Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!ncar!ames!coherent!dplatt
From: dplatt@coherent.com (Dave Platt)
Newsgroups: comp.dcom.modems
Subject: Re: Lightning Protection (WAS: Modem encountering power spike)
Message-ID: <32722@coherent.com>
Date: 7 Sep 89 17:46:31 GMT
References: <9645@b-tech.ann-arbor.mi.us> <210@tabbs.UUCP> <9649@b-tech.ann-arbor.mi.us>
Reply-To: dplatt@coherent.com (Dave Platt)
Organization: Coherent Thought Inc., Palo Alto CA
Lines: 43

> >What kind of lightning protections ACTUALLY WORKS?  I mean, you've heard
>
> One one phone line I have a fairly cheap ($15) thing from Radio 
> Shack.  On the other I have a fax protector (similar to the ones made 
> by Isobar).  I haven't had a problem on either line since installing 
> these.  

Check out Jerry Pournelle's tale of woe in the August issue of Byte
(page 99).  A car clobbered a power-pole in his neighborhood, and
apparently dropped the 16k-volt distribution wire onto one side of the
220-volt local feeder wire.  "Not only did the lights go out, but they
instantly came back on for a brief moment, and this time there were
sparks and bright flashes all over the room.  A light bulb exploded.
There were more flashes outside.  Then quiet, and darkness."  The damage
was severe.  Every incandescent light that had been turned on at the
time, was burned out; two bulbs exploded.  The power surge "... killed
every unit of electronic equipment that was turned on and not plugged
into a surge suppressor."

He had at least three different brands of surge-protector in use at the
time.  An Isobar "Power Isolator and Surge Protector" successfully
protected the PC and laser-printer into which it was plugged, but died
in the process... its MOVs melted and shorted, and its choke-coils were
clearly overheated.

A Priam hard disk connected through a Woods surge-suppressor died... its
fuse filament was completely vaporized, and the power supply was
toasted.  "The Woods suppressor might as well not have been there."

"Quite a lot of equipment was plugged into CompuGuard surge suppressors
I had bought on sale from Priority One.  Not one unit of any kind
protected by a CompuGuard was harmed in any way."

Equipment plugged into a Clary UPS "didn't even glitch."

It sounds as if Isobar and CompuGuard are well-designed AC-line surge
protectors;  if their phone-line suppressors are of similar quality,
they'd be well worth using in lightning-prone areas.
-- 
Dave Platt    FIDONET:  Dave Platt on 1:204/444        VOICE: (415) 493-8805
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