From: altheimm@nextnet.csus.edu (Murray Altheim)
Newsgroups: alt.pagan,sci.electronics
Subject: Re: Thunderstorms   (was: Re: Night and Winter)
Date: 6 Oct 92 16:00:07 GMT
Article-I.D.: csus.1992Oct6.160007.10130
Organization: California State University Sacramento

In article <1992Oct6.032551.26918@oucsace.cs.ohiou.edu> bwhite@oucsace.cs.ohiou.edu (William E. White ) writes:
>In article <2AD0E0AD.21246@news.service.uci.edu> cortese@skid.ps.uci.edu (Janis Maria Cortese) writes:
>>In article <BvM9nK.4M6@ddsw1.mcs.com> karl@ddsw1.mcs.com (Karl Denninger) writes:
>>>Lightning is one of those things you really can't protect well against.
>>Yes, you can.  If an electrical storm comes up, GET OFF YOUR COMPUTER
>>AND UNPLUG THE DAMNED THING.
>>Just unplug everything you can.  Nothing is better protection than that.
>
>Actually, I've always wondered if it wouldn't be feasible to place some
>sort of "physical interrupter" in line off the main breaker box leading
>to a satellite box, which fed all "sensitive" equipment.   The interrupter
>I tend to imagine would be a lot like a big, motor/solenoid driven switch
>which would break the circuit and insert a dielectric (or maybe two layers
>of dielectric around a ground bar) ... sort of like (on one pole):
>                                              ---
>
>        ====== --- ======              ====== XXX ======
>               XXX
>           (switch on)                   (switch off)
>
>The real questions are, 1) would this work, and 2) would it be realistic
>from a cost point of view?  Obviously for installations with a lot of
>equipment, some form of isolation system would be better (I knew one
>person who used a motor and generator coupled with a fiberglass drive
>shaft, but he lived in a very lightning prone area and probably owned
>more computer equipment than Cray Inc. and the NSA combined).
>But for the average homeowner who uses electronic equipment and can deal
>with interruptions during electrical storms, this sure seems a lot more
>convenient (and probably safer) than running around yanking plugs all
>the time.
>
>Comments?
>
>>Blessings,
>>Janis 

(Excuse me while I put on my mad inventor lab coat...)

Because lightning can jump distances and is very unpredictable, the only
thing I can suggest is to give it the BEST conductor to ground that you
can. If I may make a suggestion, I've never tried it but it would only 
cost about $30, and would probably work. I stress probably.

To use the symbols already given, what I propose is two switch boxes on
your input line, separated by at least three or four feet. These are
standard 220volt on/off make/break switches, with the "pull-out" type
connection switch. Buy two identical switches, and discard (or store
away) one of the switch inserts for safety (so that you CAN'T connect
both at once). Install the first to make/break the 220v into the house,
and the second to ground your entire line to an earth copper rod.

When you break the 220v switch, you insert the switch insert into the 
switch to connect the ground. Hence, both can never be turned on at the
same time, and when your house wiring is not in service, it is grounded
just after the point it comes into the house. The distance between the
boxes is the maximum distance lightning could jump onto an already
grounded line, probably not a problem at that point. Note that supplying
a place for it to jump TO might be a good idea, it just (obviously) can't
be a physical connection between 220v live and ground. Maybe a second
copper rod within a few inches of the 220v live wire. I don't know much
about building codes (and I suspect there is a minimum height), but 
locating the boxes "near" the ground would allow the lightning to reach
ground rather than jumping onto something else.

        ====== --- ==============================================
               XXX                   |
        (220v Mains switch)          |        (line into house)
                                     |
                                    XXX  (Grounding switch)
                                     |
                                     |
                                     V
                                     V   (Copper ground rod)

Of course, messing with 220v is very dangerous if you don't know what 
you're doing, and ANY installation MUST be done with the power turned off!

Safety first! And please remember, this is only a suggestion. I take no
responsibility for this suggestion, so talk it over with an electrician
and have them do it if you aren't the experimenter type.

And above all, ENJOY your storms!

Murray

-- 
Murray M. Altheim      "Ils ont l'orteil de Bouc, & d'un Chevreil l'oreille,
Instructional Consultant    La corne d'un Chamois, & la face vermeille
CSU, Sacramento          Comme un rouge Croissant: & dancent toute nuict
altheimm@csus.edu       Dedans un carrefour, ou pres d'une eau qui bruict."
Newsgroups: alt.pagan