Beachcomber wrote:
Thanks. I do not understand what's wrong with putting cat5e cables
next to electrical conduits (we have metallic conduits), but the rest
makes sense to me.

i


Here's a tutorial that perhaps might explain some of the restrictions.
If you tied your cables to electrical conduits for any significant
length, it might still work but it could fail certification.

http://www.lanshack.com/cat5e-tutorial.asp


From a physics standpoint, what you are concerned with is
electromagnetic shielding. A grounded conduit provides nearly 100%
electrostatic shielding, but the currents in the electrical conductors
within produce a dynamic magnetic field that leaves the boundary of
the conduit and is almost impossible to shield or contain.

A few years ago, everyone was concerned about these low frequency
magnetic fields but if was difficult to prove that they caused any
health hazards.

They can and do interfere with communications circuits, though, and
this is why there is a specific prohibition about attatching cat5 to
conduit.


Beachcomber



I may be wrong but, I don't think that's right. That's why ethernet
uses twisted pairs of wires -- so it can reject common mode
interference. A voltage caused by a stray magnetic field would be
equally induced on both conductors of the pair and would be rejected.

Bob