On 2010-10-28, Karl Townsend wrote:
About the time my old 'puter crashed and burned, I asked about tracing
wire from an operator panel to find each wire's function. I lost the
replies to this post, sorry. The job has changed slightly as we're
trashing the old panel and building a new one.

Anyway, I now have a comparitively easy job of wringing out two fifty
conductor cables. I could just pull in multi color cable and be done
with it, but I'm a cheap a$$.

Anyway, I remember somebody had a quick and nifty way to wring out
wires when you have both ends of a cable without markings. How, again?

Do you mean "ring" out? (The old way, before voltage sensitive
semiconductor devices, involved a battery, a long wire, and an electric
doorbell or buzzer -- thus the "ring". "Wring out" sounds like you
are trying to get rid of water from it.

You could use a phone technician's "fox and hound" (one puts an
electrical noise on the wire, and the other listens for it -- usually
just by putting the probe near the wires outside the insulation.

Of course -- a *new* fox and hound would probably cost you as
much as your color-coded fifty conductor cables, depending on length.
(25-pair phone cable would work and be cheap -- except that it is solid
wire, and not good for use where there is vibration.)

Do you have a digital multimeter? If so, does it have an audible
beeper for continuity checks? Then -- just run a long wire from one
side to the other end and have someone else handy to move that end while
you are at your end. That should use low enough voltages and currents
so it won't harm anything.

Good Luck,
DoN.

--
Remove oil spill source from e-mail
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---