What is a Lightning Protection System?
A lightning protection system is a passive means of preventing property damage from the effects of a lightning strike. It works by providing the electric charge produced by the clouds a path of least resistance to the ground. There are four main parts of a properly installed lightning protection system: copper air terminals, copper cable, copper clad ground rods, surge suppressors. The air terminals and cable are typically copper, but sometimes they can (or must) be aluminum. All of the air terminals are connected via the cable which has a minimum of two ground rods buried 10 feet below grade. This system is then grounded to both the water pipes and existing ground of the circuit box. The surge suppressor can be connected to the breaker box to cover the entire electric system or they can be placed at individual appliances or electronics. When most people hear the term lightning rod, they picture large ornate rods with heavy cable draped on the roof and down the sides of old homes (see
In the context of lightning protection, the word “system” can be reasonably interpreted using the definition “a combination of interacting or interdependent components, assembled to carry out one or more functions”. The interacting components are the various parts such as air terminals, main conductors, connectors, and grounding terminals, that are assembled, that is, installed and connected, to perform the function of minimizing the damaging effects of lightning. There are several potentially damaging effects, such as heating, fire ignition, high voltage transients, sparks, electric and magnetic field interactions, hazardous voltage formation, etc., and an integrated protection system requires a sufficient number and distribution of all parts in order to accomplish its desired function of minimizing the probability of any damage.
