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HVI Lightning Protection
HVI Lightning Protection

High-voltage-resistant, insulated HVI Conductor: The application range was gradually expanded to include HVI light,
The innovation in external lightning protection DEHNcon-H, HVI long, HVI power and HVI power long. As a result,
In order to prevent dangerous flashover between components of the exter- HVI Conductors can be used for an extremely wide range of applica-
nal lightning protection system and conductive internal system components tions.
(electric lines, pipes, etc.) keeping the separation distance s is a crucial
factor when designing and implementing a lightning protection system. The separation distance is crucial
The following overview makes it easier to select the right HVI
Unique design Conductor. The criteria for this selection are the separation distance s
and the required class of LPS.
When using conventional lightning protection systems, it is often not
possible to maintain the necessary separation distances. This is no prob- The IEC 62305-3 standard requires that a defined separation distance
lem with the HVI Conductor thanks to its unique design and special be kept as a minimum distance between the lightning protection system
sheath. The lightning current carrying conductor of the HVI Conductor and electrically conductive materials. This prevents dangerous flashover
is wrapped with insulating material in such a way that the required and thus sparking, ensuring that lightning currents are reliably conduct-
separation distance from other conductive parts of the building, electric ed to the earth-termination system. The high-voltage-resistant, insulated
lines and pipes is maintained. The conductor consists of an inner copper down conductors from DEHN provide an equivalent separation distance
conductor with a high-voltage-resistant thick-walled insulation and a and thus meet the normative requirements.
weather-resistant semi-conductive special outer sheath.
The separation distance can be calculated automatically by means
Function of the HVI Conductor of the DEHNsupport Toolbox software.
High impulse voltages cause flashover on the surface of insulating mate-
rial if no additional measures are taken. This effect is also referred to as Types of HVI Conductor
creeping flashover. If the creeping discharge inception voltage is exceed- Three types of HVI Conductor are available:
ed, a surface discharge is initiated which can easily flash over a distance • HVI light, DEHNcon-H
of several meters. To prevent creeping discharges, the HVI Conductor • HVI Conductor, HVI long Conductor
features a special outer sheath which makes it possible to discharge • HVI power, HVI power long Conductor
high lightning impulse voltages to a reference potential. For functional
reasons, a connection is established between the semi-conductive outer
sheath and the equipotential bonding system of the building (no light- Each type of HVI Conductor has different strengths and characteristics
ning voltage) in the sealing end range. This connection to the equipoten- and therefore also different installation requirements. There are also
tial bonding system can be made, e.g. on earthed metal roof-mounted black and grey conductors within the HVI Conductor product line. The
structures located in the protected zone of the lightning protection additional grey sheath allows the HVI Conductor to be installed unob-
system, earthed parts of the building structure that do not carry lightning trusively on buildings.
voltage or the protective conductor of the low-voltage system.
HVI Conductor inside the supporting tube –
Types of HVI Conductor dimensioned according to Eurocode
In 2003, DEHN launched an innovation in external lightning protection, Both the material of the supporting tube and sufficient stability are cru-
the high-voltage-resistant, insulated HVI Conductor. Since then, thou- cial factors when choosing self-supporting air-termination systems with
sands of buildings and installations have been successfully equipped HVI Conductors installed inside / outside the supporting tube. The area
with HVI Lightning Protection. The large number of HVI Conductors exposed to wind is larger when HVI Conductors are installed outside
installed and intensive development work have given us the edge in the supporting tube. The standing surface and the necessary base weight
terms of experience. This is reflected in the variety of HVI Conductors. have to be considered accordingly.
These meet the differing requirements on lightning protection systems.
The gust wind speed is determined using the following parameters:
• Wind zone (I-V)
• Terrain category
Separation distance 90 cm • Object height
Class of LPS I – IV • Height of location above sea level
HVI power HVI power long (standard up to 800 m above sea level)

Separation distance 75 cm 200 kA The table lists the respective maximum gust wind speeds for self-sup-
DEHNcon-H HVI long porting air-termination systems with HVI Conductors. They have to be be
Class of LPS II – IV
compared with the defined values in the gust wind speeds table. If the

Separation distance 45 cm 150 kA max. gust wind speed for an air-termination system is lower than the
Class of LPS II – IV respective local gust wind speed, the air-termination system is suitable
for this application.
HVI black HVI grey HVI light DEHNcon-H 150 kA If necessary, permissible roof loads must be observed and coordinated with
the constructor.
2003 2004 2007 2008 2011 2013 2015
Valid as of March 1, 2020 139