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No. in 9.17.3 Protection Type Part No.
a.c. power supply
Base station (230/400 V a.c.) DEHNvap CSP 3P 100 FM 900 360
d.c. power supply
Power supply unit (48 V d.c.) DEHNsecure DSE M 1 60 FM 971 126
Remote radio head (48 V d.c.) DEHNsecure DSE M 2P 60 FM 971 226
Fixed-line connection
BLITZDUCTOR XT BXT ML4 B 180 920 310
Telecommunication lines
+ BXT BAS base part 920 300
External lightning protection
Ground-mounted system / roof-mounted system Equipotential bonding bar, 10 terminals 472 219
Ground-mounted system / roof-mounted system HVI Conductor III 819 025
Ground-mounted system / roof-mounted system GRP/Al supporting tube 105 300
Ground-mounted system / roof-mounted system Terminal plate 301 339

Ground-mounted system / roof-mounted system Pipe clamp for antennas 540 100
Ground-mounted system Stainless steel terminal bracket 620 915
Ground-mounted system Stainless steel earth rod 620 902

Table 9.17.1 Lightning and surge protection for cell sites

In case of both types of installation, the d.c. feeder cables and tegrated in the antenna earthing as per IEC 60728-11
system technology are exposed to lightning currents in the (EN 60728-11) and, if a lightning protection system is installed
event of a direct lightning strike. on the building, as per IEC 62305-3 (EN 62305-3).
Thus, lightning current and surge arresters must be capable Type 1 d.c. arresters with a low voltage protection level
of safely conducting lightning currents to the earth-termina- that are specifically developed for RRH / RRU applications
tion system. To this end, type 1 lightning current arresters in are installed in the d.c. indoor box near the power sup-
conformity with EN 61643-11 (class I, IEC 61643-1/-11) are ply unit in the technical equipment room and in the d.c.
used. Only spark-gap-based type 1 arresters ensure reliable outdoor box at the antenna mast. The d.c. box at the mast
energy coordination with downstream protective circuits in- features a “1+1” circuit, meaning that the positive pole
tegrated in the input of terminal equipment. If spark gaps and cable shield are interconnected indirectly via a so-
are used to protect base stations, power supply units and called total spark gap to prevent corrosion and stray cur-
remote radio heads / units, lightning currents are prevented rents. In the power supply unit, the positive pole is directly
from entering system technology, thus providing maximum earthed and single-pole type 1 d.c. arresters are typically
protection and ensuring availability of the station even un- installed.
der lightning conditions (Figures 9.17.2 and 9.17.3). Prewired d.c. assembly systems (d.c. box) for indoor and
outdoor installations with DEHNsecure DSE M 1 60 FM and
Customised solutions for 48 V d.c. remote radio DSE 2P 60 FM type 1 d.c. lightning current arresters ensure
heads / units (type 1 arresters) efficient protection. The voltage protection level U p of the type 1
lightning current arresters must be lower than the dielectric
D.c. arresters: Modular DEHNsecure 60 … (FM) type 1 strength of the system technology.
lightning current arresters Benefits of the new d.c. arrester concept are, for example,
RRHs / RRUs are centrally supplied with direct current from enough leeway for future extensions of the site in case of
the service room. The shielded feeder cable must be in- nominal load currents up to 2000 A, no mains follow cur-

358 LIGHTNING PROTECTION GUIDE www.dehn-international.com