H3C CR19000-20, Installation Manual

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1-8
(64.4°F to 77°F) and the relative humidity less than 60% RH for the cold aisle and the air inlet area of
the rack.
Cleanliness
Mechanically active substances buildup on the chassis might result in electrostatic adsorption, which
causes poor contact of metal components and contact points. In the worst case, electrostatic
adsorption can cause communication failure.
Table1-3 Mechanically active substance concentration limit in the equipment room
Substance Particle diameter Concentration limit
Dust particles
≥ 5 µm
≤ 3 × 10 4
particles/m
3
(No visible dust on desk in three days)
Dust (suspension)
≤ 75 µm ≤ 0.2 mg/m 3
Dust
(sedimentation)
75 µm to 150 µm
≤ 1.5 mg/(m
2
h)
Sand 150 µm to 1000 µm
≤ 30 mg/m 3
To maintain cleanliness in the equipment room, follow these guidelines:
•
Use dustproof materials for floors and walls and use coating that does not produce powders.
•
Use double-layer glass in windows and seal doors and windows with dust-proof rubber strips.
Use screen doors and screen windows in the external side.
•
Keep the equipment room clean. If the equipment room environment is not as desired, install air
filters on the rack doors and clean the air filters regularly.
•
Wear ESD clothing and shoe covers before entering the equipment room.
Harmful gas limit
The equipment room must also meet limits on salts, acids, and sulfides to eliminate corrosion and
premature aging of components, as shown in
Table1-4 .
Table1-4 Harmful gas limits in the equipment room
Gas Maximum concentration (mg/m
3
)
SO
2
0.2
H
2
S 0.006
NH
3
0.05
Cl
2
0.01
NO
2
0.04
To control harmful gases, use the following guidelines:
•
Use environmentally friendly materials to decorate the equipment room. Avoid using materials
that contains harmful gases, such as sulfur or chlorine-containing insulation cottons and rubber
mats.
•
Keep the air inlet of the equipment room away from the pollution source and the sewer.
•
Place batteries separately, preferably in a separate room.