6.1.3 Isolated lightning protection system

An isolated lightning protection system is a type of external lightning protection in which the air-termination systems and down conductors are spatially and electrically separated from the structure to be protected. Instead of conducting the lightning currents to earth via down conductors attached directly to the building, the lightning current is conducted away via free-standing or separately mounted air-termination systems, so that there is no direct contact between the lightning protection system and the building structure (Figure 6.1.3.1).