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Isolated lightning protection α α

Note: Observe grandfathering clause air-termi-
nation tip
sealing
end range
GRP/Al supporting tube antenna cable
earthing acc. to DIN VDE 0855-300
air-termination system
low-voltage feeder cable
RBS
sealing end
HVI Conductor III

bare down conductor equipotential bonding conductor
Figure 5.2.4.13 Integration of an antenna in an existing lightning protection system by means of a HVI Conductor

lation of the cell site must not present an additional risk for
the building.

For the lightning protection system this means that no partial
lightning currents may enter the building in case of a lightning
strike to the radio tower since partial lightning currents inside
the building would threaten the electrical and electronic de-
vices.
For this reason, the radio tower must be installed in conjunc-
tion with an isolated air-termination system and an insulated
down conductor (Figure 5.2.4.13). Thanks to this structure
which is fixed at the antenna standpipe, areas exposed to wind
are kept to a minimum (HVI Conductor integrated in the sup-
porting tube) and additional mechanical stress on the antenna
standpipe is minimised (Figure 5.2.4.14).

Use of HVI Conductors for thatched roof
Due to their specific fire load, thatched and soft roofs pose a
special challenge for installing a lightning protection system.
If these highly flammable materials are used, separation dis-
tances must be maintained from these objects. HVI Conduc-
tors are also suited for installation on soft roofs. Uncontrolled
flashover to installations is prevented since the lightning cur-
rent is separately conducted to the earth-termination system.
In addition, this solution meets architectural requirements. For
more detailed information on thatched roofs, please refer to
chapter 5.1.5. Figure 5.2.4.14 HVI Conductor installed on a radio tower

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