Never in a house BUT ...
A church we use to attend used it when a new building (larger than the old
structure) was added on. A new service panel was placed in the new section
and some HEAVY twisted cable was run to the original service panel. (I
don't know whether the "old" panel was wired with neutral separate from
The work was done by a member of the church but he was a licensed
professional with plenty of experience on commercial and residential work so
I guess it was legal. Certainly any reasonable inspection would have
It wasn't in conduit. The only protection was the insulation on the
| hfs2 wrote:
|> |> Has anyone seen a house wired with twisted pair?|> Does code allow it? Is large guage wire (10 - 12 -14)|> even available?
| Unjacketed twisted pair? No.
| I have seen some NM cable in which the conductore were twisted.
Service drop cable is twisted. It hasn't seemed to cause anything funny
to happen to the electricity, like making it spin.
| Phil Howard KA9WGN | http://linuxhomepage.com/ http://ham.org/ |
There is nothing wrong with twisting conductors unles the pitch is so
short that the twist adds some conductor length. Even then, the effect
would be minimal.
I think the OP was wondering if twisting conductors would cancel
coupling to adjacent circuits. The answer is yes, to a degree. If a
sensitive circuit was run adjacent to a branch circuit, twisting both
will decrease coupling.
Paul Hovnanian mailto: snipped-for-privacy@Hovnanian.com
For 50/60Hz power it won't have any practical effect, though it
probably could be measured (with effort).
Twisting the pair improves balance, so the degree to which
balance improvement helps is what counts. At 50/60Hz the
difference between twisted and non-twisted cable would be hard
to measure until the length far exceeded typical distances
likely to be found in household power wiring (a few hundred
But as far as using the power cable for other services, such as
broadband data networking, yes it would have an effect. It
would increase the distance over which such a network will
function. Probably not greatly, but it might be just
significant enough to allow a transmitting device to be at one
end of a building rather than requiring it be in a more central
location to shorten the distance to the most distant receiver.
Twisted pair would have the effect of minimizing but not eliminating
the electromagnetic fields that are associated with current flow.
The principle is used in microphone, line-level audio, and telephone
circuits to minimize radiation and adjacent coupling to similar
For practical electrical wiring though, the downsides outweigh the
advantages. Pulling large conductor twisted pair wire though conduits
for example would be difficult and require additional labor. There
might be some derating to increased heat that has nowhere else to go.
In the early years of this century, appliance power cords were often
Um, that's fine, but my question related to the assertion that the
electricity doesn't start spinning. Before one can be certain of this,
one needs to know what one would see if it did, in order to be able to
infer anything from the absence of the observation.
Not that I was being that serious.
Well sometimes, being that serious can be a good thing...
The engineers and technicians that frequent this newsgroup like
precise definitions, based upon the accumulated knowledge of the
measurements and observations of physical phenomena.
What do you mean by spinning? It is difficult to describe electricity
scientifically. In super simple terms, it is the flow of electrons in
a conductive material. It is also characterized by magnetic and
electrical fields that may occur at a distance from the conductive
Magnetic fields in parallel conductors with opposite, but equal
currents will tend to cancel each other out, but not completely.
Twisting the conductors merely alters the spatial relationship of the
residual fields so that they will occur in a circular (or more
properly) a spiral track.
You could argue that the electricity is spinning in the same sense
that the electromagnetic fields in an AC motor are spinning...
Since this type of "army" wire has about 50 twists per meter you could say the
electricity was spinning at about 900 million RPM. It's lucky that the stuff
coming back is going in the opposite direction and nulling out the field or it
would pull all of the nails out of the wall. ;-)
What's the mass of the field? The electrons themselves do not move very
fast at all. You could imagine doing this experiment with a just one of
the twisted conductors in use. What would you see? Not much, I suspect.
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