White
White Orange
Orange White
White Green
Green White
White Brown
Brown White
White Slate
Slate White
Red Blue
Blue Red
Red Orange
Orange Red
Red Green
Green Red
Pin Number
26
1
27
2
28
3
29
4
30
5
31
6
32
7
33
8
Industry-Standard Wiring Plans C-1