AP4050DN-HD
Hardware Installation and Maintenance Guide
5 Appendix
Issue 01 (2016-04-15)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
84
Table 5-18
Grounding specifications for communication power supplies
No.
Description
1
The inlet for the AC power cable at the equipment room should be equipped with a
surge protection device (C-level) with a nominal discharge current no less than 20
kA.
2
The protective ground for the power supply and that for communication equipment
share the same grounding conductor. If the power supply and the equipment are in
the same equipment room, use the same protective ground bar for them if possible.
3
Use a surge protection circuit on the AC power interface.
4
The positive of the -48 V DC power supply or negative pole of the 24 V DC power
supply should be grounded at the output of the DC power supply.
5
The working ground and protective ground of the DC power supply equipment
should use the same grounding conductor with the protective ground of the
switching equipment. If the power supply and equipment are in the same
equipment room, use the same protection ground bar for them if possible.
6
Add surge protection on the DC power interface.
5.3.5 Grounding Specifications for Signal Cables
Table 5-19 lists the grounding specifications for signal cables.
Table 5-19
Grounding specifications for signal cables
No.
Description
1
Equip the cable outdoors with a metal jacket, well grounded at both ends, or
connect the ends of the metal jacket to the protective ground bar of the equipment
room. For cables inside the equipment room, install surge protection devices at the
interface to the equipment. The PGND cable for the surge protection devices
should be as short as possible.
2
The incoming and outgoing signal cables to and from the office and unused wires
inside the cable should be grounded for protection.
3
The Tone & Data Access (TDA) cable must pass through the Main Distribution
Frame (MDF) with surge protective device (SPD) when going out of the office.
The cable's shield layer should be connected to the protective ground of the MDF.
The MDF should use the same grounding conductor as the cabinet.
4
Do not route signal cables overhead.
5.3.6 Specifications for Laying Out Grounding Cables
Table 5-20 shows the specifications for the ground cable.