Internal Lightning Protection System
The function of an internal lightning protection system is to prevent dangerous sparking inside the structure.
This is achieved by establishing equipotential bonding or maintaining a separation distance between the components of the lightning protection system and other electrically conductive elements inside the structure.
Equipotential Bonding
Equipotential installation is achieved by interconnecting the LPS with
- Metal installations
- Internal systems
- External conductive parts and lines connected to the structure
Equipotential Bonding
Interconnecting means can be:
- Bonding conductors, where the electrical continuity is not provided by natural bonding
- Surge protective devices (SPDs), where direct connections with bonding conductors are not feasible
- Isolating spark gaps (ISGs), where direct connections with bonding conductors are not allowed
When lightning equipotential bonding for metal installations is considered, in the case of an isolated external LPS, lightning equipotential bonding shall be established at ground level only.
For an external LPS which not isolated, lightning equipotential bonding is shall be installed at the following locations:
- In the basement or approximately at ground level. Bonding conductors shall be connected to a bonding bar constructed and installed in such a way that it allows easy access for inspection
- The bonding bar shall be connected to the earth-termination system and more than one bonding bar can be installed, provided that they are interconnected
- Where separation distance requirements are not fulfilled