Rolling Sphere Lightning Rod

[timm33333]

Is there some way to perform IEC-62305 rolling sphere lightning rod analysis without the use of software? There must be some method that people used when there were no computers.

 

[7anoter4]

IEC 62305-3 ch.5.2.2 Table 2 indicates the rolling sphere radius according to LPS[LPL] class.
IEC 62305-1 Table 6 the minimum peak current and the rolling sphere radius according to LPL class.
The Rrolling=10*I^0.65 m [I[kA].
You may check the rolling spheres contain no equipment [or other element] on a drawing [or sketch].

 

[abrahamJP]

For Rolling sphere method to be valid Rolling sphere must be tangent to earth/lower roof and
in contact with higher portion of roof.

For protection Level-1 ,radius of protection is 20mtrs.

If I have a building of height 90mtrs,how Rolling sphere can cover this.I mean,on vertical height??

 

[timm33333]

For protection level I, the building of heights up to 20m do not need LPS (lightning protection system) on vertical side. For taller buildings, the top 20% of vertical side of building needs LPS. So for 90m tall building, top 18m on the vertical side shall need LPS.