lightning protection zone (LPZ)
Lightning protection systems (LPC) are conceptually divided into different lightning protection zones ( LZ), which protect the outer part of the building with the lightning conductor and the grounding system and the inner part of the building with the various equipment for low voltage, telecommunications, water, heating, gas, TV antenna, etc. against damage.
There is the outer lightning protection zone with the building shield and the lightning conductor, which protects the building against electromagnetic pulses, Lightning Electromagnetic Pulse( LEMP). The outer lightning protection zone is divided into the area in which a direct lightning strike is possible, lightning protection zone 0A, and the protection area in which the object is not exposed to direct lightning strikes, but in which unattenuated electromagnetic fields occur, lightning protection zone 0B.
The building shield is connected to the inner protection zones via lightning protection equipotential bonding.
The inner lightning protection zone is composed of the coarse protection, medium protection and fine protection and prevents the dangerous overvoltages from penetrating to the equipment and systems and damaging them. The inner lightning protection zones are divided into lightning protection zone 1, where reduced electromagnetic fields can occur, and lightning protection zones 2 and 3, where the currents and electromagnetic fields to be discharged are reduced. The protection zones have their own room shields, which is connected to the building shield and the ground and acts like a Faraday cage. Lightning protection zone 3 includes the area of the terminal equipment and the local potential equalization. Equipotential bonding is installed between the individual protection zones.
An alternative lightning protection zone concept works with a central reference point, the single entry point( SEP), at which all incoming and outgoing lines of a building are connected together and grounded via the equipotential bonding rail.