What is a Lightning Rod?
A lightning rod is a device which is used to divert electricity from lightning into the ground, where it can dissipate harmlessly, rather than damaging structures and trees or injuring animals which happen to be walking around above the ground. You may also hear a lightning rod called a lightning conductor or a Franklin rod, after the famous inventor Benjamin Franklin. Lightning rods are widely used all over the world in lightning protection systems, and they appear to be highly effective, since lightning-related fires and structural damage have been greatly reduced. Incidentally, English includes the slang term “lightning rod” for someone who seems to attract controversy. Classically, a lightning rod is made from metal, ideally a very conductive metal such as copper. When lightning strikes, it is drawn to the rod, and it follows a grounding cable into the ground. Lightning rods are supposed to attract lightning, drawing it away from vulnerable structures, and they are also mounted on
Also called “air terminals,” lightning rods are 12-inch rods connected to the ground by braided aluminum or copper wire. They’re mounted about every 20 feet onto the highest points of your roof—including on top of your rooftop air conditioning unit. If lightning strikes your house, it will hit the lightning rod, which will offer it a path of least resistance to the ground through wires that connect them to ground rods in your yard. The wires will drive the lightning bolt 10 feet into the ground, where it dissipates. You can place lighting rods on any kind of roof—flat or pitched, metal, shingle or foam. You can install them on outbuildings, barns, your garage and even on trees if you want to protect them.
