Item
Requirements
Lightning
arrester
requirements
(for power
cables leading in
the
communications
site)
Do not lead the AC/DC power cables in/out the communications site in
aerial mode.
After the low-voltage power cables are led into the room, install the
lightning arrester for the power cables in the AC voltage stabilizer and
the AC power distribution panel (box). Properly ground the arrester
nearby.
For equipment rooms in mountain areas that are susceptible to lightning
strike and equipment rooms in separate high-rise buildings cities, install
a power supply arrester with a nominal discharging current larger than
100 kA.
The PGND cable of the lightning arrester should not exceed 1 m in
length.
Grounding of
DC power
distribution
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 PGND cable nearby. The PGND cable should meet
maximum load requirements for the equipment.
The power equipment must have a DC working PGND cable, which
can connect the power equipment to the collective PGND cable of the
telecommunication site (or the protection ground bar of the equipment
room).
Equipotential
connection
Properly ground the devices and auxiliary devices in the room such as
mobile base station, transmission, switching equipment, power supply
equipment, and cable distribution frame. Connect all protection PGND
cables to the collective protection ground bar. Connect all protection
PGND cables in one equipment room to one protection ground bar.
Apply joint grounding to the working ground and protection ground of
devices such that the two share one grounding network.
The cabling rack, shell, metal ventilation pipe, metal door, or window
on the equipment should be grounded for protection.
General
grounding
Do not connect the neutral line of the AC power cable with the
protection ground of any telecom equipment in the equipment room.
Do not install the fuse or switch on the PGND cable.
All PGND cables should be as short and routed as straight as possible.
Grounding
resistance
The grounding resistance must be lower than 1 ohm.
The upper end of the grounding body should be at least 0.7 m above the
ground. In cold areas, bury the grounding body below the frozen
ground.
Measure the grounding resistance periodically to ensure effective
grounding.
HUAWEI USG9500 Series
Hardware Guide
A Appendix
Issue 03 (2017-12-15)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
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