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02-14-04, 02:02 PM

pdesiato

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carter system

Does anyone know where I can find some information on an old wiring system I have always called "The Carter System". It was used some time ago and involved switching neutrals. I am working on an old house where my customer attempted to change his own switches and made a mess of it. I have four
3-gang switch boxes appart as we speak.

Thank You in advance
Pat

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02-14-04, 05:32 PM

John Nelson

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Well, as I assume you know, the Carter System is illegal and unsafe, and has been so for many years. The Carter System is one in which the light is off if either two neutrals or two hots are presented to it, and the light is on when one hot and one neutral are present. It was used when a light was controlled from two locations and was invented to save wire. Unfortunately it sacrificed safety in doing so.

Modern three-way switches always present one neutral and one hot when on, and one neutral and an open circuit when off.

The source of information about the Carter System is the same as the source of any other information: http://www.google.com Type in "Carter System" (including the quotes). Here is the first site Google gave me when I did it.

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