Lightning arresters are installed on many different pieces of equipment such as power poles and towers, power transformers, circuit breakers, bus structures, and steel superstructures in substations. A substation is a high-voltage electric facility containing equipment to regulate and distribute electrical energy. While some substations are small with little more than a transformer and associated switches, other substations are large and complex. Lighting Arresters are protective devices for limiting surge voltages due to lightning strikes or equipment faults or other events, to prevent damage to equipment and disruption of service. Also called surge arresters.