A Lightning Protection System (LPS) is design to protect a structure from damage due to lightning strikes. Despite the many types of installation, we can clearly identify that they are two lightning protection philosophies which are based on principles diametrically opposite :
Tesla’s Method – To avoid lightning formation ( Deionization )
Franklin’ s Method – To attract lightning strike on lightning rod ( Ionization )
Origin of lightning suppresor
Nikola TESLA is an inventor and engineer from 19th century, it is notoriously known for its leading role in the development and adoption of alternating current for the transmission and distribution of electricity.
He also created the Tesla coil which is used to produce high-voltage at low-current, high frequency alternating current , and he created the world’s first wireless remote control . Tesla was recognize as “The master of lightning”.
LPS design by Tesla
In 1916, the brilliant inventor Nikola TESLA point out that Franklin’s lightning rod greatly increased the risk of lightning strike and decided to create “the lightning protector” which is founded on principles diametrically opposite by using a large round shape to secures a very low density and preserves insulating qualities of the ambient medium.
The Tesla’s lightning protector was design to regulate the electric environment which prevent lightning formation.
"Nikola Tesla, Expert on High Frequency Currents, such as lightning discharges, has recently patented the new "Rounded" form of lightning rod, which he states is superior to the time-honored "Pointed" rods so familiar to all of us. Also, Dr Tesla has good reasons for this radical departure in lightning rod design."
Deionization step by step :
The lightning suppressor CMCE have been designed following Tesla’s principles in order to eliminate potential difference between ambiant atmosphere and protected structure.
By absorbing and draining excess charges to the grounding system, the CMCE avoids the excessive concentration of opposing electrostatic charges which prevents the streamer emission and eliminate lightning formation in the protected area.
Step 1 :
Charges from the grounding system (positives) are distributed into the device from several earth electrodes. Charges from opposite sign (negatives) are collected from other free electrodes.
Step 2 :
As charges of opposite sign attract each other, the system absorbs charges that appears in the surrounding electromagnetic field. The potential difference between 2 electrodes generates an electric voltage (V).
Step 3 :
The electric voltage (V) generated by the ordely movement of charges between the electrodes creates a controlled flow of leakage current (I) in harmless milliamperes.
The pointed lightning rod conductor also call lightning attractor or Franklin rod was created by Benjamin FRANKLIN in 1752 as part of his groundbreaking exploration of electricity.Franklin with the assistance of his son William proposed and experiment with conductive iron rods and wire to attract lightning and conduct current to the ground.
The experiment’s purpose was to demonstrate that lightning and electricity were the result of the same electrical phenomenon.
Franklin's design to attract lightning :
Conventional LPS are using Franklin’s rods to attract lightning strike on preferential impact point, the lightning current flow through copper down conductors to the earth in order to dissipate lightning current (rolling sphere method, angle calculation method).
In 1836 Michael Faraday invented the “Faraday cage” also name “mesh method” which is form by a continuous covering of conductive material.
Many improvement have been done to increase ionization phenomenon especially with active lightning rods as ESE which are designed to increase streamer emission and to capture lightning strike on a larger radius.
Ionization step by step :
Step 1 :
When the atmospheric conditions changes, the lightning rod collect opposite charges and brings them to its tip.
Step 2 :
The accumulation of charges will generate streamer (leader) in order to collect lightning on its tip.
Step 3 :
The lightning current will flow through copper down conductors to join the grounding system to dissipate the lightning current into the earth.