H3C S7502 Ethernet Switch Installation Manual

Installation Manual
H3C S7502 Ethernet Switch Chapter 3 Installation Preparations
3-4
contact between connectors or metal contact points. This happens more frequently
when the relative indoor humidity is low, which will not only shorten the service life of
the switch, but also cause communication failures.
The required specifications on dust density and particle diameter in an equipment room
are shown in the following table.
Table 3-2 Required specifications on dust density in an equipment room
Mechanical active
material
Concentration limit (particles/m³)
Dust particle ≤3 x 10
4
(No visible dust on desk over three days)
Note: Dust particle diameter ≥ 5µm
Except the requirements on dust, rigorous requirements on ingredient of salts, acids
and sulfides of air in an equipment room are also set. These harmful gases will speed
up the metal corrosion and the aging processes of certain parts. The equipment room
should be protected from the invasion of harmful gases such as SO
2
, H
2
S, NO
2
, NH
3
and Cl
2
, the value limits of which are shown in Table 3-2:
Table 3-3 Limits on harmful gas ingredients in an equipment room
Gas Max. (mg/m3)
SO
2
0.2
H
2
S 0.006
NH
3
0.05
Cl
2
0.01
3.2.3 Anti-static Requirements
Any possible interference sources, no matter outside or inside the system, affect the
switch in use may in a way of capacitance coupling, inductance coupling, radiation of
electromagnetic wave, common impedance (including the grounding system) coupling
or conducting line (power line, signaling line and transmission line etc.).Therefore, the
following should be considered:
z Adopt effective measures to protect the power supply system against the power
grid interference.
z Separate the working ground of the switch from the ground device of the power
supply equipment or lightning-protection ground device as far as possible.
z Keep the switch far away from the radio launcher, radar launcher, and
high-frequency devices working in high current.
If necessary, adopt electromagnetic shield.