Item
Requirements
Grounding
resistance
l
The grounding resistance must be lower than 1 ohm.
l
The upper end of the grounding body should be at least 0.7 m (2.30
ft) over the ground. In cold areas, bury the grounding body below
the frozen ground.
l
Measure the grounding resistance periodically to ensure effective
grounding.
Routing of
signal cable
l
Do not arrange the signal cables overhead in the equipment room.
All signal cables must be led into the site underground.
l
Use the cables with a metal jacket or place them into a metal pipe if
they come out/in the equipment room.
l
Ground the idle lines inside the cable in the equipment room.
l
Signal cables should be deployed on internal walls. Do not deploy
outdoor aerial cables.
l
Keep signal cables away from power cables and surge protection
devices.
Collective
ground cable
l
Use a ground ring or ground bar for the collective ground cable.
l
Do not use aluminum cables as ground cables. Adopt measures to
prevent electrification corrosion when connecting different metal
parts together.
l
Use a copper busbar as the collective ground cable with a cross-
sectional area of no less than 120 mm
2
(0.19 in.
2
), or use the
galvanized flat steel of the same resistance. Insulate the collective
ground cable from the reinforcing steel bars of the building.
Grounding lead-
in
The grounding lead-in should be a maximum of 30 m (98.42 ft) long.
Use the galvanized flat steel with cross-sectional area of 40 mm x 4
mm (1.58 in. x 0.158 in.) or 50 mm x 5 mm (1.97 in. x 0.197 in.).
6.2.2 Requirements for Power Supply
6.2.2.1 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
AP8082DN and AP8182DN
Hardware Installation and Maintenance Guide
6 Appendix
Issue 03 (2019-04-01)
Copyright © Huawei Technologies Co., Ltd.
137
