Violet is the standard name in the telecommunications and electronics industry, but it is sometimes referred to as purple. For cables with more than 25 pairs, each 25 pair group is bundled with a colored binder following the same color code, eg: the blue/white binder group is the first, containing cable pairs 1 thru 25. }); White/Blue represents pair 1: eg, White with a Blue band is the tip on pin 26, Blue with a White band is the ring on pin 1. The first group of colors is: white, red, black, yellow, violet. This creates a balanced audio circuit with common-mode rejection, also known as a differential pair. For cables with over 25 pairs, the first 25 pairs, called a binder group, are marked with mylar ribbons using the colors of the color code starting with a white/blue ribbon, the second binder group with a white/orange ribbon, and so on through the 24th binder group, which has a violet/brown ribbon, and forming a “Super binder” of 600 pairs. There are indicators on the mylar ribbons to know where to begin for each layer and a diagram for the different cable sizes should be readily available for reference. History of the 25 Pair AMP connector or RJ21. The names of most of the colors were taken from the conventional colors of the rainbow or optical spectrum, and in the electronic color code, which uses the same ten colors (though in a different order). If looking at the cable’s core and the switch is in that direction, you count the groups counter-clockwise. Back to the list of cabling color codes: 25 pair cable's color code table. The sequence of second group colors can be remembered with the mnemonic: BOGBruSh (Blue, … Optical fiber cables use a twelve-color code, where the first ten are the same as in the 25-pair color code, and the last two are Rose and Aqua. For example, pair 9 is also called the red-brown pair. This supports up to 625 pairs (25 binders x 25 … White/Blue represents pair 1: eg, White with a Blue band is the tip on pin 26, Blue with a White band is the ring on pin 1. Violet/Slate represents pair 25: eg, Violet with a Slate band is the tip on pin 50, Slate with a Violet band is the ring on pin 25. A 25-pair cable is usually terminated with a 50-pin amphenol connector, and it clamps right onto a 66-block. This supports up to 625 pairs (25 binders x 25 pairs per bundle = 625 pairs), though Violet/Slate is not used (therefore, 600 pairs). The color combinations are applied to the insulation that covers each conductor. The RJ21 connector is very similar to the 50-pin Centronics interface, but with screws to anchor it into place instead of bail locks. The major, or primary group of colors consists of the sequence of white, red, black, yellow, and violet. Memorizing the colors Major and minor colors are chosen from two different groups, resulting in 25 color combinations. A 25-pair cable contains 5 groups of 5 pairs each, color coded to show the pair numbers. The minor, or secondary color was chosen from the sequence blue, orange, green, brown, and slate. The binder color sequence is the same as that of the pairs, i.e., the binders for group one are colored White/Blue, for the second group are colored White/Orange, and so on. ... DT-12 Fan-out Color Code (Belden) 2016. With the development of new generations of telecommunication cables with polyethylene-insulated conductors (PIC) by Bell Laboratories for the Bell Systemin the 1950s, new methods were developed to mark each individual conductor in cables. google_ad_client: "ca-pub-3617793371170670", Similarly, slate is a particular shade of gray. Various mnemonics have been used to remember the color coding of the major color groups. Please note that CAT5 cable shown for clarity of the illustrations (tightly twisted conductors). The 25-pair color code, originally known as even-count color code, is a color code used to identify individual conductors in twisted-pair wiring for telecommunications. The minor color was a tracer, consisting of stripes, rings, or dots, applied over the background. The 25-pair color code, originally known as even-count color code, is a color code used to identify individual conductors in twisted-pair wiring for telecommunications. Telephone Wire Color Code (25 Pair) Telephone cables are grouped in fives. Violet/Slate represents pair 25: eg, Violet with a Slate band is the tip on pin 50, Slate with a Violet band is the ring on pin 25. The minor color always matches the major color of its paired conductor. Many PBXs also have this type of connector for their outside connections. 25 Pair / 50 Pin Amphenol Cable with multiple plug type options. If the cable is the “field side”, you count the groups clockwise. It is used to implement a 25-line (or less) telephone connection such as that used in the 1A2 key telephone system. (adsbygoogle = window.adsbygoogle || []).push({}); Each 25 pair group, or unit, as they are also called, is loosely bound with colored binders. This gives 25 color combinations. Starting with the first binder group in the center, the technician counts the cable’s groups in a spiral direction depending on the location of the Central Office or switch. For example, a 900-pair cable will have the first 600 pairs in 24 groups of 25 pairs in a white binder, and the remaining 300 pairs in 12 groups of 25 pairs wrapped in a red binder. Color code & Pin out 25 Pair AMP Connector, RJ21, Amphenol connector. The pattern then starts over with the first 25 pair group as white/blue, and continues indefinitely, in multiples of 600 pairs or parts thereof. The wire pairs are referred to either directly by their color combination, or by the pair number. enable_page_level_ads: true Other color schemes are sometimes used for outdoor cables, particularly outside the U.S., but this color code is common for aerial and underground cables up to several thousand pair in North America.