Protection of school

I Lightning rod protection
II Mesh cage protection
III Early streamer emission lightning protection system

I Lightning rod protection

Lightning Protection level: II as defined in NF EN 62 305-2

Description: 6m high lightning rods installed on the roof. Protection radius Rp = 12 meters for a Lightning Protection Level II. On the roof: equipotential interconnection of the lightning rods. On the walls: each lightning rod is connected to at least two down conductor fitted with a dedicated earth rod.

Installation schematic:

II Compare to mesh cage protection
III Compare to Early streamer emission lightning protection system

Block plan:

Estimated costs expressed as indices base 100:
Lightning rod protection: 500

II Mesh conductors lightning protection

Lightning Protection level: II as defined in NF EN 62 305-2

Description: 50 cm air terminal installed around the roof perimeter every 15 meters and on the elevator technical room located on the roof. Size of 10 meter roof mesh grid to be in accordance with a Lightning Protection Level II. On the walls: down conductors every 10 meters (accordance with a Lightning Protection Level II), the bottoms of which are connected to a series of dedicated earth rods.

Installation schematic:

I Lightning rod protection
III Compare to Early streamer emission lightning protection system

Block plan:

Estimated costs expressed as indices base 100:
Mesh conductors lightning protection: 700

III Early streamer emission lightning protection system

Lightning Protection Level: II as defined in NF C 17-102

Description: 5m high early streamer emission air terminal on the elevator technical room located on the roof. Protection radius Rp = 83.5 meters (Δt = 47μs minimum) for a Lightning Protection Level II. The lightning conductor is connected to two down conductors (see NF C 17-102 § 2.3.2), each fitted with a dedicated earth rod.

Installation schematic:

I Lightning rod protection
II Compare to mesh cage protection

Block plan:

Estimated costs expressed as indices base 100.
Early streamer emission lightning protection: 100

Tennis court

I Lightning rod protection system
II Meshed conductor lightning protection system
III Early streamer emission air terminal lightning protection system

I Lightning rod protection system

Lightning Protection Level: II as defined in NF EN 62 305-2

Description of the installation that would have to be implemented: 6m high lightning rods installed on the roof to protect the stands and the court. On the roof: equipotential interconnections between the lightning rods. Each lightning rod is connected to a down conductor fitted with a dedicated earth rod.

Remarks: The tennis court design is such that lightning rods are not able to provide complete protection of the structure in compliance with the standard. This solution must be rejected.

II Meshed conductor lightning protection system

Lightning Protection level: II as defined in NF EN 62 305-2

Description of the installation that would have to be implemented: 50 cm capture points installed around the roof perimeter every 15 meters. 10 meter roof mesh grid. On the walls: down conductors every 15 meters, the bottoms of which are connected to a series of dedicated earth rods.

Remarks: The tennis court design is such that a mesh cage lightning conductor is not able to provide complete protection of the structure in compliance with the standard. This solution must be rejected.

III Early streamer emission air terminal lightning protection system

Lightning Protection level: II as defined in NF C 17-102

Description: 5m high early streamer emission lightning conductors installed on the roof. Protection radius Rp =97 meters (Δt = 60μs) for level II protection. Each Early Streamer Emission Air Terminal is connected to two down conductors fitted with each a dedicated earth rod.

Installation schematic: