Lightning Protection of Industrial Plants using the 3-D Rolling Sphere Method Part I - Air Terminals and Metal Masts

A rigorous methodology for the design validation of air-termination systems compliant with NFPA 780 and IEC 62305 standards using the 3-D Rolling Sphere Method approach is described. Air terminals located at the top of either structures or metal masts are defined using only their spatial tip coordinates. Quadratic equations of lateral and top rolling sphere centers are solved. Geometric modelling of Limiting Boundary Protection Surfaces using Boolean differentiation via mathematical inequalities is proposed. An example application focused on an Industrial Plant with Hazardous Areas will be covered in a following paper.