How do lightning rods work

Lightning Rods Weather. Disclaimer Information Quality Help Glossary. Many people believe that lightning rods "attract" lightning. It is better stated to say that lightning rods provide a low-resistance path to ground that can be used to conduct the enormous electrical currents when lightning strikes occur.

If lightning strikes, the system attempts to carry the harmful electrical current away from the structure and safely to ground. The system has the ability to handle the enormous electrical current associated with the strike. If the strike contacts a material that is not a good conductor, the material will suffer massive heat damage. The lightning-rod system is an excellent conductor and thus allows the current to flow to ground without causing any heat damage. Lightning can " jump around " when it strikes.

This "jumping" is associated with the electrical potential of the strike target with respect to the earth's potential. The lightning can strike and then "seek" a path of least resistance by jumping around to nearby objects that provide a better path to ground. If the strike occurs near the lightning-rod system, the system will have a very low-resistance path and can then receive a "jump," diverting the strike current to ground before it can do any more damage. As you can see, the purpose of the lightning rod is not to attract lightning -- it merely provides a safe option for the lightning strike to choose.

He could confirm that the metal key was electrostatic charged, and he demostred that the clouds were electrically charged and that the lightning strikes were large electrostatic discharges. Franklin discovered that if the lightning strike or the electric fire as he called it, when it came out of the clouds and it found a metal conduit on his way to earth to get into, it would stay there and dissipate.

As a result of that crazy experiment, a year later in , he discovered the lightning rod called Franklin type and that kite became the most famous in history. Among some different effects that can produce lightning strikes, we can mention some as the thermal, physiological, electrodynamic, electrochemical effects, etc. Due to its importance we will emphasize the thermal and physiological ones. On the other hand, the physiological effects, they mainly affect living beings and occur due to the step and contact voltages that appear when the lightning is discharged to earth.

To combat and mitigate those effects, the regulations for protection against lightning establish safety measures for people and animals, such as those drafted in Annex D of the UNE standard. There are also international regulations that deal with the effects of lightning current on the human body and livestock IEC TR The thunderbolt also has two very characteristic associated effects, the lightning that is its luminous effect due to the high current circulation up to kA and the thunder that is the sound effect due to the expansive wave of the air that it is heated in few micro seconds to a very high temperatures.

When people ask us How does a lightning rod work? The negative cloud charge would not have been neutralized feet above the residence and would have entered the building, causing possible fire, destruction, side flashes within the building or even injury or death.

A negative charge or build-up occurs in the bottom part of the cloud closest to earth and a positive charge of energy occurs directly underneath in the ground. Separating these two opposite charges is the non-conducting dry air belt separating cloud and earth.