Lightning

On Thu, 21 Aug 2008 12:48:27 -0400, gfretwell.DeleteThis@aol.com wrote:

>On Thu, 21 Aug 2008 13:58:54 GMT, richardcasady.DeleteThis@earthlink.net (Richard
>Casady) wrote:
>
>>>I am always curious about how a boat takes a hit but I do have some
>>>experience with a lightning rod. I put a 3' copper rod over my weather
>>>station with a pointy stainless steel tip, connected to 2ga copper
>>>wire and terminated in a ground rod (connected to my extensive house
>>>grounding system)
>>>It has been hit twice that I know of and I was about 30' away during
>>>one of them. A mexican laborer was pretty much under it, plastered
>>>against my garage door. Other than the poop reflex we were totally
>>>unaffected.. The steel garage door he was plastered to is bonded to
>>>the same grounding system as the lightning rod as is the wet concrete
>>>driveway I was standing on.
>>>We were fine. The weather station ... not so much ... either time.
>>
>>000 wire and a ten foot long grounding rod, is the customary practice
>>with lightning rods.
>
>
>The 2 ga does an excellent job of routing the shot. My ground
>electrode system is a lot more extensive than a single rod. The proof
>is in the pudding as they say. The only thing I have ever lost is the
>serial port in the PC that hooks to the weather station and that is
>because the weather station signal cable runs parallel to the ground
>wire from the air terminal for about 20'.
>I am a bit embarrassed that I did that but I didn't really think this
>thing would attract lightning so well.
>It should be noted that the PC was connected to my network and nothing
>else was affected. In fact I am still typing on the same PC as we
>speak. The only thing that went was the serial port.
>The last time it took a hit the same thing happened. The serial port
>on the lap top it was connected to wasn't even totally fried. It still
>runs a modem, just not the weather station.
>Next time around I am putting the weather station on a fiberglass pole
>on the other corner of the house but I am keeping the air terminal
>where it is.
>If I was using the RF connection from the weather station I bet
>nothing would have been hurt

The ten foot rod is the one that the electrical suppliers sell. It
isn't the only thing that will work. There is one in the ground under
pole mounted transformers. Has the neutral connected to it. Copper
plated steel, driven in with a sledge. Any kind of metal pipe you have
lying around will work.

Casady

"Richard Casady" <richardcasady.RemoveThis@earthlink.net> wrote in message
news:48bbc49b.63617562@news.east.earthlink.net...
>
> The ten foot rod is the one that the electrical suppliers sell. It
> isn't the only thing that will work. There is one in the ground under
> pole mounted transformers. Has the neutral connected to it. Copper
> plated steel, driven in with a sledge. Any kind of metal pipe you have
> lying around will work.
>
> Casady


Electron beam equipment used in vacuum deposition systems cause all kinds of
spikes on the ground plane due to high voltage arcing. (They operated at
10kv dc) The common practice for grounding is two, eight foot copper clad
steel rods, driven about 10-12 feet apart from each other.

Then, a solution of water and copper sulfate is poured along side the rods
and into the holes until an ohm meter reads one (1) ohm or less resistance
between the two rods. Almost impossible to accomplish, but it provided an
"out" for any complaints you might have to the electron beam power supply
manufacturer. Their first question would be "Did you establish a ground
plane as outlined in the manual?". If no, or only close, they were never
much help in resolving any problems.

Eisboch