MP1900X Series Router Installation Manual
Appendix
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2019 Maipu, all rights reserved
C-5
easily, too.
If the relative humidity in the equipment room is too low, insulation pads shrink,
which causes the fastened screws loose. Meanwhile, in dry environment, static
electricity appears easily, which harms the circuits on the router.
C1.3 Cleanliness Requirements
Dust is harmful for the router operation. Dust causes electrostatic absorption, which
makes the poor contact of metal connectors. Electrostatic absorption appears
especially when the temperature and humidity are lower, which affects the router life
and easily causes communication fault. The requirement for the dust content and
particle diameter in the equipment room is as shown in the following table.
Appendix Table C-3 Dust requirement for equipment room
Max. diameter
(μm)
0.5
1
3
5
Maximum
density
(tablets/m
3
)
1.4×10
7
7×10
5
2.4×10
5
1.3×10
5
If there is no visible dust on the desk within three days, it meets the cleanliness
requirement.
Apart from dust, the router equipment room has the strict requirements for salts, acids,
and sulfides contained in the air, because these harmful gases speed up the eroding of
metals and the aging of some components.
We should prevent the harmful gases, such as SO2, H2S, NO2, NH3 and Cl2, from
entering the equipment room. The specific limited values are as shown in the following
table.
Appendix Table C-4 Limitations for the harmful gases in the equipment room
Gas
Max. (mg/m
3
)
SO
2
0.2
H
2
S
0.006
NH
3
0.05
