Humidity Requirements; Cleanness Requirements - H3C S12500 Installation Manual

CAUTION:
If condensation appears on the switch when you move it to a high-temperature environment, dry the switch
before powering it on to avoid short circuits.

Humidity requirements

Maintain appropriate humidity in your equipment room, as described in
Table 9 Humidity requirements
Humidity
Operating humidity (noncondensing)
Storage humidity (noncondensing)
Lasting high relative humidity tends to cause poor insulation, electricity creepage, mechanical property
change of materials, and corrosion of metal parts. Lasting low relative humidity is likely to result in loose
screws due to washer contraction, and even electrostatic discharge (ESD), which causes the circuits to
fail.

Cleanness requirements

Dust is a hazard to the operating safety of your switch. Dust buildup on the chassis may 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 10 Dust concentration limit in the equipment room
Substance
Dust particles
NOTE:
Dust particle diameter ≥ 5 μm
In addition, the equipment room should meet strict limits on salts, acids and sulfides to eliminate
corrosion and premature aging of components, as shown in
Table 11 Harmful gas limits in an equipment room
Gas
SO
2
H S
2
NO
2
NH
3
Cl
2
Range
5% to 95%
5% to 95%
Concentration limit (particles/cu m)
≤ 3 x 10 4
(No visible dust on desk in three days)
Average (mg/m 3 )
0.3
0.1
0.004
1.0
0.1
20
Table 9.
Table 1 1.
Max. (mg/m 3
1.0
0.5
0.15
3
0.3
)