**Lightning took out my TV and Receiver...Questions!**

[westom]

Your saying a 18awg wire carrying 60,000 amps of current will not result in wire damage...

I quoted engineers, scientists, and industry standards. I did not say carrying 60,000 amps. I said conduct something less than 60,000 amps. Meaning 20,000 amps (a typical direct lightning strike) is routinely earthed without damage.

And now for the 'asterisk'. We were taught these principles in high school physics. Neither current (amps) nor power (watts) cause damage. Energy (joules) causes damage. Energy is defined by three parameters: volts, current and "TIME". Another intentionally misrepresented the front page title article from EE Times by ignoring a statement that defines 'time'. For extremely long times, that 18 AWG (ten amp) wire conducts something less than 83 amps. For lightning, that wire conducts something less than 60,000 amps without damage.

Lightning has great power but less energy. Or as Colin Bayliss wrote in his book "Transmission & Distribution Electrical Engineering":

Although lightning strikes have impressive voltage and current values, the energy content of the discharge is relatively low and most of the damage to power plant is caused by 'power follow-through current'.

What is often a high energy source - the follow-through current? AC electricity provided by the utility.

If lightning is properly earthed BEFORE entering a building, then a higher energy source does not do significant damage. Earth lightning to avert damage BEFORE it enters a building. So that protection already inside every appliance is not overwhelmed. Earthing (not a protector) defines protection. Earthing usually involves 2, 4, or 6 millimeter (12, 6 or 2 AWG) wire. Significantly oversized so that physical and environmental threats do not harm or break that wire. And made as short as practicable so that protection is effective.

A 'whole house' protector to connect 50,000 amps to earth without damage typically uses a 2 millimeter wire. Why does that meet all industry safety standards? Why can the manufacturer make claims with that 50,000 number? Underlying concepts were originally taught in high school physics. EE Times (and other professionals) defined those concepts with hard numbers.

Still many will deny this by ignoring concepts from high school physics, ignoring those engineering numbers, and making disparaging remarks. Many would 'kill the messenger' rather than admit to being easily manipulated by fables and feelings. EE Times made statements with hard and accurate numbers. Many who deny never post numbers. Somehow they just know. Numbers are how you separate myth purveyors from the informed. Or what Tom Friedman calls "navigation".

 

[Chu Gai]

Westom seems to have managed to garner quite a negative reaction. What I don't understand is what specifically is the objection to implementing a whole house surge protection scheme? Is it because it's not 100% effective? If so, by that way of thinking neither are infant car seats, seat belts, condoms, etc.

 

[Ampdog]

Chu Gai,

There cannot be any objection to a whole house surge protection scheme - at least not by me. What I feel is being mixed up here is "surge protection' vs "direct strike protection". Although linked, the one has little to do with the other as far as practices for avoing damage done by each respectively is concerned.

To repeat: Surge protection addresses a mostly short high voltage spike entering homes via the mains system. It is, by way of speaking, a closed loop thing. Such spikes can vary considerably in their voltage value or energy content; the latter can mostly be handled by good surge protectors. Energy from a direct strike to a building may or may not enter such a circuit; that is viewed separately.

There is little protection against a direct strike, again depending on the energy content. One is obviously not worried about low energy strikes, (Consider the building insurance 'avoidance' measure of requiring the protective inverted cone of no field strength 'generated' by a high enough mast to minimise the possibility of sufficient field strength build-up to hopefully avoid a direct strike - not so much to absorb the energy of such when it occurs, as some think.)

Westom,

Just for the record. I belonged to a research division of the RSA Council for Scientific and Industrial Research, tasked to examine lightning damage, which cost the RSA Electricity Supply Commission millions every year. Research funds alone went into the many hundreds of thousands per annum. As said before, Pretoria is the centre with the third most regular lightning strike count in the world in summer, thus our ability to have contributed significantly to global information on lightning physics and damage.

As such, I may be excused for saying that we know a thing or two about lightning. To be kind, your knowledge on the subject, or at least your statements, are so mixed up that it is difficult to comment on them. You would gain by first mastering more electricity basics before trying to analise matters concerning voltage, current, power and energy regarding the above terrain. Yes, time is involved. Yes, energy is joules. It also has to do with R.I(sq). We can talk again after you have seen the damage done to sturdy power distribution sub-stations. You can then try to apply your logic to how a 1" thick copper conductor several feet long got "evaporated" by a lightning strike. That requires a little more than high school physics.

As said, just for the record .....

 

[westom]

To be kind, your knowledge on the subject, or at least your statements, are so mixed up that it is difficult to comment on them. You would gain by first mastering more electricity basics before trying to analise matters concerning voltage, current, power and energy regarding the above terrain.

I did this stuff even multiple decades ago. But somehow I don't know this stuff?

An engineer would say ‘which’ concepts are misunderstood. Useless are empty accusations. If you really know this stuff, then post facts - not accusations. State specifically which concepts are misunderstood. Or ask questions that include numbers. Or provide those corrected concepts. Science is based in numbers. Junk science is based in subjective statements; as you posted.

Again to be clear, if electricity basics need be mastered, then define each specifically. Not doing so makes you appear to be just another uninformed plaintiff.

If a problem exists with the science, then fill this board with knowledge. We know that radio stations, telephone exchanges, munitions dumps, airports, ships, high voltage transmission lines, trees, rocket launch facilities, and buildings are routinely struck without damage. Damage means humans learn of and correct their mistakes. But many here foolishly know that nothing protects from direct strikes when example after example for over 100 years say otherwise.

Of course, protection is not 100%. The IEEE defines protection with numbers.

Lightning cannot be prevented; it can only be intercepted or diverted to a path which will, if well designed and constructed, not result in damage. Even this means is not positive, providing only 99.5-99.9% protection. ...
Still, a 99.5% protection level will reduce the incidence of direct strokes from one stroke per 30 years ... to one stroke per 6000 years ... Protection at 99.5% is the practical choice.

Which is your belief? Do you agree with the IEEE? Or with many who ‘know’ protection from direct strikes is impossible?


OP would have damage due to ineffective earthing and protectors. Therefore he all but invited a surge current to go hunting for earth destructively via his appliances. And can easily avert future damage by asking how to upgrade both earthing and protectors.


A final point. A classic scam is known as Early Streamer Emission (ESE). A concept totally rejected by many professional organizations including the NFPA. Even condemned in numerous IEEE papers. Discharging air does not provide protection. Lightning rods do not do that. But the scam lives on.

Why did the NFPA in 2000 reject ESE (submitted by Heary Bros)? NFPA said no responsible study justified ESE. Or more accurately,

… there was no basis for the Council to issue a standard for ESE lightning protection systems, and that given the lack of validation of the primary claims made for the ESE technology, renewed standards development activities for ESE systems was not appropriate.

ESE protection is unjustified. Facts that say why are also provided.

If concepts need correction, then do not post accusations. Instead post corrections.

 

[Rickster71]

Westom seems to have managed to garner quite a negative reaction. What I don't understand is what specifically is the objection to implementing a whole house surge protection scheme? Is it because it's not 100% effective? If so, by that way of thinking neither are infant car seats, seat belts, condoms, etc.

You'd have to go back a few years and look at his past posts / ramblings.

In the beginning he only preached Grounding.
When it was explained to him (ad nauseum) that surges and lightening strikes were two totally different animals, and that a surge could be generated from inside the home, on a phase that had nothing to do with Ground.
Along with the fact that Power Companies used large scale surge protection. He very slowly added whole house protection to his endless ramblings.

If you want someone that 'cuts & pastes'... has about 40% knowledge on the subject and has never worked a day in the field....he's your man.
When his mom finds out he's on her computer again, she's gonna be pissed.

 

[Chu Gai]

You'd have to go back a few years and look at his past posts / ramblings.

In the beginning he only preached Grounding.
When it was explained to him (ad nauseum) that surges and lightening strikes were two totally different animals, and that a surge could be generated from inside the home, on a phase that had nothing to do with Ground.
Along with the fact that Power Companies used large scale surge protection. He very slowly added whole house protection to his endless ramblings.

If you want someone that 'cuts & pastes'... has about 40% knowledge on the subject and has never worked a day in the field....he's your man.
When his mom finds out he's on her computer again, she's gonna be pissed.

My understanding of Westom differs somewhat from yours. Somewhat. What I know of him significantly predates his signing up for an AH membership and harkens back to USENET which is now known as Google Groups for you young un's.

Westom has managed to accumulate a significant quantity of information regarding protecting personal residences when it comes to surges particularly as it relates to those induced by lightning. It comes from a variety of sources including but not limited to information from companies who specialize in lightning protection such as PolyPhaser as well as studies done by various scientific organizations. I would imagine that most of it is referenced somehow in sundry files. It's my opinion, as it seems to be yours, that he does cut and paste in order to try and make points to support his philosophy (approach) to mitigating the deleterious effects of surges.

As a result there are times, perhaps often, that his posts do not directly address questions and seem to go off in tangents. Further, his posting style typically has an abrasive tone to it which alienates people and as a consequence they may look to dismiss the content of his posts. Diplomacy and the ability to bring people around to one's POV are not his strong suits. As to what he knows about electricity, I can't put a percentage on it. Just because one is an EE does not mean they are skilled in this particlar area of lIghtning mitigation. Other sciences are often brought to bear such as physics.

The points that Westom consistently made, which as I've said significantly predate his joining up here are as follows.

1) The NEC is concerned about human safety not transistor safety. To go beyond human safety grounding may need to be improved and he has spoken about how that can be done.
2) He advocates for addressing surges originating outside of one's domicile before they can enter the home. To that end, he is a proponent of whole house protection which means that all incoming lines need to be protected by a device which is also connected to a good earth ground in the proper manner. (Where he and I differ, I think, is that we also benefit by having point of use devices strategically placed within the home. A reason which was pointed out by JNeutron over at AVS has to do that there can be coupling of a home's wiring with external electrical events due to induction.)
3) He has sought to properly define surges as high energy events which are high voltage, high current occurrences of incredibly short duration such as microseconds. What people call surges is often at odds with such a definition. I've seen people and even companies improperly call overvoltages, swells, spikes, noise, etc. surges.
4) He states that relying on just a surge protector within the home is not only not a cost effective approach but that it is not as effective as a device located at the breaker box which has a much shorter path to earth ground.

I'm sure there are other things too but in general I haven't found what Westom has brought to the table egregiously incorrect.

 

[Rickster71]

1) The NEC is concerned about human safety not transistor safety. To go beyond human safety grounding may need to be improved and he has spoken about how that can be done.

I don't have any knowledge of Westom other than at this site. I also don't know of his credentials, if any.
Your first point about the NEC and Westom's tying that into lighting protection and grounding.
It's not, nor has it been part of the NEC.
NFPA 780 deals specifically with lightning protection.
My contention is...if he knew his stuff, he'd know that.

2) He advocates for addressing surges originating outside of one's domicile before they can enter the home.

My issue with him saying this: All surges, spikes, don't necessarily originate from outside the home.
He rarely, if ever, differentiates between lightening strikes and surges, or spikes.

3) He has sought to properly define surges as high energy events which are high voltage, high current occurrences of incredibly short duration such as microseconds. What people call surges is often at odds with such a definition. I've seen people and even companies improperly call overvoltages, swells, spikes, noise, etc. surges.
4) He states that relying on just a surge protector within the home is not only not a cost effective approach but that it is not as effective as a device located at the breaker box which has a much shorter path to earth ground.

He's wrong on point 4). At some undetermined point the MOV's in any protector will reach the end of their useful life.
With that in mind, layering protection is a good solution.

I'm sure there are other things too but in general I haven't found what Westom has brought to the table egregiously incorrect.

See points above.
Other issues: The history of his posts here have absolutely changed over the agonizing years.
He originally stated the contention, Surge Protection "Did not work"
When I pointed out to him that the Power Companies used large scale surge protection. He slowly incorporated whole house protection into his ramblings.

He doesn't appear to have any interest in audio or home theater.
He instead, trolls the Surge and Lightening threads.

Frankly, when it comes to lightening protection, I don't know of much that will really work... Other than a Halo system and good insurance
With the former being out of reach for the home owner.

 

[Chu Gai]

Hard to beat well thought out house insurance but what do you mean by lightning protection?

BTW, I skimmed through the NFPA standard (http://www.uscg.mil/Petaluma/TPF/ET_SMS/Manuals/NFPA_780.pdf) and with the exception of installing things like air terminals, westom's suggestions don't seem to be at odds. It may well be that even if he wasn't familiar with it, the information he has presented may well have been culled from it from various sources.

 

[Rickster71]

............. the information he has presented may well have been culled from it from various sources.

Exactly.
I been reading up a little on the Web MD site.
I'm going to go troll the New England Journal of Medicine

 

[westom]

NFPA 780 deals specifically with lightning protection.
My contention is...if he knew his stuff, he'd know that.

NFPA 780 is only for lightning protection for human safety. Nothing in the NFPA discusses protection of transistors. You should have known that before posting attacks and denials.

Since I know this stuff, professionals are routinely cited. Another says what you should have known. From Standler's book:

This situation could be resolved by the use of mandatory standards ... At this time this book was written (1988), the author saw no hope of such standards being adopted in the United States for overvoltages on the mains.

Nothing in the electrical code (as Standler notes) defines protection of appliances. Code defines protection of human life. You would know that had you asked to learn rather than post caustic accusations.

My issue with him saying this: All surges, spikes, don't necessarily originate from outside the home. He rarely, if ever, differentiates between lightening strikes and surges, or spikes.

For one very simple obvious reason. Your accusation again demonstrates your knowledge is devoid of perspective - the numbers. Anything inside a house that creates destructive surges 1) is destroying itself. 2) Surge protection must be on the surge creating appliance - not on all other appliances. 3) How often are your appliances destroying dimmer switches, GFCIs, and digital clocks? Hourly? Daily? Why not? Because a surge invented by ignorance (by forgetting to include numbers) is only "noise". Noise made irrelevant by protection already inside every appliance. You would know about that existing protection IF you first learned some numbers.

Protection that even makes lightning irrelevant also makes ‘assumed’ interior surges irrelevant.

He's wrong on point 4). At some undetermined point the MOV's in any protector will reach the end of their useful life.

Correct. And had you first learned numbers, then you know when that end of life occurs. But again, only a few learn this stuff by reading MOV manufacturer datasheets. And actually making direct lightning strikes irrelevant. One MOV manufacturer says how to test MOVs:

The change of Vb shall be measured after the impulse listed below is applied 10,000 times continuously with the interval of ten seconds at room temperature.

When does that MOV fail? When its threshold voltage Vb changes by 10%. No physical indication of failure exists. Even the protector light does not report normal MOV failure. Any protector that fails catastrophically even violates MOV manufacturer specs. And then we have the additional risk of fire.

How many surges before it fails? 10,000 when a protector is fully sized? Why do grossly undersized protectors fail catastrophically (dangerously) on a first or second surge? Take a $3 power strip. Add some ten cent protector parts. Sell a grossly undersized protector for $25 or $100 to the naive. When it fails, the naive will automatically recommend it. Then the naive recite a myth that nothing can protect from direct lightning strikes.

Responsible clams are tempered by numbers from professionals and from manufacturers with integrity. That even say why direct lightning strikes do not damage superior (and less expensive) protectors. Now that you post reasons for your denials, well, each is obviously incorrect. After all, how many times a day are you replacing digital clocks destroyed by the vacuum cleaner, refrigerator, air conditioner, furnace, or washing machine? Never. You knew that and still posted the lie that sells undersized and ineffective protectors.

Cheapshots inspire the naive. But then I am not posting for the ignorant. Even though the ignorant prove their superiority by posting insults. Posted was protection for the fewer consumers who choose to be informed. Who spend tens and 100 times less money to have protection even from direct lightning strikes. With spec numbers that say why they remain functional. How do you deny those facts? Cheapshots.

Consumers who learn reality earth effective protectors that even remain functional after direct lightning strikes. Responsible manufacturers including Polyphaser, General Electric, Intermatic, ABB, Siemens, Leviton, Ditek, Cutler-Hammer, Keison, and Square D - to name but a few. The naive foolishly recommend a Belkin on hearsay and wild speculation. By ignoring spec numbers that even say a Belkin is only near zero protection.

Posts have not changed. You simply get angry rather than learn well proven science. Well understood concepts from over 100 years have always been in these posts. You just never bothered to read them with sufficient care. A protector is only as effective as its earth ground. Reality does not change because you did not like it. Or because advertising taught you something different.

You did not even know the NFPA is about protecting human life. NFPA is not about protecting appliances. You should have known that before even posting denials.

This is damning. An informed poster know NFPA is about human safety. Hearsay tells the naive something completely different.

The OP can have superior protection if he ignores so many personal attacks. And asks about how to better earth surges and protectors. Unfortunately, the most naive have been permitted to fill this discussion with disparaging and inaccurate personal attacks. So many important details and recommendations still remain unposted. Honesty is not possible in a thread contaminated by cheapshots and other personal attacks.

You did not even know what NFPA does.

 

[Ampdog]

Westom (after long weekend),

OK. Let me start with an apology; I did not mean to offend you. If your perception was that, I apologise. But what arrived at me seems to differ from reality - at least here in RSA. And as said, we were on the forefront of the lightning phenomenon research, if only because of the regularity of the occurence; ideal circumstances for research!

Yes, there are many 'down-strikes' not resulting in damage. Also because many of them do have a short time duration. But regarding the OP's question, we are concerned with those that do lead to damage - certainly protection of people as you say, but also protection of expensive equipment. The main thrust of our research concerned damage to electricity supply lines running over vast uninhabited areas; not much possibility of human danger there but damage management into the many millions. Still.

Also I must respectfully disagree that the lack of quoting of figures necessarily disqualifies one from commenting. I could have cited reams of tables - but all this was more than two decades ago; it is hidden somewhere in the CSIR archives. I simply do not have a photographic memory, nor did one memorise what was available on hard copy!

The time duration of such damaging strokes which did occur here and were worthy of protection measures, were of the order of milliseconds; occasionally featuring several discharges along the same path. You only had to see damage caused by such as said earlier to realise that enough energy was dissipated to burn through most protective measures once it started. I see preventative measures as I think you do, as pro-active stuff; an effort to avoid the buiding up of sufficient charge to cause a down-strike of damaging energy. Once such a strike does occur, it is too late. The energy contained will simply burn its way through whatever is in its way. (Do note therefore that I am talking of the damaging strikes, not the 'safe' ones.) In that sense I have no quibble with IEEE information; we are perhaps only talking of two different things.

Before deviating too far from the original topic, let me just mention something else. Somewhere I read that such down-strikes as referred to above occurs - er - only <1% of the total instances? If that was said, it is actually an impossible figure to establish - how can one possibly count all lightning strikes during any specific storm so as to come to a percentage? You would know that there are always lightning somewhere on the planet. As I type several storms would have come and gone somewhere, and when you read this some time later, many others will be active somewhere. As said, one is not concerned with whatever fraction of the total (although we had a gallant try at that), one is concerned with those which will do damage, which will burn its path open and threaten life and property. If it is the IEEE's contention that such occur once every x years only .... it is not I who disagree with the IEEE; it is they who disagree with our findings. Perhaps two different countries, blah blah blah - whatever. The huge regular cost of such damage was not a thumb-suck by our Electricity Supply Commission - it sadly was and is stark reality.

And as for the 60 000 amps discharged in such a short time that a say 18 gauge wire will deal with it - sorry, not per the examples I mentioned above (and furthermore sorry, I am not going to take time to calculate a figure here simply to satisfy you. Respectfully, this is not a treatise for a degree, I am simply trying to qualitatively contribute to the OP's question. Which I think I have done by now.)

 

[westom]

But regarding the OP's question, we are concerned with those that do lead to damage - certainly protection of people as you say, but also protection of expensive equipment. The main thrust of our research concerned damage to electricity supply lines running over vast uninhabited areas; not much possibility of human danger there but damage management into the many millions. ...

The time duration of such damaging strokes which did occur here and were worthy of protection measures, were of the order of milliseconds; ...

Before deviating too far from the original topic, let me just mention something else. Somewhere I read that such down-strikes as referred to above occurs - er - only <1% of the total instances?

Rare (1%) surges (ie 100,000 amps and larger) are why a minimal 'whole house' protector is 50,000 amps. A 1979 Martzloff IEEE paper describes a typical 100,000 amps strike. 40,000 amps goes to earth via the 'primary' protection system (installed by the utility). Another 40,000 amps approaches the consumer's appliances. And some 20,000 amps typically goes elsewhere. Because an 18 AWG (1 mm) wire is electrically (but barely) sufficient for that current, then standard is to earth that current with a 6 AWG (4 mm) wire. Meaning the wire typically used to earth direct lightning strikes has a current rating about 15 times larger.

Protection equipment is typically rated using the industry standard 8/20 microsecond or 10/1000 microsecond waveforms. The actual construction of a lightning bolt takes milliseconds. But it destructive current discharge is microseconds. Protection is about the actual current - in microseconds. Significant voltage exists only when something foolishly tries to stop or block that current.

Above assumes no follow-through current. For example, if the 'primary' protection layer is compromised (a picture demonstrates one example of how at Florida Power & Light and BellSouth ), then a truly high energy source can connect far more than hundreds of thousands of joules into the structure. That energy is not from lightning. Energy is from sources with higher energy potentials.

This event apparently happened to a California radio station. Since a 33,000 volt transformer was not properly earthed, then lightning created a plasma connection from 33,000 volts distribution to low voltage building power. Lightning was the low energy transient that created an electric short circuit. Then 33,000 volts from the utility literally exploded a transmitter building. Only tiny pieces of the transformer were discovered. Solution was to earth that surge BEFORE it could create a plasma short circuit. The primary protection layer was defective. Once a fault (short circuit) was created inside the transformer, nothing was going to avert resulting high energy damage.

Energy content of lightning is relatively low. Earthing direct strikes without damage is routine IF proper earthing and good electrical connections to earth (wire and protectors) are implemented. Protectors do not do protection. Protectors only do what wire does better. Protection is defined by what absorbs even hundreds of thousands of joules. So that nobody knows a surge existed.

Protection from direct strikes is routine. A lightning strike that would not harm a tree is still potentially destructive to household appliances; if not properly connected to earth outside a building. How frequent? Worldwide, such surges may occur once every seven years. That number for each neighborhood can vary. Even geology affects the actual number.

So homeowners should routinely earth a 50,000 amp 'whole house protector - the 'secondary' protection layer. And inspect their 'primary' protection layer. If a protector is damaged anytime in the next 20 years, then a replacement protector should be 100,000 amps or larger. If interior appliances are damaged, then the first item inspected for a human created fault is the earthing system and connections to it.

That is a generic answer for the OP and anyone else. To provide the OP with a better answer requires details including geology, neighborhood history exceeding a decade, and all incoming electrical conductors (including buried pipes).

We know direct lightning strikes without damage are routine. Technology is so well understood that damage is considered a human mistake. Should damage occur, find and fix that mistake. Damage is often due to oversight. Lightning is a good instructor. It will find that oversight. The resulting damage means a human should correct his mistake; the reason for that damage.

Some numbers (ie 100,000 amps) describe the 1% of earthed lightning strikes that most people never witness. Far more common lightning strikes, that hit trees without damage and yet easily damage appliances, are typically 20,000 amps. Even 2000 amps strikes exist. All require proper earthing so that nobody even knew such surges existed.

The 'art' of protection is a single point earth ground.