Relative Temperature
Relative Humidity
Long-time Working
Condition
Short-time working
Condition
Long-time Working
Condition
Short-time Working
Condition
15ºC to 30ºC
0ºC to 45ºC
40%~65%
5%~95%
The ambient temperature and humidity are measured at a point 1.5 meters (4.9 feet) above the ground and 0.4
meters (1.3 feet) before the device when there is no protective board in the front or back of the rack.
The short-term working condition refers to a period no longer than consecutive 48 hours or accumulated 15 days a
year.
The extreme working condition refers to the temperature and humidity of the machine room where the air conditioner
fails for no more than five hours.
2.1.2 Cleanness Requirements
Dust poses a serious threat to device operation. Dust that falls onto the surface of the device can be absorbed onto metal
contact points by static electricity, resulting in poor contact. Electrostatic absorption of dust occurs more easily when the
relative humidity is low, which may shorten the service life of the device and cause communication failures. Table 2-2
shows the maximum concentration and diameter of dust allowed in the equipment room.
Table 2-2
Maximum Diameter (µm)
0.5
1
3
5
Maximum Content (Number of
Particles in one Cubic Meter)
1.4×10
7
7×10
5
2.4×10
5
1.3×10
5
Besides, the contents of salts, acids and sulfides in the air are also strictly limited for the equipment room. These
substances can accelerate metal corrosion and the aging of some parts. Table 2-3 describes the limit of some hazardous
gases such as SO
2
, H
2
S, NO
2
and Cl
2
in the equipment room.
Table 2-3
Gas
Average (mg/m
3
)
Maximum (mg/m
3
)
SO
2
0.2
1.5
H
2
S
0.006
0.03
NO
2
0.04
0.15
NH
3
0.05
0.15
Cl
2
0.01
0.3
2.1.3 Static Discharge Damage Prevention
Although much has been done in RG-WS6008 to prevent static electricity, great damage may be caused to the circuitry
when the static electricity exceeds a certain limit. Electrostatic induction may come from the following sources:
External electric field produced by the high-voltage supply cable, lightning, etc;
