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.
Table 3 Humidity requirements
Operating humidity (noncondensing)
Storage humidity (noncondensing)
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 4 Dust concentration limit in the equipment room
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 5 Harmful gas limits in the equipment room
All electromagnetic interference (EMI) sources, from outside or inside of the switch and application system,
adversely affect the switch in a conduction pattern of capacitance coupling, inductance coupling,
electromagnetic wave radiation, or common impedance (including the grounding system) coupling. To
prevent EMI, take the following actions:
If AC power is used, use a single-phase three-wire power receptacle with protection earth (PE) to filter
interference from the power grid.
Keep the switch far away from radio transmitting stations, radar stations, and high-frequency devices.
Use electromagnetic shielding, for example, shielded interface cables, when necessary.
10% to 95%
5% to 95%
Concentration limit (particles/cu m)
≤ 3 x 10
(no visible dust on the tabletop over three days)