Page 7 - Planning_Lightning_Protection

Environmen-
Urban environment: C = 0.01 tal factor Urban environment (buildings < 20.0 m) : C = 0.1
e e
Suburban environment (e.g. in the outskirts): C = 0.5 C Rural environment (e.g. small village) : C =1
e e
e

Each risk component consists of different factors: Loss L X
In addition to the frequency of dangerous events and the
R = N x P x L probabilities of damage, possible loss must also be cal-
X X X X
culated. Losses are differentiated according to the risks
These factors are defined as follows: considered in the risk analysis and thus according to the risk
components. The following losses can be determined:
N = Number of dangerous events per annum
X
P = Probability of damage to a structure L Loss of human life:
X
L = Consequent loss 1
X • Touch and step voltage
• Fire
Frequency of dangerous events N X
A variety of parameters are required to calculate the fre- • Overvoltage / LEMP
quency of dangerous events N , for example:
X
• Lightning ground flash density N L Loss of services to the public:
2
G
• Collection area A • Fire
D
• Location factor C • Overvoltage / LEMP
D
• Environmental factor C
E
L Loss of cultural heritage:
3
Probability of damage P X • Fire
The probability P describes the building and installation
X
properties of a structure. These properties can reduce or L Loss of economic value:
4
increase the risk. Particularly the risk of fire, which defines • Touch and step voltage
the specific fire load of a structure, plays an important role • Fire
when performing a risk analysis.
• Overvoltage / LEMP

LEMP = Lightning Electromagnetic Pulse
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