H3C S5100-SI series Quick Start Manual page 59

Quick Start
H3C S5100-SI/EI Series Ethernet Switches
Caution:
You should properly connect the switch grounding wire since it is
crucial to the lightning protection and electromagnetic shield (EMS) of
your switch.
The power input end of the switch is connected with a noise filter,
whose central ground is directly connected to the chassis, forming the
so-called chassis ground (commonly known as PGND). This chassis
ground must be securely connected to the earth so that the faradism
and leakage electricity can be safely released to the earth, enhancing
the EMS capability of the switch.
Ground the switch as follows:
When a grounding strip is available at the installation site, attach
one end of the yellow-green grounding wire of the switch to the
grounding screw on the grounding strip and fasten the captive nut.
(Note that the fire main and lightning rod of your building are not
suitable for grounding the switch. The grounding wire of the switch
should be connected to the construction engineering ground of the
equipment room.)
Chapter 3 Installing the Switch
3-28