[Tfug] Switches -- and hubs!

Louis Taber ltaber at gmail.com
Thu Jan 7 11:41:45 MST 2010


Yep, a nearby lightning strike can push up the common mode voltage.  The
little Ethernet transformers should be good for at least several hundred
volts.  I did find this with a quick web search:
ANSI X 3.263 standards including 350u H OCl minimum with 8mA bias, 1,500Vrm
minimum isolation
Have you ever tried to pull terminated fiber through 1200 feet of conduit?
I broke the fiber at the connector once when I was pulling about 30 feet.


On Thu, Dec 31, 2009 at 9:27 PM, Bexley Hall <bexley401 at yahoo.com> wrote:

> > The location is in Northern California near the coast.
> > Unlike Tucson, Lightning is rarely an issue.  Base-T
> > Ethernet does have isolating transformers at both ends of
> > the run, so ground loops are not an issue.   Lighting can
>
> Yes.  Though you still have to worry about common mode
> voltages.  Note that this also applies to the DC-DC
> converters in your PoE devices...
>
>
> > The problem with fiber, as almost always, was the
> > termination.  How do you get some one 25 miles from a small
> > town to put the connectors on the cable.
>
> Simple!  Live in the LARGE CITY located 25 miles from that
> "small town"!  :>
>
> (couldn't buy preterminated lengths?)
>
>
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