On Tue, 26 Nov 2013 17:40:30 -0500, Nate Nagel
wrote:

On 11/25/2013 04:16 PM, TomR wrote:
Metspitzer wrote:
On Sun, 24 Nov 2013 15:25:16 -0500, "TomR" wrote:

I am trying to solve a 3-way switch circuit issue in an old house.
The
wiring in the house is old, and it is either knob and tube wiring or
whatever came after that and before "Romex" etc. There are no
ground wires
visible anywhere in either circuit, and everything is so dusty and
dirty
that I can't tell what is a white wire and what is a black wire etc.
. . . ,
I found the following link to various 3-way switch wiring options:
http://www.easy-do-it-yourself-home-...g-diagram.html
.

http://imgur.com/mlB47zL
I marked what should be going on. 1 (common) will be hot all the
time. a and b will be the travelers and 2 (common) will go to the
light.
(BTW the color code on the ledger is wrong.) White is a traveler, not
common.

Thanks. You're right. Where it says "White Wire (Common)", it should say
something like "White Wire, coded black (Traveler). And, it looks like they
coded the white wire black where needed to distinguish it from being a
typical neutral wire.



That's correct; electricians don't always do that but any time a white
is used as a non-neutral conductor it should be relabeled with a ring of
colored tape (any color other than white, grey, or green that is.
"normal" colors for residential 120V wiring would be black or red.)
This isn't a suggestion but a code requirement.

I "paint" white wires that are repurposed as hots, with a red Sharpie.
I keep one in my "electrical" toolbox. I don't know if it's kosher but
it works.