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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If the voltage of the power mains that supply power directly to devices exceeds the rated
voltage by -10% to 5%, or exceeds the voltage range that devices can support, a voltage
regulating device or voltage stabilizing device is required.
If the mains do not supply power for the device directly, or if the mains voltage exceeds
the rated voltage by -15% to 10% or exceeds the input voltage range of the DC power
supply, a voltage regulating device or voltage stabilizing device is required.
A UPS or inverter power supply system is required to provide uninterrupted AC power to
support the telecommunication load.
If abnormalities occur on the mains, telecommunication servers should be equipped with
a self-supplied electric generator to support the key telecommunication load. The
capacity should be not less than 150% to 200% of the total uninterruptible power supply.
Storage batteries are usually installed in a parallel connection of two groups. UPS
storage batteries are generally installed in one group. The redundancy required for the
UPS can rely on 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.
Requirements for DC Power Supply
The equipment room should receive stable and reliable DC power. Deploy the power
equipment near the telecommunications equipment to make the DC feeder as short as possible.
To reduce power consumption and installation cost, the loop voltage drop from the battery
port to the equipment port should be less than 3.2 V.
A large-scale enterprise can deploy an independent power supply system on each floor to
supply power to the telecommunications equipment room on the respective floor.
A medium-scale enterprise can use a power room and a battery room for centralized
power supply or use distributed power supply systems.
A small-scale enterprise can deploy an integrated power supply system in its equipment
room but must take measures to prevent corrosive gases released from batteries from
eroding circuit boards of telecommunications equipment.
Table 5-15 lists the specifications for the DC power supply.
Table 5-15
Specifications for the DC power supply
Item
Requirements
DC power
capacity to
support the surge
current
Greater than 1.5 times the rated current
Regulated
voltage precision
If the AC input voltage is in the range of 85% to 110% of the rated
value, and the load current is in the range of 5% to 100% of the rated
value, the output voltage of the rectifier ranges from -46.0 V to -56.4 V,
with the regulated voltage precision less than or equal to 1%.
Overshoot
amplitude of
switch on/off
Integral value of the DC output voltage ±5%
Peak noise
voltage
≤200 mV