Installation Manual
H3C S9500 Series Routing Switches
Chapter 2 Installation Preparations
2-5
Table 2-4
Harmful gas limits in an equipment room
Gas
Average (mg/m³)
Max. (mg/m³)
SO
2
0.3 1.0
H
2
S 0.1 0.5
NO
2
0.004
0.15
NH
3
1.0 3
Cl
2
0.1 0.3
2.2.4 EMS Requirements
Any possible interference sources, no matter whether outside or inside the system,
affect the switch in use through capacitive coupling, inductive coupling,
electromagnetic radiation, common impedance (including the grounding system)
coupling or conducting line (power line, signalling line and transmission line etc). To
prevent the interference, you should:
z
Take effective measures against electrical net interference for power supply
system.
z
Separate the working ground of the switch from the grounding device of the power
supply equipment or lightning-protection grounding device as far as possible.
z
Keep the switch far away from the radio launcher, radar launcher, and
high-frequency devices working in the high current.
z
Adopt electromagnetic shielding if necessary.
Note:
If necessary, take electromagnetic shielding measures against the interference.
2.2.5 Grounding Requirements
A good grounding system is not only the basis essential to the stable and reliable switch
operation, but also an important guarantee of lightning protection, anti-interference and
ESD-prevention. The user must provide good grounding system for the switch. The
resistance between the chassis and the ground must be less than 1 ohm.
2.2.6 Power Supply Requirements
The following tables describe the specifications for AC and DC PSUs.