AP7052DN&AP7152DN
Hardware Installation and Maintenance Guide
5 Appendix
Issue 01 (2017-12-29)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
126
5.3 Equipment Grounding Specifications
5.3.1 General Grounding Specifications
Table 5-21 shows the general grounding specifications.
Table 5-21
General grounding specifications
No.
Description
1
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.
2
The cable trays, shells, metal ventilation pipes, metal doors and windows in the
equipment room should be grounded for protection.
3
The metal parts of the equipment which are electrically floating in normal
conditions should be grounded for protection.
4
The ground cable must be connected securely to the protective ground bar of the
equipment room.
5
Do not use other equipment as part of the ground cable or electrical connection.
5.3.2 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.
5.3.3 Grounding Specifications for Devices
Table 5-22 lists the equipment grounding specifications.
Table 5-22
Equipment Grounding Specifications
No.
Description
1
All communication devices and auxiliary devices (such as mobile base stations,
transmission and switching devices, power supply devices) in the equipment room
should be grounded for protection. Connect all protective ground for various
devices jointly to a general ground bar, and then to the same protective ground bar
in the room together with the protective ground (PGND) of the device.
2
The PGND of the equipment is shorted to the copper ground bar provided by the
customer. The short-circuiting cable used should be a yellow-green plastic
insulated cable with a copper core and a cross-sectional area greater than 25 sq.
mm (0.039 sq. in.).
3
There are grounding terminals and grounding lugs at the lower part of the front
door, rear door and side panel of the cabinet, connected to the grounding terminals
of the cabinet framework through connection cables with cross-sectional area of no
