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in the metal mast. If this is not possible, the camera cable must
IP camera camera PC be routed in a metal tube and conductively connected to the
mast. In this case, surge protective devices do not have to be
installed in the junction box if the cable length does not ex-
ceed some metres.
junction box Lightning equipotential bonding must be established at the
entrance point into the building for all cables mentioned above
which are routed from the junction box at the mast to a build-
ing with external lightning protection system (Table 9.7.1).
If cameras are mounted on the outer façade of a building, it
junction box should be ensured that the camera is located in the protected
volume or is protected from direct lightning strikes by an air-
termination system.
LAN cable
Building without external lightning protection
Figure 9.7.3 IP camera with surge protective devices on both ends system
If buildings are not equipped with an external lightning protec-
tion system, the risk resulting from a direct or nearby lightning
Building with external lightning protection system strike to the building is assumed to be low and is thus accept-
Figure 9.7.1 shows a CCTV camera installed at a mast. A di- able. In this case, the installation of surge arresters provides
rect lightning strike to the camera can be prevented if an air- sufficient protection (Table 9.7.1).
termination rod is installed at the mast. The connecting cable Figure 9.7.2 shows a multi-line CCTV system and Figure
between the junction box and the camera is typically installed 9.7.3 a digital IC camera system.

No. Protection for… Surge protective device Part No.
Surge protective devices for information technology systems
BLITZDUCTOR XT / BLITZDUCTOR SP 920 271 / 926 271
Two-wire cable (video transmission)
+ BXT BAS 920 300
UGKF BNC or 929 010
Coaxial cable (video transmission system)
DGA BNC VCID 909 711
BLITZDUCTOR XT / BLITZDUCTOR SP 920 271 / 926 271
RS 485 cable (camera controller)
+ BXT BAS 920 300
DPA M CLE RJ45B 48 929 121
LAN cable (IP camera)
DPA M CAT6 RJ45H 48 929 110
Surge protective devices for power supply systems – Surge arresters
a.c. TN system DEHNguard DG M TN 275 952 200
a.c. TT system DEHNguard DG M TT 2P 275 952 110
Surge protective devices for power supply systems – Combined arresters
a.c. TN system DEHNshield DSH TN 255 941 200
a.c. TT system DEHNshield DSH TT 255 941 110
Table 9.7.1 Surge protective devices shown in Figures 9.7.1 to 9.7.3

302 LIGHTNING PROTECTION GUIDE www.dehn-international.com