l
Keep non-antistatic materials (such as household bags, foams, and rubbers) at least 30
cm away from boards and ESD-sensitive components.
A.3.8 Electromagnetism Requirements for the Equipment Room
All sources of interference, whether from outside or inside the equipment or application
system, will influence equipment negatively in the conduction patterns of capacitance
coupling, inductance coupling, electromagnetic wave radiation, and common impedance
(including grounding system) coupling. To prevent interference, take the following measures:
l
Take effective measures against electricity net interference with the power supply
system.
l
Do not use the working ground of the equipment together with the grounding or
lightning protection grounding device of the power equipment. Separate them as much as
possible.
l
Keep the equipment far away from strong power wireless launchers, radar launchers, and
high frequency and high-current equipment.
l
Use electromagnetic shielding as necessary.
A.3.9 Requirements for Lightning Proof Grounding
describes requirements for lightning proof grounding.
Table A-36
Requirements for lightning proof grounding
Item
Requirements
Capital
construction
Use reinforced concrete in equipment room construction
Install the lightning proof device like a lightning rod in the room.
The lightning proof ground shares the same grounding body with the
room's protection ground.
TN-S power
system
Use a special power transformer on the telecommunication site. Use a
metal jacket or steel tube to cover the power cables before burying
them under the ground. Properly ground both ends of the metal jacket
or steel tube nearby with the buried length less than 15 m.
Install a gapless zinc oxide arrester to each of the three phase lines at
the low-voltage side of the AC power transformer. Nearby, properly
ground the transformer enclosure, the neutral lines at the low-voltage
side, and the metal steel tubes of the power cables that are connected to
the transformer enclosure.
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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