XZERES Wind Skystream 3.7, Руководство пользователя

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Skystream Owner’s Manual
3-CMLT-1054 Rev O XCO 1191
Pg. 48
Determine Tower Height
Determine your tower height and select Table 1, 2, 3 or 4 corresponding to a 33, 45, 60 or 70 ft. tower
(10, 14, 18 or 21 m). Tables 1, 2, 3 and 4 are used to calculate the Lightning Protection System
Efficiencies corresponding to the tower height.
IMPORTANT: If the tower height falls in between the heights for which the tables are available
in this manual, select the table for the next higher tower height.
Determine the Flash Density (Ng)
Determine the Annual Average Ground Flash Density (per km2), Ng, in your area. This number may be
obtained from information published by National organizations, meteorological organizations and is
generally available on the internet. For example, Global Atmospherics Inc. (also known as Vaisala-GAI
Inc.), publishes lightning strike data. Be careful to obtain most recent data available, as there may be
considerable variability in data from one year to next, especially with the present climate change.
An example website is given below:
http://www.crh.noaa.gov/pub/?n=/ltg/flash_density_maps_index.php
Ng may range anywhere between 1 and 70. Select the row corresponding to the Ng in your area. For
non-integer values, the next higher integral number must be chosen.
Warning: Be careful to obtain most recent data available, as there may be considerable
variability in data from one year to next, especially with the present climate change.
Table 1 - Lightning Protection Efficiency for 33 ft (10 m) Towers
Isolated Flat Land Hill or Knoll Non-Isolated Flat Land
Ng E = Lightning protection
system efficiency
E = Lightning protection
system efficiency
E = Lightning protection
system efficiency
Nc=
1/100
Nc=
1/1000
Nc=
1/10000
Nc=
1/100
Nc=
1/1000
Nc=
1/10000
Nc=
1/100
Nc=
1/1000
Nc=
1/10000
0.01 0.001 0.0001 0.01 0.001 0.0001 0.01 0.001 0.0001
1 -1.353 0.765 0.976 -0.176 0.882 0.988 -3.705 0.529 0.953
2 -0.176 0.882 0.988 0.412 0.941 0.994 -1.353 0.765 0.976
3 0.216 0.922 0.992 0.608 0.961 0.966 -0.568 0.843 0.984
4 0.412 0.941 0.994 0.706 0.971 0.997 -0.176 0.882 0.988
5 0.529 0.953 0.995 0.765 0.976 0.998 0.059 0.906 0.991
6 0.608 0.961 0.996 0.804 0.980 0.998 0.216 0.922 0.992
7 0.664 0.966 0.997 0.832 0.983 0.998 0.328 0.933 0.993
8 0.706 0.971 0.997 0.853 0.985 0.999 0.412 0.941 0.994
9 0.739 0.974 0.997 0.869 0.987 0.999 0.477 0.948 0.995
10 0.765 0.976 0.998 0.882 0.988 0.999 0.529 0.953 0.995
11 0.786 0.979 0.998 0.893 0.989 0.999 0.572 0.957 0.996
12 0.804 0.980 0.998 0.902 0.990 0.999 0.608 0.961 0.996
13 0.819 0.982 0.998 0.910 0.991 0.999 0.638 0.964 0.216
14 0.832 0.983 0.998 0.916 0.992 0.999 0.664 0.966 0.997
15 0.843 0.984 0.998 0.922 0.992 0.999 0.686 0.969 0.997
16
0.853 0.985 0.999 0.926 0.993 0.999 0.706 0.971 0.997
17
0.862 0.986 0.999 0.931 0.993 0.999 0.723 0.972 0.997
18
0.869 0.987 0.999 0.935 0.993 0.999 0.739 0.974 0.997
19
0.876 0.988 0.999 0.938 0.994 0.999 0.752 0.975 0.998
20
0.882 0.988 0.999 0.941 0.994 0.999 0.765 0.976 0.998
30
0.922 0.992 0.999 0.961 0.996 1.000 0.843 0.984 0.998
40
0.941 0.994 0.999 0.971 0.997 1.000 0.882 0.988 0.999
50
0.953 0.995 1.000 0.976 0.998 1.000 0.906 0.991 0.999
60
0.961 0.996 1.000 0.980 0.998 1.000 0.922 0.992 0.999
70
0.966 0.967 1.000 0.983 0.998 1.000 0.933 0.993 0.999