I see people with roof mounted radio and television antennas all the time. Their grounding cables are far, far longer than 10 feet and obviously have bends in them since they are up in the middle of the roof somewhere. So are they begging to get hit by lightning (serious question, no snark)? Is it dumb luck when people have antennas mounted on the roof for years or decades and don't get hit, or are they getting hit and not admitting it?
HF, VHF, UHF, and Grounding
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I see people with roof mounted radio and television antennas all the time. Their grounding cables are far, far longer than 10 feet and obviously have bends in them since they are up in the middle of the roof somewhere. So are they begging to get hit by lightning (serious question, no snark)? Is it dumb luck when people have antennas mounted on the roof for years or decades and don't get hit, or are they getting hit and not admitting it?
Those wires are low impedance. Less than 10 feet is an example of what a 'whole house' protector needs to be low impedance. Eventually wires may have bends. But the bends are always sweeping bends. Otherwise protection is compromised. In properly installed solutions, bends and longer wires are avoided everywhere possible.
Lightning rods never make strikes easier. Lightning will find a best path to earthborne charges maybe four miles away. Either it takes a harmless (low impedance) path to earth via a wire that remains outside the structure. Then it created a near zero voltage. Or it goes inside via high impedance paths, destructively inside. Therefore a high voltage is created.
What makes lightning strikes more or less likely? Geology. Even nearby trans-continental pipelines can make strikes more likely.
Is a mountain top most often struck? No. More often struck is a mountain's side - where soil is more conductive.
A low voltage times 20,000 amps means low energy - no damage. A high voltage times 20,000 amps means massive energy does significant damage. Critical is to make that connection low impedance. Obviously lowest impedance is down a 30 foot tower and not 30 feet through air.
Is it dumb luck? Surges are quite rare. Typically once every seven years. For most, maybe once every 20 years. In places such as FL, maybe as much as one every three years.
Most are incoming on wires that stretch out all over town - AC electric. Incoming to every household appliance. Much less often is one that strikes a structure. Virtually every professional organization recommends what is always required to have protection.
A lowest impedance connection to earth was the Empire State Building. So electronics atop that building suffer 23 direct strikes annually - without damage. Much early research by both GE and Westinghouse was conducted here in the early 1930s. Which is why direct strikes without damage are routine.
Or learn from a case study: Case Study: Florida 911 Center Upgrades Lightning Protection System for Maximum Safety
From the US Forestry Service. Well over 95% of all trees struck by lightning have no appreciable damage. Rare is the tree with serious lightning damage. Just another example of what really happens verse what so many conclusion only from the rare example. Direct lightning strikes without damage is routine when one properly earths lightning rods (to protect a structure) and earths all incoming wires (to avert the more common damage to appliances). Neighborhood history over 10 or 20 years can say more about the risk.
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www dot reddit dot com slash r slash crtgaming slash comments slash 7e0zmv/besides_a_surge_protector_how_else_do_you_protect/dq8qkdf/
www dot reddit dot com slash r slash crtgaming slash comments slash 7e0zmv/besides_a_surge_protector_how_else_do_you_protect/dq8qkdf/
TV antennas that are professionally installed would be done to NEC Article 810, which is for human safety and not necessarily lightning protection. I was once an SBCA certified trainer for home satellite dishes and I knew the NEC to the extent of TV and satellite dishes. Ideally no more than 30ft of 10ga wire from the antenna or dish to the house electrical panel ground. It could be bent or whatever because its not for lightning, its to put the TV antenna or dish and its coax at the same ground potential as the rest of the house so if your TV fails and puts 120v on the antenna lead it won't kill you. If most TV antennas get a direct hit most every appliance in the house will need replacing.
Thank you.
Thanks.
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I wouldn't give up on the subject yet, KPO- but I would sit back after your scientific inquiry and weigh all your odds.
I have dealt with lightning, static, St. Elmo's fire-- you name it-- all my professional life. And in having it presented in so many 'in my face' scenarios, I have become very philosophical about the subject.
Quite a few people in here have given you some good advice- now you have to sift it and decide where you want to take it.
_____________________________________________________________
Extrapolating this to real life:
As a government scientist I work to the standards of perfection (well, usually)- and static suppression
St. Elmo's Fire
is something always high on my lists. Yet anyone following my posts will quickly conclude I take sort of a perverse pleasure in recounting my professional and private lightning/static experiences-- and disasters-- all the perfections be damn'd.
My evolving philosophy about everything Zesus throw that goes "Zap !" is that if he has your number that day, you are screw'd. I have seen how he has laughed at the most harden'd EMP facilities- to ever believe you can be absolute 100% protected... and tho I will no doubt catch flak for saying this, don't let anyone convince you otherwise.
With that being said, always keep in mind that the average household has a virtually zero chance of ever suffering a direct hit- all the popular legends, myths and news stories to the contrary.... but that is, if you don't do sometime to try and attract it...... a 120 foot tower comes to mind.
The real danger you face is from the secondary voltage spikes that will come in to your house over a myriad of paths- from power, telephone, data, cable TV lines- your water and gas pipes- to name a few more exotics. But those paths and spikes you can definitely do something about.
I adhere to what is called a "floating ground."
We use it exclusively at our remote sites. You can read about it in that IEEE booklet I cited earlier. With such a system I feel reasonably certain our equipment will withstand everything except a direct hit.
Okay, I was talking suppression at the big $$ levels. What is a homeowner to do ?
This is strictly Coyote talking now---
After you have done a 'floating ground" about your house al la the IEEE guidelines-- Sit back and stop worrying.
Zesus will see and appreciate your efforts and take is wrath out on someone else.
People have thought me kind'a afflicted, but I have been known to take a bottle of wine outside into the heart of a thunderstorm and offer him a glass (I'm told Zesus likes a pinot noir, but don't hold me to that ) - It never hurts, and I like to think after all these years he and I have come to a peaceful coexistence.
Seriously, do all you can Reasonably do, and then let it go.
An example:
I and some friends own an old mining claim high up in the Rockies. It consists of a cabin above treeline, some out buildings-- all at over 12,000 feet. We can experience St. Elmo's fire practically every time a charged cloud rolls across the surrounding 14' teen'rs and settles into the our alpine cirque. Naturally everything that is metallic is ground'd- stove flue pipe, propane lights-- and it does Reduce the errie displays...
We have radios up there and one is a CB. I have taken a different bend on its static suppression....There is really none.
A large RF choke runs from its base to the "floating ground"- and there is a big aluminium ball that graces its peak... but that's all.
With that modest arrangement we don't get the 'fire' about this antenna, and if by chance it does take a direct hit ?... hey, its a CB radio.
Do what is do-able and then go on and enjoy your hobby, KPO
Lauri
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I wouldn't give up on the subject yet, KPO- but I would sit back after your scientific inquiry and weigh all your odds.
I have dealt with lightning, static, St. Elmo's fire-- you name it-- all my professional life. And in having it presented in so many 'in my face' scenarios, I have become very philosophical about the subject.
Quite a few people in here have given you some good advice- now you have to sift it and decide where you want to take it.
_____________________________________________________________
Extrapolating this to real life:
As a government scientist I work to the standards of perfection (well, usually)- and static suppression
St. Elmo's Fireis something always high on my lists. Yet anyone following my posts will quickly conclude I take sort of a perverse pleasure in recounting my professional and private lightning/static experiences-- and disasters-- all the perfections be damn'd.
My evolving philosophy about everything Zesus throw that goes "Zap !" is that if he has your number that day, you are screw'd. I have seen how he has laughed at the most harden'd EMP facilities- to ever believe you can be absolute 100% protected... and tho I will no doubt catch flak for saying this, don't let anyone convince you otherwise.
With that being said, always keep in mind that the average household has a virtually zero chance of ever suffering a direct hit- all the popular legends, myths and news stories to the contrary.... but that is, if you don't do sometime to try and attract it...... a 120 foot tower comes to mind.
The real danger you face is from the secondary voltage spikes that will come in to your house over a myriad of paths- from power, telephone, data, cable TV lines- your water and gas pipes- to name a few more exotics. But those paths and spikes you can definitely do something about.
I adhere to what is called a "floating ground."
We use it exclusively at our remote sites. You can read about it in that IEEE booklet I cited earlier. With such a system I feel reasonably certain our equipment will withstand everything except a direct hit.
Okay, I was talking suppression at the big $$ levels. What is a homeowner to do ?
This is strictly Coyote talking now---
After you have done a 'floating ground" about your house al la the IEEE guidelines-- Sit back and stop worrying.
Zesus will see and appreciate your efforts and take is wrath out on someone else.
People have thought me kind'a afflicted, but I have been known to take a bottle of wine outside into the heart of a thunderstorm and offer him a glass (I'm told Zesus likes a pinot noir, but don't hold me to that
) - It never hurts, and I like to think after all these years he and I have come to a peaceful coexistence. Seriously, do all you can Reasonably do, and then let it go.
An example:
I and some friends own an old mining claim high up in the Rockies. It consists of a cabin above treeline, some out buildings-- all at over 12,000 feet. We can experience St. Elmo's fire practically every time a charged cloud rolls across the surrounding 14' teen'rs and settles into the our alpine cirque. Naturally everything that is metallic is ground'd- stove flue pipe, propane lights-- and it does Reduce the errie displays...
We have radios up there and one is a CB. I have taken a different bend on its static suppression....There is really none.
A large RF choke runs from its base to the "floating ground"- and there is a big aluminium ball that graces its peak... but that's all.
With that modest arrangement we don't get the 'fire' about this antenna, and if by chance it does take a direct hit ?... hey, its a CB radio.
Do what is do-able and then go on and enjoy your hobby, KPO
Lauri
.
.
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Repeating: code says nothing about protecting appliances. Code is only about protecting human life. A code acceptable connection to earth ground only need be low resistance - not low impedance.
Facilities all over the world suffer direct lightning strikes without damage. Others only speculate that damage is inevitable when they suffer damage; did not learn these well over 100 year concepts, and then make a conclusion only from observation. Protection from direct lightning strikes is so routine that lightning damage is considered a human mistake. Your telco CO suffers about 100 surges with each storm - and no damage. Many previous examples demonstrated that reality.
Another describes what he did. Then direct lightning strikes caused no damage: UFER grounding system
That TV antenna must connect direct down to earth ground. Then its coax cable must route to the service entrance (before entering) so that a low impedance (ie less than 10 foot) connection to that earth ground is bonded. Then direct lightning strikes do not do damage (if that earthing electrode is sufficient).
Code requires a TV antenna ground be bonded to the other earthing electrode. We often do not do that. But a buried bare copper wire interconnecting both electrodes increases protection of all appliances inside the building. Even appliances not connected to that TV cable. Because it expands / enhances what defines all protection - that earth ground electrode.
NEC Article 810 only describes what is sufficient to protect human life. That must be upgraded to also protect electronics. Single point earth ground is essential. That TV antenna wire (and invisible dog fence, underground lawn sprinkler wires, etc) must be bonded to the same earth ground featured in this AC utility recommendation:
Tech Tips - Duke Energy
then select Tech Tip 8.
Code only discusses low resistance to protect humans. That required earth ground cannot be floating. Transient protection discusses low impedance to protect appliances. Workmanship that is code acceptable (ie sharp wire bends, splices, wires inside conduit) are bad for appliance protection. That code acceptable installation creates excessive impedance. For transient protection (including and not limited to lightning), that connection to earth ground must be lowest impedance.
For every residential direct hit story that survived there is probably 100 that have a sad ending with lots of damaged electronics in the house. Personally, I don't know anyone who had a direct hit at their house and nothing was damaged. On the other hand, I know many people who had a direct hit and it wiped out many if not most electronic things in the house.
I've also worked at countless mountain top repeater sites and satellite broadcast centers that have survived a direct hit with no problem. Those were commercial installations with expensive engineering and components meant to survive a direct hit. I also had a friend who was in his basement and was hit in the chest by lightning and they didn't find any other path the lightning took except through a window and through him to the concrete floor. It messed him up pretty bad but he lived to tell about it.
I've also worked at countless mountain top repeater sites and satellite broadcast centers that have survived a direct hit with no problem. Those were commercial installations with expensive engineering and components meant to survive a direct hit. I also had a friend who was in his basement and was hit in the chest by lightning and they didn't find any other path the lightning took except through a window and through him to the concrete floor. It messed him up pretty bad but he lived to tell about it.
jim202
Member
Don't take this attitude. It is not that hard to put your hands around the subject. Just take one step at a time.
Like I had mentioned before, "How old is the house? When was the last time the ground rod under your electrical meter changed out? Ground rods at the electrical meter don't last forever. They do a slow death due to corrosion. The older they are the higher the earth resistance becomes on that ground rod. The higher it's resistance is the less protection it provides. So the first place to start is your ground rod at the meter.
Another question if you plan to replace the ground rod is to take into account the soil where you are. If you have sandy soil, an 8 foot ground rod will not be enough. You might check with the local wiring inspector and ask what length ground rod is acceptable. Sandy soil that is dry, might require a ground rod that goes down as far as 40 feet. If the soil is wet, then maybe an 8 foot length will be enough. If the soil is rocky, your in for a struggle. Your ground rod may have to go in on an angle. and not straight down. It may also require more than on ground rod to obtain a low resistance.
The old electrical wiring in the house that is using the tubes going through the beams does not carry a ground with it. This type of wiring was done long before the NEC was even thought of. Most of the appliances today use a 3 prong plug. That round pin is the electrical ground for your protection. The real old wall outlets only had the 2 slots for the plug. No third pin that provided the electrical safety ground. If you have external surge protectors in use, they can't plug into these 2 prong outlets.
But there is the possibility that someone has gone around the old section of the house with the old wiring and changed out the outlets to the modern 3 prong type used today. If so, pull off the cover and look at the bracket and see if you see a ground wire connected to it. My guess is you won't find the ground wire. So basically you don't have the ground protection on these outlets.
Tower grounding and coax cable entry grounding and surge protection is another whole subject. If you look enough through the NEC, you will find a telecommunications section that allows the antenna system grounding to be connected to the electrical system ground rod. This is done to allow everything at the location to be at the same ground potential. A simple translation is you put in a ground system (multiple ground rods connected together) for your tower and antenna system with the coax cables and tie the ground wire to the electrical earth ground for the building. This allows all grounds to be at the same potential. You will also find the electrical ground wire from the meter to the ground rod is a number 2 solid wire. You can get both un-plated and plated copper wire in places like Home depot and Lowe's.
Your cable entrance to the building (House) is where you install your coax cable surge protection. All these surge protectors on each coax cable all get tied to the ground system you installed. The tower should have a ring around it with the ground rods spaced twice their length and all connected together. Do not connect the copper wire directly to any of the tower galvanized surfaces directly. It will cause the zinc to leach out of the galvanization and cause rusting over time. Use a bronze connector designed for this purpose. Then run the ground wire to the house with ground rods spaced twice their length going to the house. Connect your coax surge protectors to this wire. Then continue the ground wire over to the electrical meter ground rod and connect it to the ground rod.
Keep the ground wire going from your point of entry to the house for the coax cable surge protectors and the wire run to the electrical meter ground at least 3 feet away from your house foundation. Do not make any sharp bends in your ground wire runs. Use at least a 6 to 12 inch radius bend.
Hope this makes understanding a grounding system a little simpler. It may sound like a bunch of work and will incur expense for the wire and ground rods. There will be people on here that probably won't agree with what I have said. But this is what is contained in the NEC and the R56 grounding documents. The goal is to have a grounding system that is low resistance and low impedance. You might get low resistance with a single ground rod, but the low impedance comes from the multiple ground rods.
Hope this might be a little clearer now in what the goal is and how to get there.
Jim
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If someone does everything you say in below, will you guarantee they will survive a direct hit? Will you reimburse them for any equipment that is damaged from a direct hit? If so, sign me up and I'll do everything you say. If not then the advise is worth whatever your guarantee is.
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I don't want to be disrespectful Jim, but what direct, real life experience do you have with lightning?
I mean, how many times have you actually survey'd a 'crime scene' after a strike ?, or for that matter, been present when a strike(s) are actually occuring ?
I have.
This whole subject was discussed, at considerable length back in January of this year, in --
Forums, Amateur Radio, Amateur Radio Antennas, "grounding rooftop discone" (January 2019)
..... which included my account of a "Night on Bald Mountain" (Modest Mussorgsky **) scenario, which was one of my Mothers of all Lightning 'events.'
____________________________________________________________________
There is no way you can play nice with this stuff. 8 foot ground rods, #10 aluminium "grounds wires"- etc. will not do a flipping thing against a ga-zillion volt charge two miles long that just singled you out.
One of my favorite 'crime scenes' was one of our remote mountain stations. It had incurred when the wrath of the gods one summer visited us by streaking down a low, squat microwave tower, one built to withstand the next geologic epic.
The miscreant enter'd the cinderblock building via a God-knows-what pathway, -coursed across the room to the common 'floating ground' junction plate, a 3/4" thick 8x12" slab of solid copper, before it exited the building.
Sounds like everything did its jobs, huh ?
Not exactly-- in its whimsical way it must have decided the slight bend in its 3 inch (!) wide, thickly woven copper strap that leads out to the myriad of the ground matrix which encircles the building--- was just a too reactance- irksome a path to take.
So it blasted a 12 inch hole, thru the cinderblock wall, flashed over to a huge propane tank (used to run a auxillary generator during power line downs)- stripped it of half its paint -down to its shiny steel,- fused all the mounting bolts to its concrete pad--- and went on its merry way into the earth.
Another tale-
An old hard rock miner near my Colorado home loves to tell me stories of his earlier mining days.
One that sticks saliently in mind, is the time at bolt of lightning hit the headframe of their shaft. It traveled down 1300 vertical feet of open shaft, coursed along another several hundred feet of drifts, to single out and knock the bejeezus out of his pardner, who was standing right next to him -- no other damages--
______________________________________________________
Address the secondary spikes, Guys-- read the literature and become knowledgeable- but then get on with your hobby
Lauri
** Night on Bald Mountain | work by Mussorgsky
I mean, how many times have you actually survey'd a 'crime scene' after a strike ?, or for that matter, been present when a strike(s) are actually occuring ?
I have.
This whole subject was discussed, at considerable length back in January of this year, in --
Forums, Amateur Radio, Amateur Radio Antennas, "grounding rooftop discone" (January 2019)
..... which included my account of a "Night on Bald Mountain" (Modest Mussorgsky **) scenario, which was one of my Mothers of all Lightning 'events.'
____________________________________________________________________
There is no way you can play nice with this stuff. 8 foot ground rods, #10 aluminium "grounds wires"- etc. will not do a flipping thing against a ga-zillion volt charge two miles long that just singled you out.
One of my favorite 'crime scenes' was one of our remote mountain stations. It had incurred when the wrath of the gods one summer visited us by streaking down a low, squat microwave tower, one built to withstand the next geologic epic.
The miscreant enter'd the cinderblock building via a God-knows-what pathway, -coursed across the room to the common 'floating ground' junction plate, a 3/4" thick 8x12" slab of solid copper, before it exited the building.
Sounds like everything did its jobs, huh ?
Not exactly-- in its whimsical way it must have decided the slight bend in its 3 inch (!) wide, thickly woven copper strap that leads out to the myriad of the ground matrix which encircles the building--- was just a too reactance- irksome a path to take.
So it blasted a 12 inch hole, thru the cinderblock wall, flashed over to a huge propane tank (used to run a auxillary generator during power line downs)- stripped it of half its paint -down to its shiny steel,- fused all the mounting bolts to its concrete pad--- and went on its merry way into the earth.
Another tale-
An old hard rock miner near my Colorado home loves to tell me stories of his earlier mining days.
One that sticks saliently in mind, is the time at bolt of lightning hit the headframe of their shaft. It traveled down 1300 vertical feet of open shaft, coursed along another several hundred feet of drifts, to single out and knock the bejeezus out of his pardner, who was standing right next to him -- no other damages--
______________________________________________________
Address the secondary spikes, Guys-- read the literature and become knowledgeable- but then get on with your hobby
Lauri
** Night on Bald Mountain | work by Mussorgsky
I'm not asking anyone for guarantees. I'm asking for information.
I don't want to be disrespectful Jim, but what direct, real life experience do you have with lightning?
I mean, how many times have you actually survey'd a 'crime scene' after a strike ?, or for that matter, been present when a strike(s) are actually occuring ?
I have.
This whole subject was discussed, at considerable length back in January of this year, in --
Forums, Amateur Radio, Amateur Radio Antennas, "grounding rooftop discone" (January 2019)
..... which included my account of a "Night on Bald Mountain" (Modest Mussorgsky **) scenario, which was one of my Mothers of all Lightning 'events.'
____________________________________________________________________
There is no way you can play nice with this stuff. 8 foot ground rods, #10 aluminium "grounds wires"- etc. will not do a flipping thing against a ga-zillion volt charge two miles long that just singled you out.
One of my favorite 'crime scenes' was one of our remote mountain stations. It had incurred when the wrath of the gods one summer visited us by streaking down a low, squat microwave tower, one built to withstand the next geologic epic.
The miscreant enter'd the cinderblock building via a God-knows-what pathway, -coursed across the room to the common 'floating ground' junction plate, a 3/4" thick 8x12" slab of solid copper, before it exited the building.
Sounds like everything did its jobs, huh ?
Not exactly-- in its whimsical way it must have decided the slight bend in its 3 inch (!) wide, thickly woven copper strap that leads out to the myriad of the ground matrix which encircles the building--- was just a too reactance- irksome a path to take.
So it blasted a 12 inch hole, thru the cinderblock wall, flashed over to a huge propane tank (used to run a auxillary generator during power line downs)- stripped it of half its paint -down to its shiny steel,- fused all the mounting bolts to its concrete pad--- and went on its merry way into the earth.
Another tale-
An old hard rock miner near my Colorado home loves to tell me stories of his earlier mining days.
One that sticks saliently in mind, is the time at bolt of lightning hit the headframe of their shaft. It traveled down 1300 vertical feet of open shaft, coursed along another several hundred feet of drifts, to single out and knock the bejeezus out of his pardner, who was standing right next to him -- no other damages--
______________________________________________________
Address the secondary spikes, Guys-- read the literature and become knowledgeable- but then get on with your hobby
Lauri
** Night on Bald Mountain | work by Mussorgsky
Lauri-Coyote, if I were to draw up a picture of my intention and send it to you are you willing to give me an assessment? Seems like everyone is scared to really "say yea or nay" because of fear of getting sued by the person they are trying to help (not that I really blame anyone in this litigious society we are in).
I doubt if anyone here is qualified to give what you are looking for. We can point you to information like NEC, various industry and military publications, etc. My experience is you hire a professional to visit your site and they will make recommendations based on what they measure and find at your site. Every site will be different and what is adequate for the house and antenna down the street may not be for yours.
- Joined
- Jun 13, 2018
- Messages
- 869
PRC is right , KPO
No one here is qualified as an expert on this subject (at least as far as is evident.) And free advice is worth every penny you paid for it !
So emptor caveat !!
That said, I will be happy to give you my thoughts, provide you accept them as only advice !
Send me a Private Message
Lauri
______________________________________________________
......this may be a little off topic, but I just visited this site. Now this is serious static suppression! These are lightning 'arrestors' -- note also the 'air terminal'-- the lightning 'rod' that towers over them.
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No one here is qualified as an expert on this subject (at least as far as is evident.) And free advice is worth every penny you paid for it !
So emptor caveat !!
That said, I will be happy to give you my thoughts, provide you accept them as only advice !
Send me a Private Message
Lauri
______________________________________________________
......this may be a little off topic, but I just visited this site. Now this is serious static suppression! These are lightning 'arrestors' -- note also the 'air terminal'-- the lightning 'rod' that towers over them.
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Protecting one's home/ham antenna system against a direct strike is an exercise in futility. Do the best you can and then make certain that your insurance will handle the damages caused by a direct strike.
The best one can practically accomplish is to plan and implement protection against a nearby strike.
Our ham club's tower is 320' high, and has been up for just under 30 years. The highest object on our tower is a lightning rod. Every year we have to have the tower inspected and any defects mediated. This is required by our insurance company, but frankly it's just plain common sense preventative maintenance.
So far the lightning rod has had to be replaced three times. But the main point is that we've had ZERO equipment failures over that same time period.
The best one can practically accomplish is to plan and implement protection against a nearby strike.
Our ham club's tower is 320' high, and has been up for just under 30 years. The highest object on our tower is a lightning rod. Every year we have to have the tower inspected and any defects mediated. This is required by our insurance company, but frankly it's just plain common sense preventative maintenance.
So far the lightning rod has had to be replaced three times. But the main point is that we've had ZERO equipment failures over that same time period.
Damage is routinely averted. How often is your town without phone service for four days while they replace that switching computer? Never? In every town. Never. Because protection from direct lightning strikes is that routine. COs can suffer, on average, 100 surges with each storm. You many suffer maybe one surge in seven years - or less.
Why do munitions dumps suffer direct strikes without damage? Same solutions.
A Nebraska radio station suffered damage. So techs disconnected grounds assuming that was making damage happen. Finally, they hired professionals. What is the only thing that was fixed to terminate damage? Grounds. Not just any ground. Earth ground.
Even if a professional is hired, still, one must understand relevant concepts and principles. Since so many (especially those who promoted ESE devices) can easily promote scams. After all, if a surge occurs maybe only once in seven or 20 years, then would anyone know that a scam was installed?
What the informed learn so as to purchase an effective solution - a case study:
Electrical: Power Quality - Proper Copper Grounding Stops Lightning Damage
Even that last number is well understood. Lightning it typically 20,000 amps. So a minimal 'whole house' protector is 50,000 amps.
They even upgraded the essential earth ground for the AC transformer. Another concept that was only implied but was not specifically stated - follow through current. An effective solution must also make that not happen.
Is protection 100%? Of course not. Protection is typically 99.5 to 99.9% effective. An IEEE standard puts that into perspective.
Why is it not 100% effective? Because we are humans - the reason for mistakes.
When damage does happen, then investigation discovers incoming and outgoing paths that created damage. Sometimes that is a surprise. IOW we learn from our mistake.
Protection from direct lightning strikes has been routine all over the world. That protection is always defined by the quality of and low impedance connection to single point earth ground. (All four words have electrical significance.)
An investigation always begins with the only item that defines all protection - earth ground. Not safety ground, digital ground, virtual ground, chassis ground, a ground plane, or floating ground. Hundreds of thousands of joules only harmlessly dissipate in earth ground. Many professional sources are listed in an above previous post.
Damage from static electricity is hooey. That damage even made irrelevant by using an NE-2 neon glow lamp. It can change ten of thousands of volts into maybe 60 by simply conducting a milliamp of current.
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Again, your citing commercial telecommunications buildings that were designed and built from the ground up to survive lightning hits. I mentioned before I've been lead project engineer on various large antenna and equipment shelter projects and have had to specify all grounding for these projects, so I'm a little familiar with the subject and what it costs to build out a lightning resistant system. Residential homes are not designed to survive direct lightning hits and to apply the same level of protection to a home after it was built will cost tens of thousands of $$ at the minimum. Its just not practical for most people.
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