The Santísima Trinidad del Paraná Jesuit mission is a set of mission towns founded in the seventeenth century by the Catholic religious order of the Jesuits among the Guarani Indians. It is the best preserved and most extensive mission in Paraguay, and so,was declared as World Heritage Site by UNESCO in 1993 being an important tourist attraction in the country.
For designing the lightning protection system, first the risk was evaluated according to the international standard IEC 62305-2, using the application developed by Aplicaciones Tecnológicas, S.A., CD-RISK software. According to the results, a Lightning Protection Level III together with co-ordinated lightning protection is needed for a correct protection.
Since the installation is to be protected in an open area, the proposed protection system was formed by 4 DAT CONTROLER® PLUS 60 Early Streamer Emission air terminals accomplishing the UNE 21186 standards, which coverage is sufficient for the area to be protected. Existing concrete posts were employed for placing the 4 air terminals so as to be higher than the objects to be protected.
DAT CONTROLER® PLUS air terminals have the highest guarantees of good performance, as N mark of AENOR endorses. They meet the requirements of the latest editions of lightning protection normative and go even beyond these standards with a comprehensive quality control, severer current withstanding tests and a certification of working under rain.
As the risk assessment already indicates, the installation of the air terminals together with their down-conductors and earthing, avoids direct lightning strikes to the structure but not secondary effects to service lines that reach the electric and electronic equipment. Therefore, a co-ordinated surge protection is needed.
After studying the power supply installation, the proposed solution was type 1 for the main board using ATSHOCK surge protectors, which withstand 50 kA impulse current per pole. The boards of the control cabin will be protected with ATCOVER surge protectors, which let a residual voltage lower than 900 V.