H3C AR 46 Series Routers Installation Manual
Chapter 2 Preparing for Installation
2-2
Table 2-2
Limits on the dust particles in the equipment room
Mechanical active
material
Unit
Content
Dust particle
particle/m³
≤
3 x 10
4
(No visible dust on desk in three days)
Note: Dust particles’ diameter
≥
5µm
Besides, the equipment room should meet the rigorous limits on salt, acid and sulfide to
eliminate corrosion and premature aging of some parts, as shown in the following table.
Table 2-3
Harmful gas limits in an equipment room
Gas
Max. (mg/m3)
SO
2
0.2
H
2
S 0.006
NH
3
0.05
Cl
2
0.01
2.1.3 ESD Prevention
By design, the router is ESD preventative; but excessive buildup of static electricity can
still damage the card circuitry and even the entire device.
On the communication network connected to the router, static electricity is primarily
introduced from the outside electrical fields, such as the outdoor high-voltage power
cabling and lightning, and from the inside system, such as indoor environment, floor
material and the equipment frame. To avoid damage, ensure that:
z
The equipment is well connected to earth.
z
The equipment room is dust-proof.
z
Maintain adequate temperature and humidity.
z
Wear an ESD-preventive wrist strap and clothes when contacting the circuit board.
z
Place the removed circuit board upward on the ESD-preventive workbench, or into
a static shielded bag.
z
Hold the circuit board by its edge when observing or moving it, avoiding direct
contact with the elements on it.
2.1.4 Electromagnetic Compatibility
All interference sources, from the outside or from the inside of the router/application
system, adversely affect the router in the conduction patterns of capacitance coupling,