Within the external conductive layer
and the resistive field control layer, the current lines
can seen, which are significant for avoiding floating
discharges. Both diagrams show how the nu-
merical, time-discreet field calculation can used to
optimise the resistive field control that the current
in the field control layer can kept small pos-
sible, whilst still avoiding the formation floating dis-
charges. The value limited downward direction that
no partial lightning current can flow into the building. For this, the test-
ing arrangement used basis, which also
used for the high-voltage testing according IEC TS
62561-8 and represents the worst-case scenario.4 Potential control
For safe operation insulated conductor, meas-
ures avoid floating discharges are necessary.
Here, equipotential lines and the vertical electrical field
lines can seen. This allows optimisation the resistance
value the resistive field controller. The right-hand image uses cross-sec-
tion diagram show the current density vectors and
equipotential areas.
In upward direction, the value given the re-
quirement for effective field control. Using the numerical field calculation, the res-
istive field controller can calculated time-dis-
creet manner for the entire course the impulse
voltage.
Field diagram insulated conductor the first equi-
potential bonding terminal during type test time =
1. As
an example, the left image shows the field diagram of
this arrangement with applied impulse voltage of
1,000 the area the equipotential bonding ter-
minal.
Current density vectors resistive field control and po-
tential density insulated conductor time 1. The lower
the resistance designed be, the more effective it
is.2.2/50.2
µs the applied impulse voltage 1. potential 1,000 is
applied the internal conductor.13.2 the applied impulse voltage 1. an
induced voltage only present insulated con-
ductor when lightning strikes, resistive field control
can used avoid floating discharges.2.2/50 below
the earthed fastening clamp.
The voltage load lightning strike impulse
voltage.
TBS
Blitzschutz-Leitfaden
2018
/
en
/
2020/01/10
14:42:40
14:42:40
(LLExport_02613)
/
2020/01/10
14:42:54
14:42:54
134
Chapter The external lightning protection system
