Rolling Sphere Method Calculator 〈480p 2027〉
A smaller sphere (Level I) is more "touchy" and will probe into every crevice, providing the highest level of protection. A larger sphere (Level IV) offers less stringent protection, suitable for ordinary structures. The Core Equation To determine if a point at height ( H ) is protected by a lightning mast of height ( h ) (with ( h > H )), the horizontal distance ( d ) from the mast to the point must satisfy:
But manual RSM calculations are tedious and error-prone. Enter the —a digital tool that transforms complex 3D geometry into actionable protection zones. This article explains the physics behind the method and how to leverage a calculator for real-world designs. The Physics: Why a Sphere? The Rolling Sphere Method is based on a simple premise: Imagine a sphere of a fixed radius, ( r ), rolling over the terrain and over the structure in question. Where the sphere touches the ground or a lightning protection system (LPS), it represents a point a lightning leader could attach. Any volume that the sphere cannot touch (because it is shielded by a mast, air terminal, or the ground itself) is considered protected. rolling sphere method calculator
| Protection Level | Peak Current (kA) | Rolling Sphere Radius (r) | | :--- | :--- | :--- | | Level I (Highest) | 3 kA | 20 m (66 ft) | | Level II | 5 kA | 30 m (98 ft) | | Level III | 10 kA | 45 m (148 ft) | | Level IV (Lowest) | 16 kA | 60 m (197 ft) | A smaller sphere (Level I) is more "touchy"