telecommunication load and force load. The capacity should be not less than 150% to
200% of the total uninterrupted AC power device.
l
Storage batteries are usually installed in two parallel groups. UPS storage batteries are
generally installed in one group. Redundancy required for UPS can adopt concatenation
or parallel connection. When an inverter or a UPS is used, the active inverter is
determined by the maximum power and a backup inverter is required.
A.4 Equipment Grounding Specifications
This section describes grounding specifications, including general grounding specifications,
the grounding specifications for equipment rooms, devices, communication power modules,
signal cables, and signal cables, and the specifications for laying out ground cables.
A.4.1 General Grounding Specifications
This section describes general grounding specifications.
lists the general grounding specifications.
Table A-39
General grounding specifications
No.
1
The grounding design should follow the principles of equal voltage and equal
potential. That is, the working grounding and protection grounding, including the
shielded grounding and the lightning-proof grounding of the cable distribution
frame are jointly grounded at the same group of grounding body.
2
The cabling racks, shells, metal ventilation pipes, metal doors, and windows in the
equipment room should be grounded for protection.
3
The metal parts of equipment, which are neutral in normal conditions, should be
grounded for protection.
4
The ground cable must be connected properly to the protection ground bar of the
equipment room.
5
Do not use other equipment for the component part of the ground cable or
electrical connection.
A.4.2 Grounding Specifications for an Equipment Room
This section describes the requirements for grounding the 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 the area where earth resistance rate is high
should be less than 10 ohms.
A.4.3 Grounding Specifications for the Device
This section describes the requirements for grounding the device.
HUAWEI USG9500 Series
Hardware Guide
A Appendix
Issue 03 (2017-12-15)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
477
