To avoid short circuits, if condensation appears on the chassis when you move it to a high-temperature
environment, dry the chassis before powering it on.
To ensure correct operation of the switch, make sure the room temperature meets the requirements
Table 2 Temperature requirements
Maintain appropriate humidity in your equipment room, as described in
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
ESD, which causes the circuits to fail.
Table 3 Humidity requirements
Dust buildup on the chassis might result in electrostatic adsorption, which causes poor contact of metal
components and contact points. In the worst case, electrostatic adsorption can cause communication
Table 4 Dust concentration limit in the equipment room
Dust particle 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
0°C to 45°C (32°F to 113°F)
–40°C to +70°C (–40°F to +158°F)
10% to 95%, noncondensing
5% to 95%, noncondensing
Concentration limit (particles/m
≤ 3 x 10
(No visible dust on desk in three days)