A Lightning Protection System (LPS) is a series of components designed to protect a structure from the devastating effects of a lightning strike.1 Contrary to popular belief, a lightning rod does not “attract” lightning; rather, it provides a safe, low-resistance path for the electrical current to reach the ground, preventing it from passing through flammable materials like wood or brick.2
How it Works
A lightning strike carries massive energy—up to 100 million volts and currents exceeding 150,000 Amperes. Without a protection system, this energy travels through a building’s structure, causing explosive heat (turning moisture into steam instantly), fires, and total destruction of electrical systems.3
The LPS works by intercepting the strike at the highest point, conducting it down the sides of the building, and dissipating it into the earth.4
Core Components of an LPS
An effective system is divided into external (physical structure) and internal (electrical systems) protection.5
| Component | Function |
| Air Terminals (Rods) | Small metal rods placed at high points to intercept the strike. |
| Conductors | Heavy-duty copper or aluminum cables that channel the current to the ground. |
| Grounding System | Rods or plates buried deep in the earth to safely disperse the electricity. |
| Bonding | Connecting all large metal objects (pipes, HVAC) to the LPS to prevent “side-flashing” (arcing). |
| Surge Protection | Devices (SPDs) installed on electrical panels to protect electronics from surges. |
Types of Systems
Depending on the building’s needs and local standards (like NFPA 780 or IEC 62305), different methods are used:
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Franklin Rod System: The traditional method using vertical rods at high points.6 It is the most common and time-tested approach.7
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Faraday Cage: A mesh of conductors covering the roof and walls, effectively “wrapping” the building in a protective shield.8 This is often used for high-security or industrial sites.
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Early Streamer Emission (ESE): An “active” rod designed to trigger a discharge earlier than a passive rod, theoretically covering a larger radius with fewer terminals.9
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Dissipation/Charge Transfer Systems: These aim to prevent a strike from forming by leaking the ground’s charge into the atmosphere, though their effectiveness is often debated among scientists.
Benefits of Installation
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Fire Prevention: Stops lightning from heating structural materials to the point of ignition.10
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Structural Integrity: Prevents the physical “explosion” of masonry or wood caused by the rapid expansion of moisture.11
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Electronics Safety: Shielding sensitive equipment (computers, appliances) from the electromagnetic pulse (EMP) of a nearby strike.12
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Insurance Savings: Many commercial insurers offer lower premiums for buildings with certified lightning protection.
Are you looking for information on a specific type of building, or would you like to know about the maintenance and inspection requirements for these systems?