Ethernet and Power Cables

[Rene]

I was told that it is not a good idea to run a power (120 AC) cable together
with an Ethernet cable because the AC cable would disrupt the transmission
on the Ethernet cable.



Is this true? If tit is, is there a way to have the power cord shielded so
that it does not bother the Ethernet cable or vise versa? Can I buy cables
that already include a shield on them?



Thank you.

 

[Jack// ani]

"Rene" <nospam@nospam.nospam> wrote in message news:<qvUed.522650$8_6.77461@attbi_s04>...

I was told that it is not a good idea to run a power (120 AC) cable together
with an Ethernet cable because the AC cable would disrupt the transmission
on the Ethernet cable.

My ac cable and the utp ethernet cable are running one upon the other,
although this is not considered a good practice, but believe me; I
never noticed any disturbance yet.

Can I buy cables
that already include a shield on them?

Then go for a stp cable.

 

[Rene]

Electrical code does not permit power and low voltage signals to run in
the
same conduits or channels. Shielded or not.

Not even if power is only 12 volt DC?

 

[w_tom]

Changing currents of how much will induce what frequency on
adjacent CAT5 wire? Junk science is widespread and prolific
when we forget to apply numbers to our theories. Please
provide numbers for these fields generated by changing loads
on a 12 VDC wire. With those defined fields, what sort of
voltage and current is induced upon twisted pair CAT 5 wire?
Anything is possible in a fiction world where we fear to
provide numbers. Numbers provide a perspective called
reality. What are those numbers?

Jamie wrote:

That is fine how ever, pulsing loads on the DC line could
induce cross talk problems in crappie communication cables like
CAT5 and the like over a long hall.

 

[w_tom]

Don't even worry about shielding. That is 60 Hz field -
very low frequency - induced on tightly twisted pair wires.
Almost no coupling exists. Furthermore any minuscule currents
induced on the CAT 5 wire are made irrelevant by baseband
signaling equipment (NICs) that operate in megahertz
frequencies. What he failed to provide are numbers - the
perspective that makes the problem "insignificant".

Others have defined a more significant parameter - human
safety. Power and communication wires must have some
separation for human safety reasons. Once that necessary
separation exists, then coupling is made even less significant
than "insignificant".

Rene wrote:

That is fine how ever, pulsing loads on the DC line could
induce cross talk problems in crappie communication cables like
CAT5 and the like over a long hall.

Even if the CAT5 cable is shilded?

 

[peterken]

Changing currents of a specific frequency on one line will induce induce
identical AND harmonic frequencies onto the other.
The level of induction depends upon the distance between the lines
(reverse-square of the distance)
The intent of "twisted pair" is to have an induced current to be identical
in both wires, thus (theoretically) eliminating a voltage-difference between
both wires of one loop.
Thus the level of induction depends upon the size of the "spike" in one line
AND it's actual frequency AND the "not-perfectness" of the twisted pair AND
the distance between the line and the twisted pair....

One can of course take the datasheets of a specific twisted pair and begin
calculations until your hair turns grey, but that was not the point of this
thread.
The point was to inquire if power lines could be aside datalines and what
were contra-indications to do so, nothing else...
Personally i prefer to leave the math to the designers of the cables, and
just apply "rules of best craftmanship"....

<quote: One can be born silly, then rocked daft in the cradle, and still
study until completely nuttyness arises....>


"w_tom" <w_tom1@hotmail.com> wrote in message
news:417D5A98.2DDD5960@hotmail.com...

Changing currents of how much will induce what frequency on adjacent CAT5
wire?
Junk science is widespread and prolific when we forget to apply numbers to
our theories.
Please provide numbers for these fields generated by changing loads on a 12
VDC wire.
With those defined fields, what sort of voltage and current is induced upon
twisted pair CAT 5 wire?
Anything is possible in a fiction world where we fear to provide numbers.
Numbers provide a perspective called reality.
What are those numbers?

Jamie wrote:

That is fine how ever, pulsing loads on the DC line could
induce cross talk problems in crappie communication cables like
CAT5 and the like over a long hall.