Telephone Wiring - Pairing and Connector Pin-Outs

Telephone wiring pinout
4 Pair Cat and 2 pair traditional telephone

When discussing telephone wiring, it is common to refer to wires as pairs and not colors. In the image above, you can see the labels T1, R1, T2, and R2. The T and R refer to the terms Tip and Ring. Don't worry about the terms Tip and Ring, other than the white base wire is always Tip and the solid base color is always ring. 

It is more important to remember that Pair 1 is always the Blue pair, pair 2 is always the Orange pair, Pair 3 is always the green pair and brown is always the 4th pair. 

Pair 1 = Blue Pair
Pair 2 = Orange Pair
Pair 3 = Green Pair
Pair 4 = Brown Pair


Telephone Plug Pinout

6C pinout
4 Conductor Modular Plug Pinout​​​​​


Using CAT Wire for Power or Control 

When you need to use a CAT 5/6 wire for power or other control means, it is best to be consistent job to job. Below are a few examples of which colors/pairs to use in various situations.

Using CAT5/6 for Cameras w/ Baluns and power

The Blue pair is used for the balun signal.

. Use the white/blue wire for positive (+) and blue/white for negative (-) on the balun. 

If you need to use the CAT5/6 to power the camera, use the orange pair for positive and the brown pair for ground. Leaving the green pair as a spare.

.  Positive - Use both conductors

. Negative  - Use both conductors


Using CAT5/6 for general power and control

Use the white base wire of a pair for positive and the solid wire as ground.

White / Blue = Positive

Blue / White = Negative

If you need to double up wires, use the following pair matchups

Pair 1    . for Positive
pair 3  . for Negative 

Pair 2   . for Positive
Pair 4   . for Negative


NEVER separate the wire pairs and use mixed white base wires or mixed solids to form a single pathway. Each pair is actually a different physical length due to different twist rates and depending on the usage, you may experience undesirable results. This is extremely important on keypads, card readers or other data transfer uses.

25 Pair

As you move up in pairs, the base color changes. Pairs 6 - 10 use a red base, 11 - 15 use black and so on as seen in the image below. When you reach 50 pair, the color scheme starts over but each 25 pair, known as a binder group,  is wrapped in a mylar color coded ribbon. The first binder group is wrapped in a white/blue ribbon, the second binder group is wrapped in a white/orange ribbon. This process goes out to 600 pair, where it starts all over.  

25 pair color code
25 Pair Color Code