AP7052DN&AP7152DN
Hardware Installation and Maintenance Guide
5 Appendix
Issue 01 (2017-12-29)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
127
No.
Description
less than 1.6 sq. mm (0.002 sq. in.).
4
Ensure that all metal components of the cabinet conduct well. No insulating
coating should be sprayed on the connection part of the metal components.
5
Connect the cabinets in the same row by fastening captive screws and gaskets on
the top of the cabinets. Do not spray any coating into a rectangular area measuring
30 mm x 50 mm (1.18 in. x 1.97 in.) around the connection hole for a captive bolt.
Measures to prevent rust and corrosion must be taken for this area. Zinc
electroplating with iridescent yellow chromate conversion coating should be
applied to the gasket and nut to ensure good electrical contact.
6
When combining cabinets of the same type, short-circuiting cables are required to
connect the ground busbars (if any) of the cabinets. The cross-sectional area of the
short-circuiting cable is 6 sq. mm (0.009 sq. in.) and is no more than 300 mm (11.8
in.) long. Connect the two ends of the short-circuiting cable to the ground busbar
terminals of neighboring cabinets and fix them firmly.
5.3.4 Grounding Specifications for Communications Power
Supply
Table 5-23 shows the grounding specifications for communication power supplies.
Table 5-23
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 5-24 lists the grounding specifications for signal cables.