CECAD 25 PAIR

Industry Standard Wiring Plans

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. Cisco Systems recommends that you use 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 a "pair within group" are blue, orange, green, brown, and slate.

 

Table B-1 Telephone Industry 25-Pair Color Code and Pin Numbers

    Punch Block                Wire Color              Connector       

Pair

Number

Wire

Number

Solid

Color

Stripe

Color

Pin

Number

1

1

White

Blue

26

1

2

Blue

White

1

2

1

White

Orange

27

2

2

Orange

White

2

3

1

White

Green

28

3

2

Green

White

3

4

1

White

Brown

29

4

2

Brown

White

4

5

1

White

Slate

30

5

2

Slate

White

5

6

1

Red

Blue

31

6

2

Blue

Red

6

7

1

Red

Orange

32

7

2

Orange

Red

7

8

1

Red

Green

33

8

2

Green

Red

8

9

1

Red

Brown

34

9

2

Brown

Red

9

10

1

Red

Slate

35

10

2

Slate

Red

10

11

1

Black

Blue

36

11

2

Blue

Black

11

12

1

Black

Orange

37

12

2

Orange

Black

12

13

1

Black

Green

38

13

2

Green

Black

13

14

1

Black

Brown

39

14

2

Brown

Black

14

15

1

Black

Slate

40

15

2

Slate

Black

15

16

1

Yellow

Blue

41

16

2

Blue

Yellow

16

17

1

Yellow

Orange

42

17

2

Orange

Yellow

17

18

1

Yellow

Green

43

18

2

Green

Yellow

18

19

1

Yellow

Brown

44

19

2

Brown

Yellow

19

20

1

Yellow

Slate

45

20

2

Slate

Yellow

20

21

1

Violet

Blue

46

21

2

Blue

Violet

21

22

1

Violet

Orange

47

22

2

Orange

Violet

22

23

1

Violet

Green

48

23

2

Green

Violet

23

24

1

Violet

Brown

49

24

2

Brown

Violet

24

25

1

Violet

Slate

50

25

2

Slate

Violet

25

Cables with more than 25 pairs of wires are constructed from 25 pair groups. Very large cables have other variations generally not encountered inside terminal wire plants.

For smaller numbers of wires, such as wires for an individual telephone station or terminal, you can use a second color code scheme. Table B-2 shows this color code and the usual correspondence with the paired-wire color code. The alternate color code is included because sometimes the station wire uses the first three pairs of the standard color code (white-blue, blue-white, and so on), while other times it uses the six alternate colored wires.

Table B-2 Second Color Code Scheme for Smaller Numbers of Wires

Pair

Number

Wire

Number

Solid

Color

Stripe

Color

Alternate

Color

Pin

Number

1

1

White

Blue

Green

4

1

2

Blue

White

Red

3

2

1

White

Orange

Black

2

2

2

Orange

White

Yellow

5

3

1

White

Green

White

1

3

2

Green

White

Blue

6

   

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