Family sues lightning rod maker for damage Suit seeks $100,000 for property
damaged in July 1999 storm. By DAVID HOLDEN, Times Staff Writer
In 1995, the Diamantis family built a house on a grassy
hill off Ryland Pike. That year, they also joined the thousands of Americans
who have lightning rods installed to protect their homes from electrical surges
during severe thunderstorms. So the family felt secure when thunder boomed and
lightning flashed on June 5, 1999. But after that storm, the Diamantises found
themselves in the dark and in another group - this time, those who each year
reports their lightning-protection measures have failed.
Huntsville attorney Robert Gammons is suing the manufacturer of the lightning
rods the family used, Lightning Prevention of America Inc. The company is also
known as Heary Brothers Lightning Protection Co., Inc. of Springville, N.Y.
‘They have a very nice home on top of a hill,’ Gammons said. ‘It is in the opened
and exposed, and my clients were concerned about the considerable investment
they had made in their home.’ Gammons said he doesn't know whether the homebuilder
suggested lightning rods, but the devices were installed during construction.
Linda Joseph, a Buffalo, N.Y. attorney who represents Lightning Prevention of
America, did not return telephone calls about the lawsuit.
The lightning rods were properly installed and tested to confirm they were functioning
properly, the lawsuit said. The company guaranteed that the lightning rods would
provide protection for more then 100 years, according to the lawsuit.
But during the storm of June 1999, lightning caused extensive damages to the
structure of the house and to several electrical appliances, televisions and
computers. The Diamantises were home during the storm, but there were no injuries,
Gammons claims that Lightning Prevention of America's warranty was breached
when lightning damaged his clients' property. He is asking for damages totaling
$100,000 on behalf of Erica Jane Diamantis and family.
Benjamin Franklin invented lightning rods in the middle 1700s and was hailed
worldwide for harnessing lightning's destructive power.
Franklin's invention was simple: An iron rod was fastened to the top of a house.
Wire attached to the rod was stapled down the side of the building to the ground.
Franklin had documented through experiments that lightning followed the path
of least resistance to the ground, in this case, the path provided by the rod
The basic principle has changed very little since Franklin, said Mary Stacowsk
of the Lightning Protection Institute.
‘The device is not intended to attract lightning,’ she said. ‘It provides a
pathway for lightning to flow harmlessly into the ground.’
© 2000 The Huntsville Times
Response No. 1
Mike, The story in newspaper (Newsletter you send out) greatly distorts the
truth the way I understand it. Also, note that the plaintiff’s attorney provided
I live in Huntsville, Alabama and I am familiar with the house. I spoke to
the person who owns the company that installed the Heary Brothers system. According
to him, the owner was informed that they would need to have surge suppression
installed on the service to keep damages from his electronic and electrical
systems. A copy of the bid provided to the general contractor bears this out.
I was also told that when the owners were asked to produce the TVSS units (after
the damage), they were told that the owner was having them examined. When asked
where the TVSS units were installed, the owner was unable to provide this information.
The physical damage to the residence was on the exterior where the cable TV
from the utility pole turned down to entered the house. I was also told that
the area damaged was only a square about six inches on a side. I would guess
that at least part of the lightning came to the structure via the cable TV service
and it didn't make the turn from relatively horizontal to vertical (90 degree
Regards, Bob Doehrman, Doehrman@hiwaay.net
Mr. Doehrman, for whatever it's worth, I would like to let you know that you have been misinformed.
Top of the line surge protection was installed to all the electrical panels before the lightning incidence by Gurney Electric.
After the lightning all the surge protection units were tested and were found in good condition.
It would appear that they worked properly in clamping the surge but they did it on the way (of the surge) going out of the house. Feel free to talk to Gurney Electric.
Both Gurney Electric and Mr. Hearty, during his visit, measured the Grounding and found it within acceptable tolerance.
The TV cable coming into the house is another great myth. We never had cable service for the very simple reason that, to this date, there is no cable service available in our area.
Response No. 2
Hi Mike, I just had to respond. This is the old adage of "electricity
takes the path of lowest/least resistance". This fallacy has and will kill
many people before we get it straightened out. Current takes ALL paths of resistance
to ground. The amount of current is inversely proportional to the resistance/impendence
in the path taken. I know you work to dispel this.
Just look at Ohm's law and parallel circuits and we all know this is not true.
All the discussion we have had on EMI problems also help to make this point
The problem with lightening is that there are such high levels of voltage; many
paths with high resistance can be overcome. An additional problem is some current
paths become less resistive upon current flow becoming established until they
burn open or current stops flowing (i.e. people for one)
Brian Cox, email@example.com
Response No. 3
Thanks for the newspaper article on the family's home that was hit by lightning.
I learned from a lightning seminar that I attended last year that lightning
is unpredictable and you never know where it will strike. The seminar showed
a residential house that had multiple lightning rods. Lightning hit the lower
side of the house causing damage. This shows that even though lightning rods
were present, the lightning bypassed the rods and hit the house.
Sounds like a similar event happened to the house in the article you sent out.
I am surprised that the lightning rod company had a lightning guarantee when
there is no guarantee that lightning will strike a lightning rod instead of
I also learned from my seminar that lightning rods help prevent lightning from
striking by releasing opposite charges into the air. This helps prevent the
potential difference that causes lightning. However if the release of the opposite
charges does not work, the lightning rod attracts the lightning to strike the
This goes against what was said in the article ("The device is not intended
to attract lightning").
Michael Chow, P.E., MHChow@MAPLLC.com
Response No. 4
Mike, I hate to read stories like the one you sent me on the Diamantis family.
They were deceived and sold a bill of goods. Let me explain both of those statements
and if you have any questions please give me a call (407-380-9200 or 800-260-2259).
The Diamantis family did not purchase or have installed a structure lightning
protection system. They were sold a product that claims to prevent lightning
strikes. If you subscribe to that, I have some ocean front property to sell
you at low tide! Without getting into the "blue smoke and black magic"
of the manufactures claims let me just say the product called the "Protector"
is not UL listed nor is it recognized by the NFPA as a lightning protection
system. To my knowledge it and other similar devices are not recognized by any
body with creditability and has been the subject of one excellent paper as well
as more than a few discussions at IEEE meetings.
The function of a properly installed structure lightning protection system is
to provide a low impedance (resistance) diversionary path for the lightning
to follow to the earth ground. Structure lightning protection systems should
be only installed to NEC, UL and NFPA standards. It is important those purchasing
such a system understand the function of the system and its limitations. Lightning
protection systems only protect the structure and do not protected electrical
systems or sensitive electronic equipment from "surges". Structure
lightning protection systems DO NOT provide any protection from induced surges.
They are not surge protection system or devices and no such system is listed
by UL as surge protection. Surge protection is listed by UL under UL1449R2,
Structure lightning protection systems are ONLY designed to divert the energy
of a lightning strike via their components directly to earth ground. Depending
on the source it is common for lightning to exceed 100,000 volts and 40,000
or more amps. I have read documents that claim to have measured strikes reaching
more than 1,000,000 & 250,000 amps. Lightning travels for thousands of feet
without a conductor (other than ionized air, moisture and dust) so the energy
potential can reach catastrophic proportions.
There are basic elements that comprise a structure lightning protection system.
Each element is critical to the proper operation of the system.
Air Terminals: Often called lightning rods or points. These are the metal rods
often seen projecting into the air above a building. The air terminals can be
copper or aluminum.
Bonding: This is the process of bonding any metal (conductor) pipe(s), plumbing,
antenna, roof flashing, equipment, etc., that may be exposed to a lightning
strike any can be a conductive path for lightning energy to the lightning protection
Conductors: These are the heavy cables that connect the air terminals to the
grounding system. They will often be called main and down conductors and depending
on the system can be copper or aluminum.
Grounding: This is most often ground rods, ground mats or some other grounding
system. Low resistance grounding is CRITICAL to the operation of structure lightning
The function of a properly installed structure lightning protection system is
to provide a low impedance (resistance) diversionary path for the lightning
to follow to the earth ground.
Once installed the system should have a MINIMUM of annual maintenance before
each thunderstorm season. If the system is subjected to a strike it should be
inspected as soon as possible after the strike. Connections can become loose,
air terminals and other components can be damaged, etc. Lightning protection
systems are like any critical equipment, without maintenance they will cease
to function properly. The down side of this is not just an inconvenience; it
is a LIFE SAFETY ISSUE.
High performance surge protection devices are designed to protect electrical
and electronic systems from induced surges. When lightning strikes a structure
with a properly installed lightning protection system that energy will be diverted
to the grounding system of the structure. As the lightning protection system
must be bonded to the structure ground (NEC) there will be both a tremendous
surge on the ground as well as the induced energy entering any conductor in
the structure (electrical, phone, cable, network, plumbing, etc.) It is worthy
of note, just like a structure lighting protection
system, surge protection devices must be installed in a system approach. As
with any protection system, it must be complete and the devices must be capable
of protecting the equipment (appropriate devices). Not all products sold under
the general term "surge protector" are worthy of consideration.
As with any installation of life safety equipment or before making an investment
in a lightning protection or surge protection system, consult a professional.
Look for a company with excellent references and one that has been in these
professions a minimum of 5 years.
John West, firstname.lastname@example.org
Mike’s Comment: John West is one of the most knowledgeable on lightning
and surge protection, and I hold his comments in high regard.
Response No 5
Dear Mike, when I moved from Chicago to Boca Raton I was amazed at the amount
of lightning in the area. Now that I have moved to Central Florida, I really
see Mother Nature at her worst or best depending upon how you see it. The contractor
that built my home furnished a surge suppression system as part of his package.
I don't know if it is a "good" system or a cheap version but it has
served well enough so far.
I am very concerned about the lightning and am going to install a protection
system. I believe that these are two separate and distinct protection systems.
About two years ago I attended a seminar about "early emission lightning
preventor systems". I was very impressed by the technology presented and
very surprised by the number of facilities using the system. I knew that it
was not a UL listed system but that it was tested and listed by ETL.
I have decided to install that system at my home and was quite surprised to
see the information in your newsletter about the home in Huntsville, AL. I'm
quite surprised by some of the comments made by your readers.
The system I anticipate using requires proper surge suppression systems for
all incoming services to the building. My information from this company is that
their system directs the lightning discharge directly into the earth in a manner
they consider much more efficient than other systems.
I have a copy of the letter sent out by the Standards Council in which they
state their intention not to issue the 2000 edition of NFPA 780 and to withdraw
the 1997 edition of NFPA 780 and to terminate the Project on Lightning Protection.
They are soliciting comments on their intention and a final action will be taken
at the October 2000 meeting.
Mike Holt’s Comment:
Click here to to see the NFPA Standards Council action.
This action, if finalized, will probably have a great impact on the UL certification
of lightning protection installers since their certification is based on NFPA
780. I also understand that the test being conducted by UL and I believe Harger
and maybe others, on lightning protection systems shown in the NFPA Standard
have been terminated.
There appears to be a lot more than going on than a lawsuit over damage to
a home that everybody has an opinion on but that none of them have any substantial
Regards, Charlie Trout, Ctrout1018@aol.com
Mike’s Comment: Charlie is the Chairman of Code Making Panel 12 for
the NEC, representing the National Electrical Contractors Association (NECA).
Response to Charlie’s Comments:
I have to respectfully disagree with the statement in your newsletter by Charlie
Trout that states "This action, if finalized, will probably have a great
impact on the UL certification of lightning protection installers since their
certification is based on NFPA 780".
In fact the UL Master Label Program for Lightning Protection Systems is based
on UL96A - "Standard for Installation Requirements for Lightning Protection
Systems". Those installations that do not fully comply with UL96A can be
inspected to other standards (i.e. NFPA 780, AMCR 385-100, etc.) but only a
Letter of Findings will be issued.
Some information about the program can be found at the following UL web pages:
There is also available UL Publication #200-128C "UL and Lightning Protection"
that gives a very basic overview of the Master Label Program.
If you have any questions about the UL Master Label Program for Lightning Protection
System, I encourage you to contact Nancy Winter at the UL - Northbrook office,
847-272-8800 ext# 42135, and her email is <Nancy.Winter@us.ul.com>. Nancy
coordinates the UL Master Label Program.
I am an employee of UL and am contractually not allowed to publicly disseminate
information directly relating to UL issues, unless the main office has authorized
Regards, UL - Field Representative
Response No. 6
Dear Mike: At the request of a NECA-member lightning protection company, I
did some research into the background of this situation regarding the pending
withdrawal of NFPA 780. To summarize:
1. NFPA was developing a new standard, to be called 781, on the so-called "streaming
emission" lightning protection technology, which is somewhat different
than traditional methods relying on air terminals and ground wires running down
2. In response to a complaint from a major lightning protection manufacturer
charging that there was no scientific basis for judging the effectiveness of
the new streaming emission technology, NFPA convened a special task force to
review the scientific record.
3. This task force reviewed several hundred scientific papers and came to the
conclusion that, there was no technical basis for assuming that the new lightning
protection technology was any more effective than the old, and that according
NFPA 781 should not be issued.
4. In the course of that work, the task force also came to he conclusion that
there was no scientific basis for assuming that traditional NFPA 780 technology
was the best. Accordingly, they recommended that this standard should be withdrawn,
and the Technical Committee on Lightning Protection disbanded.
5. As I understand this issue (and I am not a lightning protection expert) no
one either in or outside of NFPA is saying that there should not be lightning
protection systems. And of course the old technology has been around since Ben
Franklin's time. But NFPA, as a research-oriented body devoted to developing
effective methods of fire protection, has come to the technical conclusion that
if no one can adequately explain what is actually the most effective method
of lightning protection, then NFPA standards should not prescribe certain way(s)
of doing it. In the absence of a clear scientific rationale, the marketplace
should decide how to perform lightning protection in the future.
The NFPA Standards Council is accepting public comments on this subject for
its meeting on October 6-7. There will be no additional public testimony heard,
and the final decision will be rendered based on the written record.
Sincerely, BROOKE STAUFFER
Director, Codes and Standards
National Electrical Contractors Association
Response No. 7
Mike, I can only go on experience and the experience of those that have used
the "prevention" systems. They do not function as advertised and the
experience of the folks in Alabama is but one case where a "prevention"
system did not function as advertised or sold. The "traditional" systems
work and have for a very long time. The data I have seen presented by independent
sources (not some manufacturer selling a product) does not support the claims
made for these devices. If you will look back some months you will find the
comments of an engineer on the non-traditional systems. I contacted him and
read his IEEE paper several times. I also ask some others I know and respect
to read his paper and make comments. None could find fault with the paper, the
facts presented or the conclusion.
I stand by my comments and look forward to someone that does not share my opinion
to present some facts (documented testing, long term studies, etc.). Customer
lists are evidence that someone is good at selling, not facts. I have an open
mind, I will always be willing to learn, can someone present some facts that
will support the claims?
I know of 4 companies selling some type of lightning prevention system. Only
two of those companies install their systems in a manner that resembles a traditional
lightning protection system. I have spoken to many of the customers of the prevention
systems and a good number of them have experience lightning strikes and have
suffered structure damage. That is my side of the facts.
There is a push on the part of the manufacturers of the "preventor"
type systems for the agencies and organizations to recognize their products.
The effort has resulted in a fresh look at the technology by both the agencies
and organizations. There have been threats of lawsuits (manufacturer Vs. any
who do not subscribe to their products), and a number of very heated discussions
at industry and professional group meetings. From the conversations I have had
with those in attendance some of these meeting got very ugly.
John West, email@example.com
Response No. 8
Mike, can you refresh my memory (and maybe some other readers) as to what an
"early emission lightning preventor system" is, and or does or is
SUPPOSED to do?
Bill Walker, BREKLAW@aol.com
Response No. 9
Dear Mike, re: lightening ATTRACTORS or STREAMING EMITTERS or what ever.
I have done inspection on a large college campus here in Pensacola. They had
standard lightening rods on buildings. Then someone sold them one of these 'emitters'.
The theory is that a charge of radioactive material in the device sends out
a stream of ions to make a path that goes up to provide a path to ground (through
conventional downleads) to the earth. The thing is real 'sexy' looking, like
a chrome cantaloupe with a chrome Frisbee around it and a little sharp prong
on top and mysterious portholes around the sides. Like a flying saucer. It is
to be installed on a 20 foot mast on top of the building and connected to one
down lead and cost something like $30,000.
This college built a new building, installed all the conduit and downleads for
a standard Faraday cage and then put up one of these. The electrical maintenance
man laughed just like I laughed when I heard the sales pitch. and saw one. "Snake
oil, pure and simple snake oil" it seemed and sure enough the building
got hit on a far corner before a few months went by. The factory people came
down, and paid for damage, and said the steps back on building and configurations
put the corner hit by lightening just outside the area of protection installed
another at no charge and left.
Now the electrical supervisor is a licensed electrical contractor qualifying
them to do maintenance work, though construction is by outside contractors.
The man is knowledgeable and organized. They were in the habit of changing lightening
rods (air terminals) every year to be resharpened, and check connections, etc.
well maintained. Every time a strike hit a building it would either take out
the local fire alarm, or the wiring interconnecting the buildings on campus,
so each had to be logged and noted and corrected. After a while, according to
the maintenance supervisor, he noticed that no more strikes in the area of the
new building. They changed some more buildings, and problems went away. They
have covered a large area (several blocks) and feel they have gotten their money's
Yes, this is anecdotal. But a recorded history of lightening strikes doing damage
to buildings weekly, to a much lower incidence of strikes has to mean SOMETHING.
The local installer is an electrical contractor he had done surge suppressors
on services for years and interconnected driven rods to satisfy cell tower cites
in our area. It sure seems strange, but it seems to work. I think they have
a residential version for something like $3,000.
I found it very interesting to follow the thread that you would reference every
so often, each side calling names and swearing that the other side didn't know
beans and no one with any real scientific evidence.
Oh well. If we don't know how to ground a light standard, why should we expect
them to know how to ground a lighting rod??
Response No. 10
At New Mexico Tech we have been studying lightning terminals for the past ten
years (with some of our support coming from the manufacturers of conventional
lightning protection systems). We have found that several commercial (so-called)
early streamer emission lightning terminals do not provide any better lightning
attachment than an inexpensive pointed metal rod, and probably provide less
protection than an inexpensive blunt rod. (Our results will soon appear in a
paper in the Journal of Applied
Our work is certainly not the definitive statement on early streamer emission
devices, but studies from UK and Australian universities show similar results.
If it is indeed true that an ESE device is no better than a sharpened rod, then
protecting an area of 100 meters in radius with a single ESE device will provide
considerably less protection than will a conventional system. There are currently
no such independent studies -- the only studies which indicate that ESE devices
work are those conducted by the manufacturers of the devices.
It would be good if independent studies were done. However the only parties
with financial interests in such studies are those who make and sell ESE devices,
and those who make and sell conventional lightning protection systems. The US
government, to the best of my knowledge, does not sponsor such research. The
National Science Foundation recently turned us down on a proposal for such studies.
I do not know of any independent academic or research organization getting
support for such work from federal sources. Thus, we are left with work done
by academic groups (whose results are tainted by the sponsorship of conventional
manufacturers) which show ESE devices do not provide more protection than conventional
air terminals, and work done by manufacturers of ESE devices (whose results
are tainted by their financial interests in the results) which show that ESE
devices are significantly better than conventional air terminals.
Bill Rison, Professor and Chairman, Electrical Engineering Department
New Mexico Institute of Mining and Technology
Socorro, New Mexico 87801
Response No. 11
Abdul M. Mousa, "The Applicability of Lightning Elimination Devices to
Substations and Power Lines", IEEE Transactions on Power Delivery, Vol.
No. 4, October 1998, pp. 1120-1127.
The above paper again confirmed that lightning couldn’t be eliminated and that
any claims otherwise are false. This paper is especially important because it
went through the peer review process twice as discussed hereafter.
First, it was examined by three reviewers in accordance with the practice of
the IEEE Power Engineering Society ("PES"), which does not accept
manuscripts unless they pass this review to establish that the manuscript is
sound and has archival value. Following this, the IEEE announced the availability
of pre-prints of the paper and invited discussions for publications with the
paper in accordance with the practice of the IEEE-PES.
Instead of a discussion, the IEEE got a threatening letter from Mr. Roy Carpenter,
the owner of the largest company, which produces those so-called lightning elimination
devices, claiming that his devices do prevent lightning, that the contrary statements
in Mousa's paper are not founded, and that he will sue the IEEE if it published
the subject paper.
The above threat forced the IEEE to conduct a second peer review of the paper
by three additional referees. This process confirmed that the paper should be
published. The IEEE offered Mr. Carpenter a chance to have his claims examined
by participating with Mousa and others in a panel presentation on this subject,
to be organized by the IEEE-PES and held as part of one of its regular Summer
or Winter Meetings. Mr. Carpenter declined that offer. The IEEE then published
Mousa's paper. This took place about 18 months ago and we have not heard of
Mr. Carpenter since then.
I would be pleased to send a copy of the above paper to interested readers who
do not have easy access to IEEE Transactions. Just send me your complete mailing
address via an e-mail note.
In closing, I have a few words for your readers to reflect on: All it took for
evil to triumph throughout most of mankind's history was that good people stood
back and did nothing. I do not think that this will change and I do not blame
the many silent others who believe the same like myself but avoid battling with
people like Roy Carpenter and R.W. Rapp.
In this world we live in it is the responsibility of the potential buyer of
such garbage lightning protection devices to protect himself by finding out
the facts before throwing away his/her money. With the subject being so technically
complex, however, I chose to join the courageous Dr. Bill Rison, the 17 scientists
of ICLP and others in discharging our moral responsibility by educating potential
users of lightning protection devices.
Being a little person with very limited means, I cannot respond to every false
claim being made. My voice and those of others like me will often be drowned
by the high pitch propaganda of the merchants who are putting caviar on their
tables from the sale of those ineffective lightning protection devices. Again,
it is the duty of the potential victim of those merchants to listen harder and
try to get our message to him or her. For in the end, neither I nor any one
like me loses anything when one more fool buys those devices.
Abdul M. Mousa
6911 Southpoint Drive (A03)
Burnaby, BC V3N 4X8
Tel.: (604) 528-2328 (work)
Fax: (604) 528-1883
Response No. 12
I am finding the discussion of your recent lightning story most interesting.
The one point that I have observed is that none of the lightning protection
standards really address the reliability and resistance of the grounding electrode
system. In NFPA 780 and the LPI 175, there is mention that low resistance is
desirable, but not really defined in terms that I can apply in the field. Perhaps
this is part of the problem with determining the effectiveness of either NFPA
780. We have been involved with many sites that have installed lightning protection
systems, yet they still experienced lightning damage. The main variable at these
sites has been the resistance and depth of the grounding electrodes. Perhaps
the real issue is not the resistance value under test conditions, but rather
will the grounding electrode system MAINTAIN low resistance during a discharge
event, thus minimizing voltage potential to the protected structure?
For example we did a job in Florida where we used deep driven ground rods (110'
to 130' deep) for the grounding electrode system. Not only does Florida have
a lot of lightning, but also it has some of the highest soil resistance of anywhere
in the USA. The local electrical contractor typically used 10' rods, however
we found that even 20' rods measured over 200 Ohms! By going deeper we were
able to get the system to below 5 Ohms. This building has no other grounding
electrode system. This facility has documented 4 direct lightning hits with
no internal damage to the building or technology systems. Our experience at
this facility and 140 other locations around the USA indicates deeper electrodes
are more effective in dissipating lightning while maintaining low resistance.
I know that there are a lot of opinions that says lightning will not conduct
deep into the earth due to frequency and impedance issues, however the results
indicate the opposite.
If you would like more information on deep earth grounding, please see a White
Paper on this at http://www.cpccorp.com/deep.htm.
Martin Conroy, Computer Power & Consulting
Response No. 13
I'm afraid I can't get overly excited by all the efforts to develop low resistance
grounds. The values measured are essentially made at dc (usually under 200 Hz).
Lightning is a short duration, double-exponential pulse, having a very fast
rise time. So, dynamic ground impedance (essentially, inductive reactance) is
the big player, and it is estimated to be at least an order of magnitude greater
than the value of grounding resistance. Consequently, horrendous transient voltages
are developed, despite low values of measured resistance.
Another case in point: As part of a lightning safety study I conducted for a
very large facility, we measured the lightning grounding system resistance (three-point,
fall-of-potential method) from the tip of each of the 108 lightning rods to
"true earth" some 700 feet away. From a dc stand point the facility
appeared "bullet proof." However, RF testing revealed that this gigantic,
reinforced concrete structure---with all of its lightning protection hardware
in place and properly installed---was Swiss cheese. Although the interior would
never experience the direct effects of a strike, enough energy would be conducted
inside to cause problems with sensitive assets.
R.T. Hasbrouck, EE, PE (Control Systems)
Response No. 14
Lightning recently struck a large oak tree 20ft. from the corner of my home.
It discharged into one of the roots of the tree, which obliviously was in contact
with my buried phone cable and TV cable. The lightning entered the home thru
the phone line and cable line. It was of sufficient strength that it burst the
grounding blocks for the phone and cable in half at the point they were attached
to the house. I suffered damaged electronic equipment throughout the home in
addition to burnt wires/connections to the phones and my hardwired smoke detector.
Several circuit breakers in the home popped but power to the home did not go
off. I had damage to numerous appliances and equipment but other equipment in
the home was not damaged. Devices such as my electric garage door openers, TV,
VCR's, Nintendo set, etc. were rendered inoperative. My question is, what causes
this damage to mostly the electronic equipment. Is this magnetic pressure? Your
articles speak of "acoustic shock waves", could this cause the above-described
damage? If a LPS (lightning rods) were installed at my home, would I still be
subject to this magnetic pressures and acoustic shock wave effects if I suffered
another lightning strike?
Thank you for any assistance you can provide.
Response No. 15
What causes damage to the electronics is always an electric current pulse generated
by induction of the strong electromagnetic field generated by the lightning
into any conductive body/object like wires, etc. Obviously in order to create
a current the circuit shall be "closed" respect to the voltage generator
(equivalent circuit). Obviously, especially on the mains service, the circuit
always find a closure and therefore a current can travel throughout a determined
path (normally the less inductive path), thus, if the value of this current
is high enough to create a damage (blow-up, fusion of wires, etc.) it does.
The solution is:
- A good and professionally designed grounding system (adequate section of
the ground wires, shortest possible ground link, etc).
- The use of dedicated SPD (surge protection devices) on any of the "entrance"
channel to the house, i.e. mains, telephone, external TV antennas, data line,
If your house is located in a relatively high-risk area, I strongly recommend
you implement the above techniques, just to avoid the next damage and consequential
risk also to the inhabitants.
The cost of this implementation, just to give you an idea, would be one tenth
or less of the damages cost you suffered.
Carlo Donati, Sittel - Rome, Italy