6.1.1 Non-isolated lightning protection system

An attached lightning protection system is a type of external lightning protection system in which its components, such as air-termination systems (e.g. air-termination rods or conductors) and down conductors, are installed in such a way that they are directly connected to the building structure. On its way to the earthing system, the lightning current can come into direct contact with electrically conductive parts of the building construction of the structure to be protected and be discharged into the earthing system through these parts. The separation distance between the parts carrying the lightning current and the metallic or electrically conductive parts of the building cannot be maintained in this case. To prevent uncontrolled flashovers, this type of construction requires careful planning of the equipotential bonding as part of the internal lightning protection system.