Requirements On Electrostatic Discharge Prevention; Requirements On Electromagnetic Environments - 3Com MSR 50-40 ROUTER. Installation Manual

Besides the dust specifications, the equipment room of the Router should also meet the rigorous
requirements for the content of salt, acid and sulfide. These harmful gases could accelerate the metal
erosion and aging process of some parts. The specific limits of these harmful gases as SO
NH and CI are given in the following table.
3 2
Table 2-3 Limitation on harmful gases in equipment room
SO
2
H S
2
NH
3
Cl
2

Requirements on Electrostatic Discharge Prevention

Although many antistatic considerations have been given to MSR 50 Series, damage to the router's
circuit or even the whole equipment may still happen when the static electricity exceeds the tolerance
threshold.
In the communication network to which the routers are connected, static induction mainly comes from
two aspects: external electric fields such as outdoor high voltage power line or thunder and internal
environment like flooring materials or the whole equipment structure. Thus, the following should be
considered to safeguard the equipment against the ESD.
Make sure that the equipment and the floor are well grounded.
The equipment room is dust-proof.
Maintain an appropriate humidity and temperature.
Wear an ESD-preventive wrist strap and uniform when contacting the circuit board.
Place the removed circuit board on the antistatic workbench, with its face upward, or put it into the
static shielding bag.
When observing or moving the removed circuit board, please touch the edge of the circuit board,
and avoid contacting the devices on it.

Requirements on Electromagnetic Environments

The interference sources, no matter where they come from, affect the routers with capacitance coupling,
inductance coupling, radiation of electromagnetic wave, common impedance (including the grounding
system) or conducting line (power line, signal line and transmission line etc.). So the following should be
considered:
Take effective measures to prevent the power system from being interfered with by the power grid
system.
Use an earthing system or lightning protection grounding different from that for the power supply
equipment and keep them as far as possible.
Keep the router far away from the radio launcher, radar launcher, and high-frequency devices
working in high current.
Use electromagnetic shielding when necessary.
Gas
2-2
Max. (mg/m
0.2
0.006
0.05
0.01
, H S, NO ,
2 2 2
3
)