4.3 Earth-termination system

The main task of the earthing system of a lightning protection system is to safely and controllably dissipate the lightning current into the ground after a strike in order to protect people, buildings and technical equipment from the effects of intense electrical energy.
In the context of IEC 62305-3, the earthing system performs the following tasks:

• Discharge of lightning currents from the external lightning protection system into the ground
• Potential control to prevent dangerous voltage differences in and around the building
• Prevention of flashovers through low-resistance connection to the surroundings
• Integration into the lightning equipotential bonding for internal protective measures