How To Remember The 25 Pair Color Code Used In The Cat 5 Cable
As in many other places in electronics, even cables use color coding so that
they can be easily identified. The Cat 5 cables use a color code made of 25
pairs, so that they can be recognized easily when making the connections. These
are the colors of the pairs that are twisted upon each other. Since Cat 5 cables
are unshielded twisted pair cables, the color coding method becomes quite easy
to remember which wire goes where. This is useful knowledge to have when attaching
the RJ45 plug.
This is the way the 25 colored pairs are made: Wires within the Cat 5 cable
are always twisted in pairs. These are called - only for convenience and for
no other reason - as wire 1 and wire 2. Now, wire 1 can come in five different
colors and wire 2 can come in five different colors. Therefore, the total number
of pairs that can be made are 5x5 = 25.
The colors used for the first wire in order are white, red, black, yellow, violet.
For the other wire, the colors are blue, orange, green, brown and slate. Most
amateurs find it tough to remember these combinations, but here are two simple
mnemonics that can help you remember.
- For the first wire combination, remember 'Why Run Backwards, You'll Vomit'.
The first letter of each word represents the colors, and in the same order
- White, Red, Black, Yellow, Violet.
- For the second wire combination, remember 'Body Odor Gives Bad Smell'. Again,
the first letter of each word represents the colors in the same order - Blue,
Orange, Green, Brown, Slate.
Once you remember the order of the colors, it is easy to remember all the colors
that make up the 25 pair Cat 5 cable. You can construct a table as follows:-
| |
|
Color of Wire 2
|
|
|
|
Blue
|
Orange
|
Green
|
Brown
|
Slate
|
|
Color of Wire 1
|
White
|
Blue - White
|
White - Orange
|
White - Green
|
White - Brown
|
White - Slate
|
|
Red
|
Red - Blue
|
Red - Orange
|
Red - Green
|
Red - Brown
|
Red - Slate
|
|
Black
|
Black - Blue
|
Black - Orange
|
Black - Green
|
Black - Brown
|
Black - Slate
|
|
Yellow
|
Yellow - Blue
|
Yellow - Orange
|
Yellow - Green
|
Yellow - Brown
|
Yellow - Slate
|
|
Violet
|
Violet - Blue
|
Violet - Orange
|
Violet - Green
|
Violet - Brown
|
Violet - Slate
|
Thus, all the 25 colors of the code can be memorized quite easily with the
help of simple memory aids. It must be remembered though that these 25 pair
Cat 5 color codes are basically American, and other countries may be using different
codes for their cables.
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