Daily Facts
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U.S. Residential Phone Wiring

November 9th Fact-of-the-Day

Some telephones, answering machines, modems, and other equipment will not function correctly if the telephone line polarity is not correct. The polarity of the wiring to many phone outlets in U.S. homes is wrong, because of confusion resulting from a change in residential telephone line colors years ago or because home-owners installing their own lines haven't realized that importance of polarity. The two wires that comprise a phone-line pair are named 'tip' and 'ring,' because they connected to the tip and ring of a patch cord plug used by telephone operators long ago. Residential lines used to have green tip wires and red ring wires. Now green is a ring color and red is a tip color in multi-line installations. Someone extending an old line with newly purchased wire and color-marked connectors is very apt to cross the polarity. ©2004 Martek International All rights reserved.


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