impedance (including grounding system) coupling. Prevent the interference using these
approaches:
l
Take effective measures against electrical interference from the power supply system.
l
Do not use the working ground of the equipment as the same ground for lightning protection.
Separate them as far as possible.
l
Keep the equipment far away from strong power radio transmitters, radar units, and high-
frequency and high-current equipment.
l
Use electromagnetic shielding if necessary.
B.1.9 Requirements for Lightning Proof Grounding
shows the requirements for lightning proof grounding.
Table B-5
Requirements for lightning proof grounding
Item
Requirements
Capital
construction
Use the reinforced concrete structure for the construction of the
equipment room.
Install the lightning proof device like a lighting rod in the room.
The lightning proof ground shares the same grounding body with the
protection ground of the room.
A TN-S power
system shall be
adopted.
Use a special power transformer for the telecommunication site. Use the
metal jacket or steel tube to cover the power cables before burying them
under the ground. Ground both ends of the metal jacket or steel tube
nearby and properly with the buried length less than 15 m (49.21 ft).
Install a gapless zinc oxide arrester to each of the three phase lines at the
low-voltage side of the AC power transformer. Ground nearby and
correctly the enclosure of the transformer, the neutral lines at the low-
voltage side, and the metal steel tubes of the power cables that are
connected to the enclosure of the transformer.
Power cables
leading in the
communications
site need to be
equipped with a
lightning
arrester.
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). Ground the arrester nearby and
correctly.
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.
The ground cable of the lightning arrester should be a maximum of one
meter (3.28 ft) long.
HUAWEI NetEngine80E Router
Installation Guide
B Environmental Requirements for Device Operation
Issue 02 (2011-09-10)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
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