H3C Technologies H3C S5130 Series Switches - Manual (Page 9)

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To ensure correct operation and long service life of your switch, install it in an environment that meets the
requirements described in the following subsections.
Temperature/humidity
Maintain temperature and humidity in the equipment room as described in "Technical specifications."
• Lasting high relative humidity can cause poor insulation, electricity creepage, mechanical property
change of materials, and metal corrosion.
• Lasting low relative humidity can cause washer contraction and ESD and bring problems including
loose captive screws and circuit failure.
• High temperature can accelerate the aging of insulation materials and significantly lower the
reliability and lifespan of the switch.
For the temperature and humidity requirements of different switch models, see " Appendix A Chassis
views and technical specifications ."
Cleanliness
Dust buildup on the chassis might result in electrostatic adsorption, which causes poor contact of metal
components and contact points, especially when indoor relative humidity is low. In the worst case,
electrostatic adsorption can cause communication failure.
Table 1 Dust concentration limit in the equipment room
Substance Concentration limit (particles/m³)
Dust ≤ 3 x 10 4 (no visible dust on the tabletop over three days)
NOTE:
Dust diameter ≥ 5 μm
The equipment room must also meet strict limits on salts, acids, and sulfides to eliminate corrosion and
premature aging of components, as shown in Table 2 .
Table 2 Harmful gas limits in the equipment room
Gas Maximum concentration (mg/m 3 )
SO
2
0.2
H
2
S 0.006
NH
3
0.05
Cl
2
0.01
EMI
All electromagnetic interference (EMI) sources, from outside or inside of the switch and application
system, adversely affect the switch in the following ways:
• A conduction pattern of capacitance coupling.
• Inductance coupling.