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Chapter 1
Design-in
1.1 Design-in guidelines
Design engineers can easily include the lightning sensor to all types of wind turbines.
All strikes that hit's a turbine construction will pass the bottom of the tower. he lower 10-15 meters of the
tower is seen as safe installation area (rolling sphere model).
For towers made of concrete material and steel wires, please contact Jomitek for special and free advise.
he 2 antennas has to be placed on opposite sides of the tower. he signal from the two antennas is
summarized in the antenna box. Any strike current that passes inside the tower or through the tower wall
will be measured by the magnetic field generated. By having the antennas 180 degrees from each other,
any strike in nearby turbines will generate a pulse that will have opposite sign in the 2 antennas and
thereby become subtracted and will then not be able to generate an alarm. his gives a design rule of
thumb:
1 Place the 2 antennas 180 degrees +/- 5 degrees from each other
he magnetic field generated will form circular field lines around the tower and flow through the
antennas. It is important that these field lines will not become disturbed so the next rule:
2 Place the antennas at a level where no other iron part will disturb the cirkle +/- 1 meter
in the horizontal plane
If something big, like a platform structure or a transformer is placed nearby, please ask Jomitek
for an evaluation of the actual placement and disturbances.
o make sure that the magnetic field lines will not induce a damaging high voltage between the
antenna wires and other metal parts the wires should:
3 Place antenna wires in a horizontal plane +/- 0,5 meters of the antenna level
As any metallic surrounded hole perpendicular to the current direction will generate a voltage
when strike passes a rule that must apply inside the tower as well as outside the tower is:
4 Antenna wires must be kept as close to the tower wall as possible and preferable within
10cm
o make sure that the summation of the antenna signals works well it is preferred that
5 The antenna wires must be approx the same length for each of the 2 antennas
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Jomitek ApS – Electrical Engineering
Skovlytoften 22, DK-2 40 Holte
Tel. +45 45 46 14 15
Fax +45 45 46 14 16
CVR-nr. 20 01 99 72
