current
loops. The maximum operating current should also be
verified ensure that the dissipated energy does not
cause thermal destruction the decoupling elements.
Ground-referenced systems are signal circuits that
have common reference potential with other signal
circuits. FLD/FLD2 an-
d/or MDP devices should therefore used this
case. The decision use FRD
(with resistive decoupling) FLD (with inductive de-
coupling) depends the system protected. These are systems
whose signal circuits have common reference po-
tential with other signal circuits, e. These devices can universally applied. Therefore, when used measuring cir-
cuits with high transfer frequencies, lightning barriers
with resistive decoupling elements are the preferred
solution. This can result er-
rors with current loop measurements.
In the case arrestors with integrated inductances for
decoupling, the signal attenuated high transfer
frequencies.
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
238
Chapter The internal lightning protection system
. these systems, two further data cables be-
sides earth are protected.Circuit diagram lightning barrier FRD/FLD
Circuit diagram lightning barrier FRD2/FLD2
Type series FRD/FLD
Type FRD, FLD and MDP lightning barriers are de-
signed for use so-called floating (asymmetrical, po-
tential-free) two-core systems.
Type series FRD2/FLD2
Type FRD2 and FLD2 are intended for use ground-
referenced (symmetrical, potential-referenced) single-
wire systems.
Basic protection circuit measuring circuit
Use lightning barriers measuring circuits
Before lightning barriers are used measuring cir-
cuits, must first confirmed whether resistance
increase permitted. Depending the decoupling,
resistance increases the measuring circuits can oc-
cur with types FRD and FRD2.g
