Conclusion - Furuno WR2120 Installation Manual

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 Protection
level efficiency
I 0.98
II 0.95
III 0.9
IV 0.8
*: Applicable only to rolling sphere and mesh methods.
Figure A.6: Protection angle corresponding to the class of LPS (IEC62305-3)
Lightning rod angle of protection at protection
level IV (Protection efficiency 0.80)
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.
Rolling sphere
method
Radius(m)
20
30
45
60
Figure A.8:
Protection angle method (height: h)
See below
Envelope surface
Protective range of rolling sphere method
61
Mesh method
(m)
5
10
15
20
Protection range
Protected structure
Figure A.7: