User's Manual

Requirements for Lightning Proof Grounding
Table 5-13 shows the requirements for lightning proof grounding.
Table 5-13 Requirements for lightning proof grounding
Item Requirements
Capital
construction
l Use the reinforced concrete structure for the construction of the
equipment room.
l Install the lightning proof device like a lighting rod in the room.
l The
lightning proof ground shares the same grounding body with the
protection ground of the room.
Power cables
leading in the
equipment room
need to be
equipped with a
surge arrester
l After the low-voltage power cables are led into the room, install the
surge
arrester for the power cables in the AC voltage stabilizer and the
AC power distribution panel (box). Ground the arrester nearby and
correctly.
l For the equipment room in the city, install the power supply arrester
with the nominal discharging current no less than 20 kA. For the
equipment room built in the suburbs subject to lightning strike, install
the power supply arrester with the nominal discharging current larger
than 60 kA. For the equipment room in the mountain areas easily
subject to lightning strike, or in the separate high-rise buildings in the
city, install the power supply arrester with the nominal discharging
current larger than 100 kA.
l The ground cable of the surge arrester should be a maximum of 1 m
(3.28 ft) long.
Grounding of DC
power
distribution
l Connect
the DC working ground (positive pole of the -48 V DC power
supply or the negative pole of the 24 V DC power supply) with the
indoor collective ground cable nearby. The total ground cable should
meet the maximum load of the equipment.
l The power equipment must have the DC working ground cable, which
can connect the power equipment to the collective ground cable of the
telecommunication site (or the protection ground bar of the equipment
room).
Equipotential
connection
l Ground
the devices and auxiliary devices in the room such as mobile
base station, transmission, switching equipment, power supply
equipment, and cable distribution frame properly. Connect all PGND
cables to the collective protection ground bar. Connect all PGND
cables in one equipment room to one protection ground bar.
l Apply joint grounding to the working ground and protection ground
of devices, which means the two share one grounding network.
l The cable tray, rack or shell, metal ventilation pipe, metal door or
window of the equipment should be grounded for protection.
Huawei Indoor Access Points
Hardware Installation and Maintenance Guide 5 Appendix
Issue 08 (2014-04-10) Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
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