A
shield the communication cable can considerably
reduce the magnitude the interference induced. with lightning
current, can assumed that the frequency will be
high and the pulse duration short. For example, 230 power
lines:
If the communication cable located inside the mag-
netic field electrical conductor, interference
voltage can induced.
Basic principle induction:
Current (I) flowing through electrical conductor
generates magnetic field all around it.
Data cable
Energy cable
Power
Frequency
Time
Inductive coupling from parallel power cable
Current-carrying conductor
Conductor loop with voltage U
Variable magnetic field
Induction surface
Induction conductor loop
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Chapter The internal lightning protection system
.
However, not only lightning current that can in-
duce interference voltages; any electrical cable carry-
ing current can this. The magnitude the in-
duced voltage varies depending the size the
magnetic field and the conductor loop inside the
magnetic field. The induced surge
voltages have the waveform 8/20 μs. The energy level
is lower than the case the 10/350 pulse. The magnitude the interfer-
ence voltage induced the communication cable de-
pends both the conductor the magnetic field,
and the structure the communication cable. electrical
conductor formed into loop and placed vari-
able magnetic field, voltage (U) can measured at
the ends the conductor. data cable, this
often results the destruction the sensitive elec-
tronic components connected it.TBS
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This induces surge voltage that can disrupt dam-
age connected electrical devices
