Lightning protection earthing systems. These earthing systems are designed to dissipate the lightning energy into the ground mass. The earthing system should minimize the ground voltage potential rise and therefore lessen the risk of injury to personal and damage to equipment.
An earthing system is a below-grade conductor network designed to allow electrical energy (from an above-grade network) to transition from the conductor network into the surrounding native soil (earth). Lightning and surge protection devices work by routing voltage surges and spikes away from the electrical components they are protecting and dispersing it to a ground plane (making use of an earthing system), such as the earth or a copper pipe inside of a building.
The key difference between earthing and grounding is that the term “Earthing” means that the circuit is physically connected to the ground which is Zero Volt Potential to the Ground (Earth). Whereas in “Grounding” the circuit is not physically connected to ground, but its potential is zero with respect to other points.
An improper grounding connection can cause disaster sometimes as the lightening may find another route like plumbing to reach to the ground, which will produce the same effect as that of a lightning striking any building and can result in fire. Even simple grounding is not advisable for such a system.
Lightning protection systems intercept this voltage, providing a safe path for lightning current into the ground. They do not decrease the likelihood your home may be struck, but provide a direct path to ground, preventing damage to your home from fire, explosion, and electrical surges that can result from lightning strikes.
It is rare for a house to be devoid of electrically conductive paths to ground, but they do exist – such as camping/fishing cabins. In that case, all bets are off on how the lightning will choose to reach the ground.