Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!uunet!ingr!b11!goodloe
From: goodloe@b11.ingr.com (Tony Goodloe)
Newsgroups: comp.dcom.lans
Subject: Re: Grounding Ethernet coax lines.
Message-ID: <6168@b11.ingr.com>
Date: 11 Oct 89 16:21:54 GMT
References: <3824.25292578@zeus.unl.edu> <2128@avsd.UUCP> <27682@amdcad.AMD.COM> <2140@avsd.UUCP>
Organization: Intergraph Corp. Huntsville, AL
Lines: 21

In article <2140@avsd.UUCP>, childers@avsd.UUCP (Richard Childers) writes:
> Hmm. The thin ethernet cables I'm familiar with all have two ends. Neither
> end is distinguished from the other. Both have the coaxial braid firmly
> attached ( grounded ) to the connector ... I don't see how you could only
> ground it ONCE. It has to be connected to two devices.

Only one end of the coax may (and should be) tied to "earth". If you do
ground it in more than one place you set yourself up for ground loops. I
think part of the national electric code (I'm sure I'll be
corrected if I'm wrong :) allows only one end to be grounded.

> I can see how that might be a problem, but that would seem to require that
> the equipment be grounded, separately.
If the equipment is in different parts of the building it probably will
be using different grounds.

> ( In any case, I don't think ethernet
> belongs between buildings, I think that's a job for fiber optic. )
can't say that too loudly!

tony goodloe