59
A.5.2. New standard lightning and angle of protection
Lightning rod height and protection efficiencies were revised when IEC standards were renewed in
2003, replacing the older 1990 standard. The angle of protection decreases as the height of
protected structure gets higher. Any protection level of structure over 60 meters will not be enacted
in the protection angle because a lightning rod is ineffective for buildings over 60 meters when a
side-on lighting strike hits side of a building.
Protection
level
Protection
efficiency
Rolling sphere
method
Protection angle method (height: h)
Mesh method
(m)
Radius(m)
See below
I
0.98
20
5
II
0.95
30
10
III
0.9
45
15
IV
0.8
60
20
*: Applicable only to rolling sphere and mesh methods.
A.6. Conclusion
For some installations it is difficult to add a tall lightning rod because of area height regulations and
restrictions. It may be necessary to carefully consider all potential lightning protection solutions.
Figure A.7:
Protective range of rolling sphere method
Figure A.8:
Lightning rod angle of protection at protection
level IV(Protection efficiency 0.80)
Figure A.6: Protection angle corresponding to the class of LPS (IEC62305-3)
Summary of Contents for WR110
Page 1: ...INSTALLATION MANUAL WEATHER RADAR MODEL WR110 www furuno com...
Page 49: ...43 6 OUTLINE DRAWING 1 Antenna Unit...
Page 50: ...44 2 Junction Unit connection box...
Page 51: ...45 3 Junction Unit Wall mounted type...
Page 52: ...46 4 Data Processing Unit...
