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The exact distance of the down
conductors from each other can be
d a determined by calculating the sep-
aration distance s in accordance
b with IEC 62305-3 (EN 62305-3).
The calculation of the separation
c
A1 distance is described in chap -
A2 A3 ter 5.6.
Symbols Air-termination conductor Ideally, ridge conductors should
Connecting point have a span width up to about
Test joint 15 m and down conductors up to
A6 A5 A4 Earth conductor about 10 m without additional
A Down conductor
supports.
Important distances (minimum values) Span stakes must be firmly con-
a 0.6 m Air-term. conductor / ridge nected to the roof structure (raft-
b 0.4 m Air-term. conductor / roofing ers and crossbars) by means of an-
c 0.15 m Eaves / eaves support chor bolts and washers (Figures
A1 A2 A3 d 2.0 m Air-term. conductor / tree branches 5.1.5.1 to 5.1.5.3).
Figure 5.1.5.1 Air-termination system for buildings with thatched roofs Metal parts situated on the roof
surface (such as wind vanes, irriga-
tion systems, antennas, sheet met-
that they are free to move. Certain distances must also be al, conductors) must be completely located in the protected
maintained around the eaves. volume of isolated air-termination systems.
When a lightning protection system is installed on a roof at
a later date, the distances must be increased so that when If this is not possible, efficient lightning protection must be en-
re-roofing is carried out, the necessary minimum distances are sured in these cases. To this end, an isolated external lightning
maintained at any time. protection system with air-termination rods next to the struc-
For a class of LPS III, the typical distance of the down conduc- ture, air-termination conductors or air-termination networks
tors is 15 m. between masts next to the building must be installed.

Nr. BenennungDescription
N o . Art. Nr.Part No.
145 309
Clamping cap with air-term. rod 145 309
Spannkappe mit Fangstange
Wooden stake
145 241
Holzpfahl 145 241
Dachleitungsstütze 240 000
Roof conductor support
240 000
Eaves support 239 000
Traufenstütze
239 000
Abspannkloben 241 009
Guy clamp
241 009
Fangleitung (z. B. Al-Seil)
Air-term. conductor (e.g. Al cable) 840 050
840 050
Figure 5.1.5.2 Components for thatched roofs
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