On Sun, 14 Jun 2015 19:39:36 -0500, "dusty " <dustyŽ.net> wrote:
>How close to power lines in the attic can network cable be without causing interference.
I vaguely recall that NEC requires 2" separation between signal and
power cables for safety. I'm not sure of the 2" and am too lazy to
look it up.
If you're worried about coupling between the 60Hz power lines and the
CAT5e network cable, everything depends on the distance that they run
in parallel. If it's fairly short, or the cables simply cross,
there's no cross coupling. However, if you're running something like
50ft next to each other, expect problems.
In theory, ethernet is immune to low frequency (60 Hz) interference.
In reality, the power lines contain substantial amounts of higher
frequency noise and junk that MIGHT couple to the ethernet cable. The
common mode rejection of the twisted ethernet wires dramatically
reduces coupling, but if sufficiently strong, you may have problems.
For example, if you're wiring a factory full of sewing machine motors,
you should certainly keep the network cables away from the power lines
as the variable frequencies, high power levels, and high noise levels
from these motors can cause problems.
You really should ask this question in one of the wiring newsgroups,
such as comp.dcom.cabling.
--
Jeff Liebermann
je...@cruzio.com
150 Felker St #D
http://www.LearnByDestroying.com
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