TBS. Interception system The task of lightning protection systems is to intercept and safely arrest the lightning strike. Lightning protection
systems consist of lightning rods, cables and sometimes loop systems with defined heights and loop sizes.
The basis for installing lightning protection systems is DIN VDE 0185 Parts 1 to 4. OBO offers an entire range of
tested interception and connection systems that afford your building clever lightning protection.
174 TBS Interception and arrester systems
Principles
from page 178
Products
from page 186
175
TBS
System overview
from page 176 Interception and arrester systems
System overview
176 TBS
Conducter materia
Lightning rod/
stand
from P. 188
Test Boxes
from P. 220 177
TBS
Insulated
interception devices from P. 191
l
from P. 186
Roof conducter holder
from P. 192 h
The interception system is part of the external light-
ning protection, which is responsible for intercepting
lightning strikes. In principle, an interception system is
to be installed so that the corners and edges of the
building are protected.
Question 1:
What is the building type?
The protection method depends on the building type
in question. The table opposite shows which method
is correct in each case.
Question 2:
What is the lightning protection class of the
building?
Before a lightning protection system is planned, a
lightning protection class for the property to be protected
must be defined. According to the applicable standard,
a detailed knowledge of the property and the resultant
risk factors are required to establish the lightning pro-
tection class. If Table 3 in VDS Directive 2010 is used,
this detailed knowledge and/or risk factors are not
required to classify the building. For example, lightning
protection class III is recommended for a public
administration building.
Step 1:
Determine the height of the building
Determine the ridge height of the building (see dia-
gram: h). This height is the starting point for planning
the entire lightning protection system. The ridge con-
ductor is arranged on the ridge and thus forms the
backbone for the interception system. In our ex-
ample, the building is 9 m high.
h
10
20
30
40
50
60
70
80
0
0
10
20
30
40
50
60 h (m)
I
II
III
IV
°
= Lightning protection angle
h = height of ridge
I / II / III / IV = lightning protection classes
°
Step 2:
Determine the protective angle
The height of the building (in this case: 9 m) is
entered onto the horizontal axis on the diagram
(see graphic opposite). Then proceed vertically until
you meet the curve for your lightning protection class
(in this case III). You can now read the protective angle
from the vertical axis
. In our example, the angle
is 62°.
Transfer the protective angle to the building. All build-
ing elements within this angle are protected (see dia-
gram opposite).
Application Example 1
Protective angle method for a single-family house with pitched roof
Planning an interception system
Building type
Method
Pitched roof
Protective angle method
see Application Example 1
Flat roof
Loop method
see Application Example 2
Flat roof
with structures
Loop method combined with
the protective angle method
for the structures
see Application Example 3
Protected area
1
1
2
3
178 TBS
For tabulated illustration of protective area, see page 180 h
Step 3:
Building elements outside of the protective angle
Building elements outside of the protective angle must
be protected separately. The chimney in our example
has a diameter of 70 cm and therefore requires a 1.50
m long lightning rod. In this case, observe the length
diagonals. (Data for the height of the lightning rods
and a precise calculation are contained on pages
180183.) Dormer windows have their own ridge con-
ductor.
Step 4:
Completing the interception system
Take the interception system down to the arrester
equipment. The ends of the ridge conductor should
protrude and curve upwards by 0.15 m. This also pro-
tects any projecting canopies.
Max. 1.2 m
Max. 1.2 m
0.4 m
Result: perfect lightning protection
system on a building with pitched roof.
0.15 m
179
TBS
Please observe
diagonals.
Pipe clamps
from page 212
Vario rapid connector
from page 202
Roof conductor
holders for ridge tiles
from page
192
Roof conductor holders from page 192
Round conductor
from page 186
Gutter clamps
from page 209
Lightning rods
from page 191
Clamping stands
from page 211 Material
e. g. of the
parapet
plate
Thick-
ness (t)
mm
Thickness (t)
with no risk of melting, overheating or
ignition at the low end of the strike
mm
Fe
0.5
4
Cu
0.5
5
0.65
7
Fastening the
bridging component
(using rivets or bolts
from stainless steel)
Diameter
mm
5 blind rivets
3.5
4 blind rivets
5
2 blind rivets
6
2 plate screws
6.3
h
Step 1:
Installing the interception system Part 1
First, a round conductor is installed at all primary impact
points such as ridges, crests or edges. The protected
area is determined as follows:
Transfer the height of the building to the diagram and
read off the protective angle. In our example, this angle
is 60° with protection class and a building height up to
10 m. Transfer the protective angle to the building. All
building parts within this angle are protected.
Parapet plates as a component
of the interception system
Parapet plates can be used as a natural component of
the interception system if they have a certain minimum
thickness, as indicated in the table to the left and have
a conductive connection between them. Conductors
are connections created by hard soldering, welding,
pressing, bolting or riveting. Individual parapet plates
can also be joined via bridging components and the
corresponding screws or rivets as defined by the stand-
ard (see table, right).
Application Example 2
Loop method on an office building with flat roof
Protected area
2
Class 2
Class 3
Height of the
lightning
rod in m
Protection
area
a in m
Protection
area
a in m
1
2.9
3.4
2
5.8
6.9
3
8.7
10.4
4
10.4
12.3
5
10.7
13.7
6
11.2
14.8
8
12.8
16.4
10
13.7
18.0
12
14.3
19.2
14
15.0
19.9
16
15.4
21.2
18
15.1
21.4
20
15.0
22.2
180 TBS
Bridging components
from page 211
Roof conductor holders
from page 192
Clamping stands
from page 211
Al/Stainless steel Lightning protection class
Loop size m
I
5 x 5 m
II
10 x 10 m
III
15 x 15 m
IV
20 x 20 m
m
m
l
Step 2:
Installing the loop
A number of different loop sizes are suitable for the
particular lightning protection class of the building (see
page 154). The building in our example has building
lightning protection Class III. A loop size of m 15 x 15
m must therefore not be exceeded. If, as in our ex-
ample, the overall length l is greater than 20 m, an
expansion piece (see diagram below) must also be
integrated for temperature-controlled length change.
Protection against lateral impact
From a building height of 60 m and the risk of serious
damage (e.g. with electrical or electronic devices) it is
advisable to install a ring circuit to protect against lat-
eral impact. The ring is installed at 80% of the build-
ing´s overall height, the loop size depends as it does
in the case of roof installation on the lightning pro-
tection class, e.g. lightning protection class corres-
ponds to a loop size of 15 x 15 m.
Result: A perfectly protected building with flat roof
Table 4: Assigning the lightning protection class to the loop
size
181
TBS
20 %
> 60 m
80 %
Vario rapid connector
from page 202
Expansion pieces
from page 211
Roof conductor holders
from page 192
Conductor holder
from page 199
FangFix
from page 189
Clamping stands
from page 211
Bridging components
from page 211
Insulated interception systems
from page 214
Stands
from page 189
Lightning rods
from page 188
Round wire
from page 186
Conductor holder
from page 199 Rostock
Kiel
Hamburg
Bremen
Hannover
Magdeburg
Berlin
Halle
Leipzig
Chemnitz
Dresden
Erfurt
Dortmund
Düsseldorf
Köln
Bonn
Koblenz
Stuttgart
München
h
t
Application Example 3
Office building with roof structures
Step 1:
Protective angle method for roof structures
You have protected the flat-roof building as described in
Example 2. You must now protected all roof structures
with lightning rods. This involves observing