You can purchase the official PDF from:
: It provides guidance on insulator shapes, such as shed spacing, shed overhang, and "creepage factor," which are critical for performance in rain or coastal salt spray. iec 60815-2 pdf
The combination of cement dust (conductive when wet – high NSDD) and salt spray (high ESDD) pushes the site into Level d – Very Heavy . You can purchase the official PDF from: :
: Specific ratios for shed spacing, overhang, and creepage-to-clearance to prevent "bridging" during heavy rain or fog. such as shed spacing
: A more streamlined approach for evaluating ceramic and glass profile suitability. Practical Resources Revising IEC/TS 60815 Series & IEC 62217 - - INMR