1-4
Table1-4 Corrosive gas concentration limits
Gas
Average concentration (mg/m
3
)
Maximum concentration (mg/m
3
)
SO
2
0.3
1.0
H
2
S
0.1
0.5
Cl
2
0.1
0.3
HCI
0.1
0.5
HF
0.01
0.03
NH
3
1.0
3.0
O
3
0.05
0.1
NO
X
0.5
1.0
CAUTION:
As a best practice, control the corrosive gas concentrations in the equipment room at their average
values. Make sure the corrosive gas concentrations do not exceed 30 minutes per day at their
maximum values.
To control corrosive gases, use the following guidelines:
•
As a best practice, do not build the equipment room in a place with a high concentration of
corrosive gases.
•
Make sure the equipment room is not connected to sewer, vertical shaft, or septic tank pipelines
and keep it far away from these pipelines. The air inlet of the equipment room must be away
from such pollution sources.
•
Use environmentally friendly materials to decorate the equipment room. Avoid using organic
materials that contains harmful gases, such as sulfur or chlorine-containing insulation cottons,
rubber mats, sound-proof cottons, and avoid using plasterboards with high sulfur concentration.
•
Place fuel (diesel or gasoline) engines separately. Do not place them in the same equipment
room with the device. Make sure the exhausted air of the engines will not flow into the
equipment room or towards the air inlet of the air conditioners.
•
Place batteries separately. Do not place them in the same room with the device.
•
Employ a professional company to monitor and control corrosive gases in the equipment room
regularly.
Examining the installation site
Before you install the switch, verify that the installation site meets the installation requirements. The
switch can operate correctly in an A1 or A2 installation site. Availability issues might occur if you
install the switch in an A3, B1, B2, or C installation site.
Table1-5 Installation sites
Category
Definition
Example
A1: indoor controlled
environment
•
Indoor environments where
temperature and humidity are
controlled.
•
Completely enclosed or shielded
indoor environments.
Central equipment rooms, IDC
equipment rooms, mobile cabins
with air conditioners, outdoor air
conditioner cabinets, and heat
exchanger cabinets.
A2: indoor partially
controlled
•
Indoor environments where
temperature and humidity are partially
Simple equipment rooms, ordinary
houses, garages, corridors, and