HP 1920 Series Getting Started Manual page 6

The accessories shipped with the switch, including but not limited to power cables, are intended
•
only for the switch. Please do not use them for other products.
Examining the installation site
The switches must be used indoors. You can mount your switch in a rack or on a workbench, but make
sure:
A minimum clearance of 5 cm (1.97 in) is reserved at the air inlet and exhaust vents for ventilation.
•
The rack or workbench has a good ventilation system.
•
• The rack or workbench is sturdy enough to support the switch and its accessories.
The rack or workbench is reliably grounded.
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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
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.
Cleanness
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 2 Dust concentration limit in the equipment room
Substance
Dust
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 3 Harmful gas limits in the equipment room
Gas
SO
2
H S
2
Concentration limit (particles/m³)
≤ 3 x 10 4 (no visible dust on the tabletop over three days)
Table 3.
Maximum concentration (mg/m
0.2
0.006
2
"Environmental
3 )