The internal system prevents dangerous sparking inside the structure. Lightning current traveling down the external system creates massive electromagnetic fields, which can induce dangerous voltages in nearby metal objects and electrical lines. Internal protection relies on:
Down-conductors should be installed straight and vertical to offer the shortest path to the ground. Earth-Termination System iec 62305-3 pdf
National standardization bodies (such as in the UK, DIN in Germany, or ANSI in the USA). The internal system prevents dangerous sparking inside the
Yes. The official IEC documents are published in English and French. Select your language during purchase. DIN in Germany