What is a Lightning Protection System?

A lightning rod  or lightning conductor  is a metal rod mounted on a structure and intended to protect the structure from a lightning strike. If lightning hits the structure, it will preferentially strike the rod and be conducted to ground through a wire, instead of passing through the structure, where it could start a fire or cause electrocution. Lightning rods are also called finials, air terminals, or strike termination devices.

In a lightning protection system, a lightning rod is a single component of the system. The lightning rod requires a connection to earth to perform its protective function. Lightning rods come in many different forms, including hollow, solid, pointed, rounded, flat strips, or even bristle brush-like. The main attribute common to all lightning rods is that they are all made of conductive materials, such as copper and aluminum. Copper and its alloys are the most common materials used in lightning protection.

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.

Typically, the only things visible on a lightning protection system are the air terminals, 10″-12″ copper rods, on the chimney and roof ridges. If the system is to be installed on an existing building, every effort is made to conceal the copper cable