A.3.5 Power Supply
Normal power supply is the prerequisite for proper running of the USG. This section
describes the requirements for power supply.
Basic AC Power Supply
The AC power supply system that consists of mains, uninterruptible power supply (UPS), and
self-provided generators should supply power in centralized mode. The power supply system
should meet the needs of the communications station, and its cabling should be as simple as
possible to facilitate operation and maintenance. The low-voltage AC power supply system
should use 3-phase 5-wire or 1-phase 3-wire for power supply.
lists the low-
voltage AC nominal voltage and frequency.
Table A-19
AC voltage and frequency
Nominal Voltage
Rated Frequency
110/127/220 (V)
50Hz/60Hz
In common cases, the UPS serves as the backup power supply for network products. The
backup power supply must be the same as the mains in phases, and the duration for the
switchover between the UPS and the mains should be less than 10 ms. Otherwise, the device
might restart or be reset. Each device must have an independent AC surge protector. The
capacity of the surge protector for the power distribution room must be greater than the sum
of the operating current and fault current on the devices to be powered. The DC power supply
system must be able to safely withstand the maximum load of the device, regardless of
whether the device is in working or standby state. The wire type and gauge of each outlet of
the power distribution panel must be able to withstand the maximum power load of the
devices. The specifications for the AC power supply voltage of all communications and
power supply devices are as follows:
l
Communications devices must be equipped with AC power supply with the rated voltage
ranging from +5% to -10%.
l
Communications power supply devices and key constructions must be equipped with AC
power supply with the rated voltage ranging from +10% to -15%.
l
The frequency of the AC power current ranges from +4% to -4%, and the sinusoidal
distortion rate of voltage waveform must be 5% or less.
The self-provided generator sets in the communications station must be automatic in
activation, deactivation, and replenishment, be equipped with remote signaling, remote
measurement, and remote control, and provide standard interfaces and communications
protocols.
The power cables used for AC and DC power distribution should comply with the following
specifications:
l
The AC neutral for communications purposes must be a conductive wire that has the
same cross section as the phase cable.
l
The selection of the DC power feeder depends on the long-term load. If the cross-
sectional area is greater than 95 mm
2
, use the rigid busbar. If the short-term load differs
greatly from long-term load, lay out the cables by stages.
HUAWEI USG6000 Series
Hardware Guide
A Appendix
Issue 08 (2017-06-30)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
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