Lightning rod?

[fishheadbob]

I used to live near a television broadcast tower. During a big storm we would crack a cold one then sit in the window watching the tower get hit repeatedly, looked like a scene from Frankenstein, never saw anything wrong with that channel's reception so I figure someone knew what they were doing when that tower went up in the 1950s. We took a look at the tower a few times over the years, the thought struck me that the whole steel tower and all of the supporting guy wires were essentially one big lightning rod that did the job properly.
I have rods on my house and barn that were installed before I was born, judging from the noise and hair raising static I'd guess mine have been popped a few times with no ill effects.
Some people seem to draw lightning more than others. I believe the golfer Lee Trevino has been struck a few times, but I would check that statement out. My wife has been around 3 near misses, most involving water lines. She heads for the basement during a big storm; my great aunt was the same way.

 

[Groo]

Think I'll give it a pass. If something happens now, It'll be on the insurance. If I mess with things and something happens, they might try to blame my meddling.

 

[Fuddy1952]

I was an electronic technician 43 years, retired over 4 years ago. All I know is growing up the two houses on hill top got hit all the time even blowing chimney off. Then lightning rods on everything 60 years ago and not 1 single hit.
In college one instructor said you can't arrest lightning, millions of volts and maybe 50,000 amps for a few milliseconds. Direct strike would vaporize almost anything.
We're close to Thomas Jefferson's Poplar Forest home where they put lightning rods in the big oak trees.
My house is old but in the 60s they put aluminum siding on it, there when I bought it in 1980. It was grounded, I never had a problem... I had it removed, vinyl siding put on late 80s then had problems.

 

[PILOON]

I did a few microwave tower installations for Hydro Quebec years back.
The ground plane called out used many coils of # 6 bare wire in about a 30-50 ft radius all soldered together at the center.
OK that was for electronic 'ground plane' but also served at lightening grounds.

Wet conducts and in absence lots of copper in contact with the earth is needed.

 

[Larry Caldwell]

They simply provide a controlled path (in theory) to ground when a strike occurs, provided they are installed and connected correctly.

That's one way they work. A lightning rod should be sharpened to a point. This results in a very high field gradient around the point, causing corona discharge. In theory, the corona discharge will bleed off the strike before it happens. If a strike still happens, the charge will bleed to ground on the ground wire. A lightning rod does not have to be attached to the house to provide protection. A nice flag pole in the yard is a great place to put one.

 

[Larry Caldwell]

Well, I don't mind saying I'm confused.

So rods dissipate the charge, yet high sky scapers and towers get hit all the time.

A hit can melt a 6 AWG cable, yet grounding systems take hits all the time without damage.

And what of steel roof buildings that are not grounded intentionally and probably only have electrical grounds nearby that never seem to get destroyed if the roof were to get hit and the charge jumps to the nearest electrical line.

I was looking at a pole barn when it took a lightning strike. It was a shower of little lightning bolts all around the building, but the building itself took no damage.

 

[Larry Caldwell]

Yes, grounded systems do drain and prevent static charge buildup, and all things connected are equalized (to ground); but I don't understand how that would prevent a lightning strike. It's the cloud that gets charged up to a huge differential (as compared to the earth), and once the rain drops and anything else conductive provides short enough gaps that the arc(s) can jump to ground: boom!

It's all because old Ben Franklin guessed wrong about the direction of current flow when he discovered lightning was electricity. Lightning bolts do not come down, they go up. The ground is the negative charge with the excess of electrons. Lightning rods only dissipate the excess electrons if they are sharpened to a point.

St. Elmo's fire - Wikipedia

 

[Industrial Toys]

I was once shown lightning rods from OPP towers. They were melted and it was a common thing to replace them.

Most of my amateur UHF/VHF antennas are all DC ground. Very robust and to someone who did not know RF, you would be hard pressed to understand how it would work. It looks like you just bolt this heavy tubular structure to the tower without insulators. Anyway, those antennas are great for lightning.

Then I have this hammy Hamster broadband DISCONE antenna. Once in the approach of a storm I noticed sparks flying across the PL259 Connector. Now, I always try and disconnect the radio attached to it if expecting a storm.

 

[RalphVa]

I live in a relatively flat wooded area. I moved here late last summer. So far this year I've had 2 lighting strikes on trees in my yard. Would a lightning rod save the house? Or just make sure it is the house that gets hit? I was considering getting a standing seam metal roof for the place. Would that change the equation?

I was typing a reply to this a couple hours ago when our power went out AGAIN. Apparently, lightning hit something in the area and knocked out our power and internet (and often our phone).

First thing we did when we bought this house was to have lightning protection installed. Then expanded it to the carriage house when we had it built.

The 2nd house on our road had its chimney all over the road when we came in here looking. Saw another chimney in another neighborhood that was crooked because it had been hit. Figured we needed lightning protection in Virginia.

No hits in 18 years. Of course, we just had a record Ivy Creek flood that made a mess of our property down on the creek, worse than Isabel in 2003. Hope the lightning stays away.

Ralph

 

[Fuddy1952]

I was typing a reply to this a couple hours ago when our power went out AGAIN. Apparently, lightning hit something in the area and knocked out our power and internet (and often our phone).

First thing we did when we bought this house was to have lightning protection installed. Then expanded it to the carriage house when we had it built.

The 2nd house on our road had its chimney all over the road when we came in here looking. Saw another chimney in another neighborhood that was crooked because it had been hit. Figured we needed lightning protection in Virginia.

No hits in 18 years. Of course, we just had a record Ivy Creek flood that made a mess of our property down on the creek, worse than Isabel in 2003. Hope the lightning stays away.

Ralph

Howdy Ralph! You're a Hall living in Virginia and so am I. Could we be kin?

 

[Industrial Toys]

I still don't know what to make of people that proclaim they just LOVE a good thunderstorm!

 

[Fuddy1952]

Oh...this is how I got on roof today. In 90s so I couldn't do much. I did manage to run braided copper wire chimney to chimney then down to ground rod. I tucked flat cable under roof cap shingles as I went along.
Near ground rod I have a big fake rock to cover a Malibu light transformer. Yes there was a big 'ol black snake under there.

 

[Industrial Toys]

I hope you went down each side. I believe that's important to form as much of a cage as possible.

Snakes make me very uncomfortable. But I hope you were nice to it.

Funny. My Lady friend just called. We spoke about the heat and lack of rain. Wouldn't she just go and say, she just loves a good thunderstorm. I said, good, you can pay for the stuff that gets destroyed!

 

[tallyho8]

In my last home before I moved here, lightning struck the power cables while I was watching TV. A flash came out of an electric outlet in the room and afterwards I discovered that my doorbell transformer was blown, the timer in my washing machine was burned out, my refrigerator defrost timer was blown and one telephone suffered a meltdown. It seemed that only things with very small wiring had been damaged.

Another time I was out coonhunting at night when a thunderstorm came up. Just after I removed my light and batteries and opened the door to my truck, my hair went straight up as pulled by static electricity. I dove to the seat of my truck and saw a bright flash but heard nothing. When I got up a few seconds later I saw the tree next to my truck smoking with branches missing and a big split down the side. I never figured out why I did not hear anything.

Last year my electric fence was hit ruining the fence charger, the 8x8 post it was on and the electric outlet and about 3 feet of romex going to the outlet. In the last 13 years since Katrina I have had about 20 of my large trees destroyed or damaged by lightning and I am losing trees faster than they can grow back. South Louisiana has more thunderstorms than just about any other part of the country but they seem much worse in the last 20 years than ever before.

That being said I still love to sit back and gaze out the windows during a lightning storm watching the show and I still feel safe inside my home.

 

[bigtiller]

If current flows from negative to positive, then it makes me want to agree that lighting rods dispel negative electrons and lessening the chances of a strike.

 

[Fuddy1952]

Years ago when I had aluminum siding replaced with vinyl I started having lightning problems, sparks out of outlets, every light bulb popping. I called my insurance company who recommended a company to take tv's, stereos, etc. to which turned out to be my company. That was strange.
Some people after a lightning strike thought they won the lottery. Fact is most electronic things depreciate and aren't worth much.
After I put a whole house arrestor on the main panel box I haven't had trouble.

 

[Industrial Toys]

Consumer stuff isn't worth much to begin with. I just heard of a scandal in Germany about how much return merchandise Amazon destroys every day. IF I recall, it's in the millions. The point is, that CONSUMER JUNK isn't worth much at all.

 

[Tractor Seabee]

In my early days as a HVAC/Refrigeration Tech I was working on an AC unit on a roof when lightning hit in the area. It jumped around to many metallic items such as teh AC, TV antenna, and plumbing stacks (back then they were iron or steel), it blew me off the roof but no damage to me from the lightning (as far as I know). Scared the S*** out of me though and hitting the ground (10' down) was the trauma part. No damage to the AC unit but a plumbing stack was blown away above the roof; that was probably ground zero. Climbed back up to the roof and finished the job. Oh, this was in Scottsdale AZ.

Ron

 

[techman]

Another time I was out coonhunting at night when a thunderstorm came up. Just after I removed my light and batteries and opened the door to my truck, my hair went straight up as pulled by static electricity. I dove to the seat of my truck and saw a bright flash but heard nothing. When I got up a few seconds later I saw the tree next to my truck smoking with branches missing and a big split down the side. I never figured out why I did not hear anything..

This is not uncommon. Prior to many lightning strikes, the static voltage in the air can reach several hundred volts per meter above ground. There are many reports of peoples hair standing up just prior to a close strike. In these conditions lightning rods and other devices to bleed off the static charge in the air can help to prevent a strike in that area.

paul

 

[Ritothebull]

I recently had the power company change my service from above ground to underground because the line came through the woods and it was cheaper to bury it than constantly deal with all the trees. When they installed the transformer they drove in a 30' ground rod, when I mentioned that most home rods were only in 8' they said that they probably won't work.