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B. Figures and tables

Figure 2.1.1 Downward flash (cloud-to-earth flash) . . . . . . . . . . . 15 Figure 3.3.1.3 DEHN Risk Tool, evaluation . . . . . . . . . . . . . . . . . 51
Figure 2.1.2 Discharge mechanism of a negative downward flash Figure 3.3.2.1.1 Kirchhoff’s law with nodes . . . . . . . . . . . . . . . . . 53
(cloud-to-earth flash). . . . . . . . . . . . . . . . . . . . 16 Figure 3.3.2.1.2 Kirchhoff’s law: Example of a building with a mesh on the
Figure 2.1.3 Discharge mechanism of a positive downward flash roof. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
(cloud-to-earth flash). . . . . . . . . . . . . . . . . . . . 16 Figure 3.3.2.1.3 Kirchhoff’s law: Example of a building with air-termination
Figure 2.1.4 Upward flash (earth-to-cloud flash) . . . . . . . . . . . . 16 system . . . . . . . . . . . . . . . . . . . . . . . . . . . 53
Figure 2.1.5 Discharge mechanism of a negative upward flash Figure 3.3.2.1.4 Resistors of the building . . . . . . . . . . . . . . . . . . 53
(earth-to-cloud flash). . . . . . . . . . . . . . . . . . . . 17 Figure 3.3.2.1.5 Node equation . . . . . . . . . . . . . . . . . . . . . . . 54
Figure 2.1.6 Discharge mechanism of a positive upward flash Figure 3.3.3.1 DEHN Earthing Tool, type A earth-termination system . . . 54
(earth-to-cloud flash). . . . . . . . . . . . . . . . . . . . 17 Figure 3.3.4.1 DEHN Air-Termination Tool, gable roof with PV system. . . 55
Figure 2.1.7 Possible components of a downward flash. . . . . . . . . 18 Figure 4.1 Components of a lightning protection system . . . . . . . 61
Figure 2.1.8 Possible components of an upward flash. . . . . . . . . . 18 Figure 4.2 Lightning protection system (LPS) . . . . . . . . . . . . . 61
Figure 2.2.1 Potential distribution in case of a lightning strike to
homogenous ground . . . . . . . . . . . . . . . . . . . . 19 Figure 5.1.1 Method of designing air-termination systems for high
buildings . . . . . . . . . . . . . . . . . . . . . . . . . . 63
Figure 2.2.2 Animals killed by electric shock due to step voltage . . . . 19 Figure 5.1.1.1 Starting upward leader defining the point of strike. . . . . 64
Figure 2.2.3 Potential rise of the building’s earth-termination system Figure 5.1.1.2 Model of a rolling sphere; source: Prof. Dr. A. Kern, Aachen 64
with respect to the remote earth caused by the peak
value of the lightning current. . . . . . . . . . . . . . . . 19 Figure 5.1.1.3 Schematic application of the rolling sphere method
Figure 2.2.4 Risk for electrical installations resulting from a potential at a building with very irregular surface . . . . . . . . . . 65
rise of the earth-termination system . . . . . . . . . . . . 19 Figure 5.1.1.4 New administration building: Model with rolling sphere
Figure 2.3.1 Square-wave voltage induced in loops due to the current according to class of LPS I; source: WBG Wiesinger . . . . 66
steepness Δi/Δt of the lightning current . . . . . . . . . . 20 Figure 5.1.1.5 New DAS administration building: Areas threatened by
lightning strikes for class of LPS I, top view (excerpt);
Figure 2.3.2 Sample calculation for induced square-wave voltages in source: WBG Wiesinger . . . . . . . . . . . . . . . . . . . 66
squared loops. . . . . . . . . . . . . . . . . . . . . . . . 20
Figure 5.1.1.6 Aachen Cathedral: Model with surroundings and rolling
Figure 2.4.1 Energy conversion at the point of strike due to the charge spheres of classes of LPS II and III; source: Prof. Dr. A. Kern,
of the lightning current. . . . . . . . . . . . . . . . . . . 21
Aachen . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
Figure 2.4.2 Effect of a short stroke arc on a metal surface . . . . . . . 21
Figure 5.1.1.7 Penetration depth p of the rolling sphere. . . . . . . . . . 67
Figure 2.4.3 Plates perforated by the effects of long stroke arcs . . . . 21
Figure 5.1.1.8 Air-termination system for roof-mounted structures and
Figure 2.5.1 Temperature rise and force resulting from the specific their protected volume . . . . . . . . . . . . . . . . . . . 67
energy of the lightning current . . . . . . . . . . . . . . . 22
Figure 5.1.1.9 Calculation of Δh for several air-termination rods
Figure 2.5.2 Electrodynamic force between parallel conductors. . . . . 23 according to the rolling sphere method . . . . . . . . . . 67
Figure 2.8.1 Lightning current measurements by the Austrian lightning Figure 5.1.1.10 Meshed air-termination system. . . . . . . . . . . . . . . 68
research group ALDIS and DEHN at the ORS transmission Figure 5.1.1.11 Protective angle and comparable radius of the rolling
mast on top of the Gaisberg mountain near Salzburg . . . 24
sphere . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Figure 2.8.2 Long stroke with superimposed impulse currents of an Figure 5.1.1.12 Protective angle α as a function of height h
upward flash with a total charge of approximately 405 As – depending on the class of LPS . . . . . . . . . . . . . . . 68
recorded at the Gaisberg transmission mast during a
winter thunderstorm . . . . . . . . . . . . . . . . . . . . 25 Figure 5.1.1.13 Cone-shaped protected volume . . . . . . . . . . . . . . 68
Figure 2.8.3 Negative downward flash with M-component (top) and Figure 5.1.1.14 Example of air-termination systems with protective angle α . 69
partial lightning current in a power supply line (below) – Figure 5.1.1.15 Volume protected by an air-termination conductor. . . . . 69
recorded at the Gaisberg transmission mast . . . . . . . . 25 Figure 5.1.1.16 Volume protected by an air-termination rod . . . . . . . . 69
Figure 3.2.3.1 Flash density in Germany (average from 1999 to 2011) Figure 5.1.1.17 Protection of small-sized roof-mounted structures against
according to Supplement 1 of DIN EN 62305-2 Ed. 2:2013 direct lightning strikes by means of air-termination rods. . 71
(source: Blitz-Informations-Dienst by Siemens). . . . . . . 33
Figure 3.2.3.2 Equivalent collection area A D for direct lightning strikes to Figure 5.1.1.18 Gable roof with conductor holder . . . . . . . . . . . . . 71
an isolated structure . . . . . . . . . . . . . . . . . . . . 35 Figure 5.1.1.19 Flat roof with air-termination rods and conductor holders:
Figure 3.2.3.3 Equivalent collection area A M , A L , A I for indirect lightning Protection of the domelights . . . . . . . . . . . . . . . . 71
strikes to the structure . . . . . . . . . . . . . . . . . . . 35 Figure 5.1.1.20 Isolated external lightning protection system with two
Figure 3.2.8.1 Flow diagram for determining the need of protection and separate air-termination masts according to the protective
angle method: Projection on a vertical surface . . . . . . . 71
for selecting protection measures in case of types of loss
L1 to L3. . . . . . . . . . . . . . . . . . . . . . . . . . . 46 Figure 5.1.1.21 Isolated external lightning protection system consisting
of two separate air-termination masts connected by a
Figure 3.2.9.1 Flow diagram for selecting protection measures in case of horizontal air-termination conductor: Projection on a
loss of economic value . . . . . . . . . . . . . . . . . . . 47 vertical surface via the two masts (vertical section) . . . . 72
Figure 3.3.1 Start screen of the DEHNsupport Toolbox software. . . . . 49 Figure 5.1.2.1 Air-termination system on a gable roof. . . . . . . . . . . 73
Figure 3.3.1.1 Calculation of the collection area . . . . . . . . . . . . . 50 Figure 5.1.2.2 Height of a roof-mounted structure made of non-
Figure 3.3.1.2 DEHN Risk Tool, division into zones. . . . . . . . . . . . . 51 conductive material (e.g. PVC), h ≤ 0.5 m . . . . . . . . . 73
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