A lightning/surge arrester is a device that protects structures from electrical damage by intercepting lightning surges and diverting them to the ground. Lightning arresters are connected directly to the ground via low resistance cables, although they are generally mounted on high buildings or other structures in order to attract electricity. They can be used on land and in sea, with the latter version using the water to discharge electricity. Lightning arresters are available in many different forms and are used in a variety of applications.

How to Design Lightning Arresters
In a basic lightning arrester design, numerous grounding rods are driven into the soil. A strong copper coil is then wrapped around and welded to each of these rods from top to bottom. As lightning is attracted to the top of the lightning arrester, the electricity is directed down the rods through the copper coils and dispersed into the soil. While not all lightning arresters are the same (they can be designed in several completely different ways), this is the most basic form of lightning protection. Another type of lightning arrester consists of a gas filled tube that conducts a current and disperses it through metal contacts at the bottom.

Applications
Lightning arresters can be used for many purposes. They are used on tall buildings to prevent lightning from causing physical damage to infrastructure. Lightning arresters are also used on power lines to protect the fragile cables from lightning, electromagnetic forces, downed power line poles, and other natural phenomena. Additionally, lightning arresters are used on power outlets to protect electronic devices from electrical surges.

Advantages
Lightning arresters have several advantages. They can be mounted onto nearly any structure and used to protect virtually any electronic device. Indoor lightning arresters are generally compact and have specific indicator lights that display whether an electronic device connected to the lightning arrester is protected from electrical surges and spikes. Lightning arresters are rather inexpensive and can handle high current levels.