65
Group A and group B are common gas groups in a data center. Group A's or group
B's concentration limitation values correspond to copper and silver reactivity level
G1.
Corrosion is not determined by a single factor, but by comprehensive
environmental factors such as temperature, relative humidity and corrosive
airborne contaminants. Any change of the environmental factors may affect the
gaseous corrosivity level. Therefore, the concentration limitation values specified in
the previous table are for reference only. If the actual mixed gas concentration is
not listed in the table, refer to chemically active substance level in IEC-60721-3-3 or
GB/T 4798.3-2007 to choose the concentration range.
4.
Mechanically Active Materials
The server room should be free from explosive, conductive, magnetism-permeable,
and corrosive dust. The table below lists the requirements for concentration of the
mechanically active materials in the server room
Table 8-9 Requirements for Concentration of Mechanically Active Materials
Mechanically Active
Materials
Unit
Concentration
Sand
mg/m
3
≤30
Suspending dust
mg/m
3
≤0.2
Dust deposit
mg/(m
2
h)
≤1.5
To meet these requirements, take the following measures in the server room:
Use dustproof materials on the ground, wall, and ceiling of the server room.
Adopt few or no windows design in the server room, and use dustproof
materials for outer windows.
Clean the server room, especially the air filters periodically.
Wear shoe covers and ESD clothing before entering the server room.
8.9
EMC Requirements
As per GB/T 17626.3(IEC 61000-4-3) & GB/T 17626.6(IEC 61000-4-6) & GB/T
17626.8(IEC 61000-4-8), the recommended electromagnetic environment is as
follows:
Table 8-10 Electromagnetic Environment
Electromagnetic Phenomenon
Specifications
Power frequency
magnetic field
Frequency (Hz)
50
A/m (rms)
≤ 1