the TT
network, however, the electrical unit supplied
through the three external lines (L1, L2, L3), the neut-
ral cable (N) and the earth cable (PE).5-wire networks, TN-S and network system
In the TN-S network system, the electrical unit sup-
plied through the three external lines (L1, L2, L3), the
neutral cable (N) and the earth cable (PE). Usage de-
scribed IEC 61643-11.
System fuse F1
Cable length between arrestors
Circuit distribution board, e. sub-distributor
Final circuit
Main earthing busbar (MEB)
Local equipotential busbar (PAS), optional
Type (class lightning arrestor
Type (class II) surge protection devices (SPDs)
Type (class III) surge protection devices (SPDs)
5-wire networks, TN-S and network system
Advantages the 3+1 circuit:
•Universally suitable for and networks
•Insulating spark gap between neutral conductor (N) and earth (PE)
•Low protection level between phase (L) and neutral conductor (N)
•Use front the protection switch (RCD) also approved net-
work
TBS
Blitzschutz-Leitfaden
2018
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Chapter The internal lightning protection system
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