What is Lightning?
Lightning is an electrical discharge between charged particles in a cloud and the ground.
The air normally insulates electric charges, but under high voltage (around 3 million V/m), it breaks down and allows current to flow.
Lightning strikes occur when electrical charges build up in a cloud beyond the resistance of air.
What is a Lightning Rod?
A lightning rod is a pointed metal object installed on top of buildings to attract lightning strikes.
Lightning strikes the rod because pointy objects create stronger electric fields, ionizing the air and providing a path for current to flow.
The rod is designed to be the first object lightning strikes, as it offers the least resistance for the electrical discharge.
Where Does the Current in a Lightning Rod Go?
The lightning rod is connected to a wire that leads to the ground, where the electric charge dissipates safely.
The Earth has a virtually infinite ability to absorb electric charge, acting as a "bucket" for the current.
In grid-connected systems, lightning arresters direct the high current safely away from sensitive electronics.
Can Lightning Evade a Lightning Rod?
Lightning can evade a lightning rod if:
The rod is poorly designed, installed, or maintained.
It's positioned too close to other structures or at the wrong height or angle.
It fails due to corrosion or improper grounding.
A strike is more attracted to nearby tall objects or ascends from the ground to meet the descending strike.
Dangers of a Lightning Rod
A flawed installation (like a bent wire) can cause current to short circuit.
In the 1960s, the Ufer grounding system (concrete-encased electrodes) was developed for better conductivity.
Standards from the International Electrotechnical Commission guide the design and safety limits of lightning rods to prevent failure and risk.
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