Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!ames!henry.jpl.nasa.gov!elroy.jpl.nasa.gov!jato!jade!morris
From: morris@jade.jpl.nasa.gov (Mike Morris)
Newsgroups: sci.electronics
Subject: Re: Lightning protection
Message-ID: <1827@jato.Jpl.Nasa.Gov>
Date: 28 Sep 89 20:41:08 GMT
References: <11561@burdvax.PRC.Unisys.COM> <7600025@hp-lsd.COS.HP.COM>
Sender: news@jato.Jpl.Nasa.Gov
Reply-To: morris@jade.Jpl.Nasa.Gov (Mike Morris)
Lines: 47

(David Geiser) writes:
>In hp-lsd:sci.electronics, bam@PRC.Unisys.COM writes:
>b>
>b>The first time it got nailed, the pulse also took out the surge
>b>protector.  I discovered (too late) that surge protectors can only
>b>deal with the first 200-300 volts of a spike. I didn't bother
>b>buying another one.
>
>   Cheap ones, yes.  I've seen used better ones.

Read Jerry Pournelle's column in the August Byte, somewhere around page
100.  Some clown hit the power pole that feeds his house and dropped a 16kv
feeder into one side of the 220...  "Incandescent light bulbs exploded"...

Anyway, due to his experience, I compared the guts of a Tripp-Lite Isobar,
and the common "surge supressed" outlet strip.  There are several heavy-duty
toroidal chokes and capacitors in an Isobar, vs 3 metal-oxide-varistors in the
cheapies.  in fact, I recently found a bunch of 140v MOVs in surplus and added
them to the standard strips I already had.  The Isobar is also built with 
good components, and put together like the proverbial tank - no snap-together
plastic here - it's all metal and screws.

Due to the above, I've bought 3 of the 8-outlet Isobar units for my computer
room (IMSAI, DG Nova 4, PClone, Kaypro, LAN Server, four printers, three
terminals, two modems, speakerphone, 12v power supply for the ham radio 
and packet unit, etc.  I have an additional two cheap strips (with the added
MOVs) plugged into the Isobars - one switches the IMSAI and it's drives on
and off, the other handles the DG Nova 4 and it's peripherals.

The PClone, modem and two printers are plugged into a Computer Associates
Power Director/surge supressor, and the modem line is too - I've got the
model with the supressors for the phone line.  The CA Director is the first
one I purchased, more for the switching than for the supression.  One switch
is very stiff, so I use it for the external hard drive box, so it gets left on,
but I now try 'em before I buy 'em.  If I could find the paralell printer 
spooler for the CA Director at a good price...

Another 8-outet Isobar is going on the TV/stereo system RSN.  I don't need
an exploding TV, or VCRs, or ...    One gentleman I know has a CA Director
on his stereo system - the switches make it very nice...



Mike Morris                      UUCP: Morris@Jade.JPL.NASA.gov
                                 ICBM: 34.12 N, 118.02 W
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