Huawei Quidway S3526 - Cleanness Requirement

Installation Manual
Quidway S3526 Ethernet Switch Chapter 3 Installation
3-2
level in the equipment room is too high for a long time, it will lead to bad insulation of the
insulating material or even leakage. Sometimes, the mechanical performance,
changes of material, the rustiness and corrosion of some metal parts are also likely to
occur. If the relative humidity is too low, the captive screws may become loose due to
the shrinking of insulation washers. Meanwhile, the electrostatic is likely to be produced
in the dry weather environment, which will jeopardize the CMOS circuit of the switch.
Higher the temperature, the greater will be the damage caused to the switch. High
temperature for a long time will speed up the aging process of the insulation materials,
greatly lower the reliability of the switch and therefore affect its life span seriously.
3.2.2 Cleanness Requirement
Dust will hazard safe operation of the equipment. Falling on the equipment, it may
cause electrostatic adsorption, and hence result in poor contact of the metal connectors
or connection points. This is more likely to happen when the relative indoor humidity is
low, which will not only shorten the router’s service life, but also incur communication
failures.
The requirements on dust content and particle diameter in the equipment room are
shown in the following Table.
Table 3-1 Specification on dust content in an equipment room
Maximum diameter (µm) 0.5 1 3 5
Maximum intensity (particles per cubic meter) 1.4 x 10
7
7 x 10
5
2.4 x 10
5
1.3 x 10
5
Besides the requirements on dust, rigorous requirements are also set on the air content
of salts, acids, and sulfides in an equipment room. These harmful gases will accelerate
metal corrosion and aging process of certain parts. The equipment room should be
protected from harmful gases such as SO
2
, H
2
S, NO
2
, NH
3
and Cl
2
, the value limits of
which are shown in the following Table.
Table 3-2 Value limits for harmful gas contents in an equipment room
Gas Average (mg/m
3
) Maximum (mg/m
3
)
SO
2
0.2 1.5
H
2
S 0 0.03
NO
2
0.04 0.15
NH
3
0.05 0.15
Cl
2
0.01 0.3