ECN Forum Forums General Topics of the Trade General Discussion Area "farmers three way" question here

received this in email today.......take it away guys.....this is way over my head.
Thanks.
Tiff

I am looking for information on old wiring called a farmers 3-way.
This is for a school project.
I need to know how to hook up a 3-way switch in a house,a 3-way switch and
a 110 v recepticle in a barn.
The switches will operate a yard light and the recepticle has to be hot all
the time.
There are no ground wires and only 3 wires can be ran from the house to the
barn.

Does this work?

Hot--------\-------------------/-------+
_____3_way__\_(Red)___Light___/_3_Way||Outlet
Neutral----/-------------------\-------+

Pardon my lake of artistic ability.

[This message has been edited by rbiro (edited 10-23-2001).]

The key to this idea is that it is old. I occasionally see this in the main stairwell of early 1900 two story single family dwellings wired with Knob and Tube. The original service was 120 volt only and a lighting circuit went to each floor (or there was only one lighting circuit for both floors). The main stairwell light is not polarized (like I said - OLD . The lamp screwshell is connected to the common of one threeway, and contact tab is connected to the common of the other threeway. The threeway travelers, at the top and bottom of the stairs are connected to the closest available hot and neutral. No concern is shown for cross neutralling (is that a word?) two circuits.

I generally get a call when the home owner has tried to replace a worn switch and gotten the common on the wrong wire. . .always blows the breaker.

Look for California 3-Way Diagrams

[This message has been edited by Joe Tedesco (edited 09-06-2002).]

Look under our Electrical Theory Topics for a topic called "4wire feed for 3 way switching". I think it is the same concept.

i believe this is known as the carter system... atleast thats what ive read in books... it works by switchking both hot and neutral, so you have one less traveller... its rigged, but works

-m

Merrit
Thats the name I have heard it called, also the lazy Neutral.
Also there are more of them out there than you think. K & T were famous for them and even into the late 30's older electricians still used them at that point, in(at that time new construction).
This summer I rewired a house that had 15 of them with 4-ways, except for the switching, Carter system, the minimum size wire was No. 12 old romex, the guy spared no expense, in 1936, but even then that system was against code.

http://www.hometoys.com/htinews/apr98/articles/kingery/kingery8.htm
Here's a link, check fig#7... looks like what's being described ( Bordew, I get these links from the BB's, just obligated to pass them on...)

I would think your best( Nec Legal) option for only a 3 -wire would be automation ( X-10) controls.

Thanks very much for the help.
That was exactly what I was looking for.

Tiff

........?

[This message has been edited by Joe Tedesco (edited 09-08-2002).]