3Com Router 6000 Family
Installation Manual
Chapter 2
Preparing for Installation
3Com Corporation
2-2
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 the equipment room
Gas Max. (mg/m3)
SO2 0.2
H2S 0.006
NH3 0.05
Cl2 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, inductance
coupling, electromagnetic wave radiation, and common impedance (including grounding
system) coupling. To prevent the interference, do the following:
z Take effective measures against interference from the power grid.
z Use an earthing system or lightning protection grounding different from that for
the power supply equipment and keep them as far as possible.
z Keep the router far away from strong power wireless launchers, radar launchers
and high frequency and high-current equipment.
z Use electromagnetic shielding when necessary.