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From: rvdm@oce-rd2.UUCP (Ruurd van der Meer)
Newsgroups: net.lan,net.dcom
Subject: Ethernet DAMAGE by hazardous voltages (e.g. lightning)
Message-ID: <84@oce-rd2.UUCP>
Date: Wed, 27-Nov-85 11:26:34 EST
Article-I.D.: oce-rd2.84
Posted: Wed Nov 27 11:26:34 1985
Date-Received: Fri, 29-Nov-85 21:41:11 EST
Organization: OCE R&D dept., Venlo, The Netherlands
Lines: 35
Xref: watmath net.lan:1173 net.dcom:1507


I am wondering what measures can be taken to avoid  x-million 
dollar damage by lightning on local network cables like 
Ethernet.
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The standard says : the shield conductor of each coaxial cable
segment shall make electrical contact with an effective EARTH-
reference at ONE point. A lightning on the other side of the
segment can destroy a lot of interface units and possibly more.
We at OCE have a lot of buildings with Ethernet in between.
An expensive solution is using optical ways to seperate.

I know there are 'spike-' or 'surge-' suppressors to be put
in coaxial cables. The one I know are for IBM (93 ohm) cabling.
Does anyone know such suppressors for Ethernet cable (50 ohm) ?
What about reflections with these suppressors ?  

All ideas to avoid lightning problems on networks are welcome!

		Ruurd van der Meer  OCE  NEDERLAND  BV
				    Netherlands// Venlo

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