newbie lightning protection?

walt

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Jun 1, 2007
3,511
Macgregor 26S Hobie TI Ridgway Colorado
Apparently, back then, there was great disagreement between people who believed that lightning rods should have balls on the ends & people who thought that lightning rods should have points on then ends. The rods with the balls got struck more often & therefore were thought to better attract the lightning if your plan was to run a big wire from there to ground.
JiminPB, if you want to look into this more with some fairly recent reasearch, search for a particular paper by Dr. William T Rison. He was at either Sandia or UNM.. but these guys did an experiment with both sharp and blunt lightning rods all placed sort of close together at the top of some mountain. All the rods were grounded. They found that it was the blunt rods that got struck by lightning (making them the better lightning rod) compared to sharp rods. Been years since I looked at that paper but the reason they gave for the difference in getting stuck had to do with the electric fields and corona currents at the top of the pole and how that influenced creating an upwards leader. Apparently the blunt rods are better at creating the upwards leader that meets up with the downwards leader. Very interesting paper if you can find it..
 

Kermit

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Jul 31, 2010
5,657
AquaCat 12.5 17342 Wateree Lake, SC
My pine tree seemed to be properly grounded. We found bark on my roof and across the street in 3 neighbors’ yards. I guess my house wiring didn’t act as a faraday cage for my electronics, either.
 

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Feb 14, 2014
7,418
Hunter 430 Waveland, MS
I guess my house wiring didn’t act as a faraday cage for my electronics, either.
Now you got it! That tree was better grounded than you house and somewhat shielded your house.

But...
The Voltage of the Ground, at the tree base was probably up to 10,000 volts. That High voltage in the ground will run up your Power meter Grounding wire , making all your House grounds, guessing at least 600Volt in reverse, before it would melt your house Panel wires.

When I hear Lightning hit my house, I ask "How big was the hole in your roof?"

No hole and burned electronics...
Back Voltage

Jim...
 

Kermit

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Jul 31, 2010
5,657
AquaCat 12.5 17342 Wateree Lake, SC
It definitely hit the tree. Weird things happened inside. The breaker for the garage door opener was not just tripped but turned completely off. The circuit board for the opener got fried. Only one nightlight blew out. Every HDMI port in the house was fried. That’s two TVs and the one on my computer. Also the network input on the computer was ruined but it didn’t ruin the computer. The only burn marks we ever saw were on the garage door opener circuit board. All in all I’d say we got pretty lucky.
 
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May 12, 2004
1,505
Hunter Cherubini 30 New Port Richey
At first, I thought this was just a joke. Interesting. Now, how 'bout fishin' with grenades? :eek:
 
Aug 31, 2011
243
Catalina C-22 9485 Lake Rathbun, IA
Having been hit by a giant bolt of electrical discharge last year, wiping out every electronic device on board, I favour science (electrical eng. and statistics) then remedial options 2 and 3. Much is written on the subject. Google is aglow with articles, as is this forum. Some say that any form of grounding conduit can and may cause additional harm, even sinking the vessel.

Maybe I was lucky. Marina caught the act on security footage. Dock worker observed from no more than 100m away. Spectacular he said !! It was impressive. Wish I had a copy of the video to share.

Hit the top of the stick, traveled all the way down, dissipating via every electrical cable possible, and best guess exited via the motor (tip still in water) or the keel. Best bet was motor as no burn marks on the keel trunk or any fibreglass for that matter. Oddly, did not cause damage to motor or electric start. But fried the stereo, marine band radio, GPS plotter, battery charge controller (melted) and every fuse. St.Fm Insurance covered the whole thing, no questions asked (pictures and receipts helped). $100 deduction. Check your policy.