Faq

1. What is Lightning ?

Lightning is fascinating to watch but also extremely dangerous. It is an atmospheric discharge of electricity accompanied by thunder, which typically occurs during thunderstorms, and sometimes during volcanic eruptions or dust storms.

2. How destructive is a lightning strike ?

A lightning can travel at speeds of 220,000 km/h (140,000 mph), and can reach temperatures approaching 30,000 °C (54,000 °F), hot enough to fuse silica sand into glass channels known as fulgurites which are normally hollow and can extend some distance into the ground. There are some 16 million lightning storms in the world every year. It can damage roofs, explode brick and concrete and ignite fires. In addition to personal physical damage, it can wreak havoc with computers, electronic equipment and appliances. The number of homes struck by lightning every year is increasing and losses exceed cores of rupees annually.

3. What is the difference between a thundershower and a thunderstorm ?

Technically, there is none. In general, the term "thundershower" tends to denote a fairly weak storm with light to moderate rainfall and low levels of lightning activity. However, there are no defined parameters that distinguish between a thundershower and a thunderstorm. In fact, in order to avoid confusion, we in the National Weather Service do not use the term "thundershower". If a shower is strong enough to produce lightning, even just one single bolt, it's called a thunderstorm.

4. How Thunderstorms Develop ?

All thunderstorms go through stages of growth, development, electrification, and dissipation. Thunderstorms often begin to develop early in the day when the sun heats the air near the ground and pockets of warmer air start to rise in the atmosphere. When these pockets of air reach a certain level in the atmosphere, cumulus clouds start to form. Continued heating causes these clouds to grow vertically into the atmosphere. These "towering cumulus" clouds may be one of the first signs of a developing thunderstorm. The final stage of development occurs as the top of the cloud becomes anvil-shaped.

As a thunderstorm cloud grows, precipitation forms within the cloud. A well-developed thunderstorm cloud contains mostly small ice crystals in the upper levels of the cloud, a mixture of small ice crystals and small hail in the middle levels of the cloud, and a mixture of rain and melting hail in the lower levels of the cloud.

Air movements and collisions between the various types of precipitation in the middle of the cloud cause the precipitation particles to become charged. The lighter ice crystals become positively charged and are carried upward into the upper part of the storm by rising air. The heavier hail becomes negatively charged and is either suspended by the rising air or falls toward the lower part of the storm. These collisions and air movements cause the top of the thunderstorm cloud to become positively charged and the middle and lower part of the storm to become negatively charged.

In addition, a small positive charge develops near the bottom of the thunderstorm cloud. The negative charge in the middle of thunderstorm cloud causes the ground underneath to become positively charged, and the positively charged anvil causes the ground under the anvil to become negatively charged. How

5. How far can lightning strike ?

Almost all lightning will occur within 10 miles of its parent thunderstorm, but it can strike much farther than that. Lightning detection equipment has confirmed bolts striking almost 50 miles away, but these are very rare. Understanding the dangers of lightning is important so that you can get to a safe place when thunderstorms threaten. If you hear thunder even a distant rumble or a crackling aloft you are already in danger of becoming a lightning victim.

The sound of thunder travels about a mile every 5 seconds. If you count the seconds between the flash of lightning and the crack of thunder and divided by 5, you get the number of miles away from you (10 seconds is 2 miles).

6. How to protect us from Lightning ?

There is no safe place outside when thunderstorms are in the area. If you hear thunder, you are likely within striking distance of the storm. Just remember, When Thunder Roars, Go Indoors! Too many people wait far too long to get to a safe place when thunderstorms approach. Unfortunately, these delayed actions lead to many of the lightning deaths and injuries.

The best way to protect you from lightning is to avoid the threat. You simply don’t want to be caught outside in a storm. Have a lightning safety plan, and cancel or postpone activities early if thunderstorms are expected. Monitor weather conditions and get to a safe place before the weather becomes threatening. Substantial buildings and hard-topped vehicles are safe options. Rain shelters, small sheds, and open vehicles are not safe.

A safe shelter from lightning is either a substantial building or a enclosed metal vehicle. A safe building is one that is fully enclosed with a roof, walls and floor, and has plumbing or wiring. Examples include a home, school, church, hotel, office building or shopping center. Once inside, stay away from showers, sinks, bath tubs, and electronic equipment such as stoves, radios, corded telephones and computers. A safe vehicle is any fully enclosed metaltopped vehicle such as a hard-topped car, minivan, bus, truck, etc. While inside a safe vehicle, do not use electronic devices such as radio communications during a thunderstorm. If you drive into a thunderstorm, slow down and use extra caution. If possible, pull off the road into a safe area. Do not leave the vehicle during a thunderstorm.

7. Who invented Lightning Protection system ?

The earliest literature available that proposes protection from lightning starts in 1752 with Benjamin Franklin. Franklin’s original idea was to use a sharp point to draw charges from the cloud to discharge it and thus prevent lightning. Early experiments by Franklin in electrostatics had him arrive at this conclusion. By placing objects with different geometries (sharp and blunt) near a charged object, Franklin found that differing amounts of charge were drawn from the original charged object. (Later researchers would come to understand that electrostatic lines of force concentrate at sharp points, theoretically verifying his electrostatic experiments.) He consequently published the first instruction for protection from lightning.

8. Is lightning protection proven science ?

Yes. Lightning protection has been saving homes and other structures for well over 100 years. The basic science of lightning protection goes back to the days of Ben Franklin. The latest codes and regulations NFC 17-102 780 incorporate over 200 years of scientific study and provide the only way to reliably and consistently protect your building from lightning damage.

9. Does lightning travel vice versa ?

An entire lightning strike employs both upward and downward moving forces. However, the return stroke of a lightning bolt travels from the ground into the cloud and accounts for more that 99% of the luminosity of a lightning strike. What we see as lightning does indeed travel from the ground into the cloud.

10. What is lightning protection ?

A lightning protection system protects your home, office, commercial building, or other structure from lightning damage. Lightning damage can include complete or partial loss of a building and its contents due to fire and structural damage. Lightning damage can also include damage to computers, electronics, appliances, electric fences, satellite dishes, telephone systems, hot tubs, and more.

11. What is the need of lightning protection ?

Good lightning protection is solid, straightforward science. A lightning protection system performs a simple but crucial task. Lightning contains millions of volts of electricity. When lightning strikes your building, your lightning protection system provides a specified, highlyefficient path on which the millions of volts of electricity can travel safely to the ground. On a building without lightning protection, those same millions of volts of electricity still have to get to the ground. Lightning will use your electrical wiring, your telephone or cable wiring, structural elements of your building, or anything else it can find as a “path to ground”. None of these building elements is designed to safely carry this amount of electricity. The result is a build-up of resistance, which leads to fire and explosive damage to your building. Your lightning protection system gives the lightning exactly what it needs – an easy and efficient path to ground. The result is usually no damage to your building. In fact, if you are not in the building when lightning strikes, you may not even know the building was struck.

12. How a Lightning Protection System Works ?

Lightning is the visible discharge of static electricity within a cloud, between clouds, or between tile earth and a cloud. Scientists still do not fully understand what causes lightning, but most experts believe that different kinds of ice interact in a cloud. Updrafts in the clouds separate charges so that positive charges moves end up at the top of the cloud while negative flow to the bottom. When the negative charge moves down, a "pilot leader" forms. 'This leader rushes toward the earth in 150-foot discrete steps, ionizing a path in the air. 'The final breakdown generally occurs to a high object the major part of the lightning discharge current is then carried in the return stroke which flows along the ionized path. A lighting protection system provides a means by which this discharge may enter or leave earth without passing through and damaging non-conducting parts of a structure, such as those made of wood, brick, and tile of concrete. A lightning protection system does not prevent lightning from striking; it provides a means for controlling it and preventing damage by providing a low resistance path for the discharge of lightning energy.

13. How ESE Based Lightning Air Terminal Works ?

The air terminal is a device for lightning protection with a spherical metal part fixed to the top. This sphere is insulated from the rod by a ring made from a material with very high electrical insulation properties. When a storm comes, the external electrode (sphere) charges under the influence of the electric field until the potential reaches a critical value from which a spark appears between the exterior electrode and the tip of the central electrode. The tip enables plasma to be created close by the tip. The plasma, in association with the intense electric field created close by the tip, constitutes the first stage of development of an upward leader. The spark produced at the top of the air terminal will initiate the advance of the discharge, engendering an upward leader moving in the direction of the downward leader.

14. Does it require any power supply or battery back-up to function ?

No, it does not require any power supply or power back-up. STAR ESE terminals do not work with any power back-up. It is very clearly declared/mentioned in their technical brochure. It works just based on the change in the atmosphere charges. The moment the charges in the atmosphere exceeds the threshold level (i.e. spark over voltage of the ESE terminal - the potential different between the blades and base unit), the charges are emitted outside in the cloud thus attracting the lightning.

15. What is the protection radius and height of the mast ?

We suggest only maximum height of 5 meter from the roof height and level 3 protection of 107 meters radius. Mast height is mentioned from 2 to 20 meters. Increase in protection radius is very good from 2 to 5 meters. After 5 meters, there is no big gain in protection radius just by increasing the mast height. This is decide as per the NF C 17 102 formula (i.e. as per National French Commission standard).

16. What is Conventional Lightning Protection System ?

The conventional lightning protection system forms a kind of metal grid on top and around the building. Here the copper/GI strips form a kind of grid with each other and at every 3 to 5 meters a sharp metal rod of about 1 foot is placed. Then after some distance interval the down conductors (strip) is placed and then to earth pits. By doing this the maintenance of all this put together becomes a costly & wastage of time. In some conditions, however the active lightning system is the only possible method to protect from direct lightning strokes. Due to the arguments mentioned above, it is recommend using the lightning protection system whenever the conventional solution is inconvenient or when the former is more preferable to the latter as in the case of the efficient protection of architect.

17. What are my chances of being struck by lightning ?

This is a seemingly simple question, but there is no single answer that fits everyone. Good factors are the Geographical location and annual climatology.

18. What should I do if I'm caught out in the open during a thunderstorm and no shelter is nearby ?

There are no safe places outdoors during a lightning storm. Avoid open fields, the top of a hill or a ridge top. Keep your self away from tall, isolated trees or other tall objects. If you are in a forest, stay near a lower stand of trees. If you are camping in an open area, set up camp in a valley, ravine or other low area. Stay away from water, wet items such as ropes and metal objects, such as fences and poles. Water and metal are excellent conductors of electricity. The current from a lightning flash will easily travel for long distances.

19. Can lightning strike me while I'm indoors ?

YES! If a bolt strikes your house or a nearby power line, it can travel into your house through the plumbing or the electric wiring! If you are using any electrical appliances or plumbing fixtures (including telephones and computers), and a storm is overhead, you are putting yourself at risk. About 4-5% of people struck by lightning are struck while talking on a corded telephone.

20. Can I use my cell phone or cordless phone during a storm ?

Yes. These are safe to use because there is no direct path between you and the lightning. Avoid using a corded telephone unless it's an emergency.

21. Do people still use lightning rods ?

Yes. In fact, more lightning protection systems are installed now than ever before. Today’s lightning protection systems are inconspicuous. Since buildings today are equipped with many sensitive electronic systems, planners tend to include lightning protection systems not only to protect the structure but also to help protect the electronic systems and to keep the buildings up and running.

22. Lightning never strikes the same place twice, right ?

Wrong. In fact, a building or area that has been hit can indicate that the area is a “hot zone” for lightning strikes. Some buildings get hit so often that we install a “counter” as part of the lightning protection system to keep track of the lightning strikes. The Empire State Building(USA) gets struck by lightning, on average, over 100 times a year, yet suffers no damage due to its lightning protection system.

23. Our electrician says our home is grounded. Does that protect us from lightning damage ?

No. The electrical ground installed by your electrician is there to protect the internal workings of the electrical system in your building. It is not at all designed to protect you from lightning damage.

24. What are surge protection devices (SPD)? Why is it part of a lightning protection system ?

SPD’s are installed where utilities such as electrical service, telephone, and cable or satellite enter your building. When a nearby or distant utility pole or transfer station gets struck by lightning, damaging surges can come down the wires into your building. SPD stop these surges before they start electrical fires and before they cause damage to your computers, electronics, and appliances. So, SPD means your lightning protection system is effective even when your building does not suffer a direct lightning strike.

25. When is the best time to install lightning protection on building ?

Lightning protection can be installed at any time. It is better and advisable when new construction is taking place.

26. How long will my lightning protection system last ?

Your lightning protection system is designed to last for the life of your building. If you make structural changes or additions, you should have your system checked and updated if needed.

27. Is lightning protection as important today as it used to be?

Your lightning protection system is designed to last for the life of your building. If you make structural changes or additions, you should have your system checked and updated if needed.

28. If a lightning is struck and if we touch a victim, we’ll be electrocuted ?

The human body does not store electricity. It is perfectly safe to touch a lightning victim to give them first aid. This is the most chilling of lightning Myths. Imagine if someone died because people fail to give first aid (CPR).

29. If there is a steel frame in a building is it already safe ?

The structural steel of a building does conduct lightning, but you need a lightning protection system to provide the necessary interconnections to make sure that the lightning is able to pass harmlessly through the building. Without the lightning protection system, when a building is struck the lightning attempts to find a path to ground. If there are not enough interconnections providing a continuous path for the lightning to follow, there will be arcing or side-flashing. The lightning will also travel on other mechanical systems in a building such as the electrical or HVAC systems. The lightning current jumping from object to object within a building is dangerous and has been known to cause fires, explosions, etc.

30. What types of buildings need lightning protection ?

Any structure is a good candidate for lightning protection. All buildings are subject to lightning damage. A structures use and contents are as much a consideration as location and construction when determining lightning risk. It is commonplace for lightning protection systems to be installed on schools, hospitals, health care facilities, airports, shopping centers, office buildings, manufacturing facilities, etc.

31. How much does lightning protection cost ?

Cost varies greatly depending on the location of the structure, its size, its construction, the complexity of the roof-line and the ground conditions. Costs are lower when the system is designed and installed during construction. Retrofitting a system, is very common, but tends to be slightly more expensive. In comparison with other building systems, such as security or plumbing, the lightning protection is usually less costly.