R240D
Hardware Installation and Maintenance Guide
5 Appendix
Issue 03 (2016-01-26)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
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5.2.2 Requirements for Power Supply
Requirements for AC Power Supply
An AC power supply system consists of power mains, uninterruptible power supplies (UPSs),
and self-supplied electric generators. In addition to meeting the requirements of the server
load, the AC power supply must have a simple connection line, safe operation, flexible
scheduling, and easy maintenance.
The low-voltage power supply should be 3-phase, 5-wire mode or monophase 3-wire mode.
This AC power supply should be 110 V/220 V, with a frequency of 50 Hz.
The UPS should supply the same power and operate at the same phase as the power mains.
The switching time between the UPS and mains should be less than 10 ms; otherwise, the
networking devices will reboot or reset.
For power distribution capacity in the equipment room, both the working current and fault
current of the devices should be considered. Ensure that independent AC power supplies
protect independent devices. Configure the current-carrying capacity of the protection switch
of the equipment room for more than that of the devices.
Table 5-14 lists the voltage range of the AC power supply for the devices.
Table 5-14
Voltage range of AC power supply
Item
Requirements
AC power capacity to
support the devices
-10% to +5% of the rated voltage
AC power capacity to
support the power modules
and important buildings
-15% to +10% of the rated voltage
Frequency of alternating
current
-4% to +4% of the rated value
Voltage wave shape sine
distortion
Within 5% of the rated voltage
The automated electric generator must have a standard interface that supports
telecommunication protocols, remote telecommunication, monitoring, and control.
AC power cables should meet the following specifications:
AC neutral should have a conductor with the same cross section as the phase line.
AC cables should have non-flammable insulation. The layout of AC cables should
comply with local regulations. Low-voltage power distribution rooms should comply
with local regulations.
Recommendations for AC Power Supply
The following are recommendations for the AC power supply.