Appendix D Equipment Grounding Specifications; General Grounding Specifications; Grounding Specifications For An Equipment Room - Huawei S2700 Hardware Installation And Maintenance Manual

S2700&S3700&S5700&S6700 Switch
Hardware Installation and Maintenance Guide
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13.4 Appendix D Equipment Grounding Specifications

13.4.1 General Grounding Specifications

Table 13-33
Table 13-33 General grounding specifications
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13.4.2 Grounding Specifications for an Equipment Room

The grounding resistance of a comprehensive communication building should be less than or
equal to one ohm. The grounding resistance of an ordinary communication office should be
less than five ohms. The grounding resistance in an area where the earth resistance rate is high
should be less than 10 ohms.
Issue 13 (2017-11-20)
Use distributed power supply mode. Use multiple DC power supply systems and put
power equipment in multiple locations.
Adopt a standard DC power supply system, and set the output voltage to the
communications equipment within the required range.
Improve reliability of the AC power supply system to reduce the necessary capacity of
storage batteries. For small offices, increase the capacity of storage batteries if it is
difficult to enhance reliability of the AC power supply system.
The total capacity of the high-frequency switching rectifier must satisfy the power of the
communication loading and battery charging. If there are 10 or fewer active rectifier
modules, configure one backup module. If there are more than 10 active modules,
configure one backup module for every 10 active modules.
Install storage batteries in two or more groups. The capacity is determined by the
duration for which the storage batteries must supply power. For most offices, the
batteries should be able to supply power for at least one hour.
shows the general grounding specifications.
Description
The working ground and protective ground, including the shielded ground and the
lightning-proof ground of the cable distribution frame should share the same
grounding conductor.
The cable trays, shells, metal ventilation pipes, metal doors and windows in the
equipment room should be grounded for protection.
The metal parts of the equipment which are electrically floating in normal
conditions should be grounded for protection.
The ground cable must be connected securely to the protective ground bar of the
equipment room.
Do not use other equipment as part of the ground cable or electrical connection.
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