QSW-4700 Series Switches Hardware Installation and Reference Guide
Preparing for Installation
52
•
In an environment with low relative humidity, static electricity is prone to occur and
damage the internal circuits of the switch.
•
Too high temperatures can accelerate the aging of insulation materials, greatly reducing
the reliability of the switch and severely affecting its service life.
Temperature and Humidity
Temperature
Relative Humidity
0ºC to 45ºC (32ºF to 113ºF)
10% to 90% (non-condensing)
Note:
•
The ambient temperature and humidity of the switch are measured at the point that is
1.5 m (59.06 in.) above the floor and 0.4 m (15.75 in.) before the switch rack when there
is no protective plate in front or at the back of the rack.
2.2.3. Cleanliness Requirements
Dust poses a major threat to the switch. The indoor dust takes on a positive or negative static
electric charge when falling on the switch, causing poor contact of the metallic joint. Such
electrostatic adhesion may occur more easily when the relative humidity is low, not only
affecting the service life of the switch, but also causing communication faults. The following
table describes the requirements for the dust content and granularity in the equipment room.
Dust
Unit
Content
Dust particles (diameter
≥ 0.5 μm)
Particles/
m3
≤ 3.5×10
6
Dust particles (diameter
≥ 5 μm)
Particles/
m3
≤ 3×10
4
Apart from dust, the salt, acid, and sulfide in the air in the equipment room must meet strict
requirements. These harmful substances will accelerate metal corrosion and component aging.
Therefore, the equipment room should be properly protected against the intrusion of harmful
gases, such as sulfur dioxide, hydrogen sulfide, nitrogen dioxide, and chlorine gas.
Gas
Average (mg/m
3
)
Maximum (mg/m
3
)
Sulfur dioxide (SO
2
)
0.3
1.0
Hydrogen sulfide (
H
2
S
)
0.1
0.5
Nitrogen dioxide (NO
2
)
0.5
1.0
Chlorine gas (CI
2
)
0.1
0.3
Note:
•
The Average refers to the average limit of harmful gas in one week. The Maximum value
is the upper limit of the harmful gas measured in one week for up to 30 minutes every
day.
