H3C Technologies H3C MSR 20-1X - Manual (Page 21)

14
Gas Concentration limit (mg/m 3 )
NH
3
0.05
Cl
2
0.01
Requirements on Electrostatic Discharge Prevention
Although many antistatic considerations have been given to MSR 20-1X routers, damage to circuits or
even the routers may still happen when the amount of static charges exceeds a certain limit.
In the communication network to which the routers are connected, static induction mainly comes from two
aspects: the external electric field (such as outdoor high voltage power line or thunder) and the internal
system (such as indoor environment, floor materials or the router equipment structure. Thus, the following
should be considered to safeguard the equipment against ESD.
• Make sure that the router 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 a circuit board.
• Place the removed circuit board on an antistatic workbench, with its face upwards, or put it into an
antistatic bag.
• When observing or moving the removed circuit board, it is only allowed to touch the edge of circuit
boards, instead of elements on the circuit board.
Requirements on Electromagnetic Environment
The interference sources, no matter where they come from, affect the routers in the form of capacitance
coupling, inductance coupling, radiation of electromagnetic wave, and common impedance (including
the grounding system) coupling. Therefore, the following should be considered:
• Take effective measures to prevent the power system from being interfered by the power grid system.
• Separate the return terminal of the router from the grounding device or lightning protection
grounding device of the power supply equipment and keep them as far as possible.
• Keep the router far away from radio stations, radar, and high-frequency devices working in high
current.
• Use electromagnetic shielding when necessary.
Requirements on Lightning Protection
Although many measures have been taken to protect MSR 20-1X routers from lightning, if the lightning
intensity exceeds a certain range, damage to the router may still happen. To protect the router from
lightning better, the following should be considered:
• Ensure the PGND wire of the chassis is well grounded.
• Ensure the grounding point of the AC power socket is well grounded.
• Install a lightning arrester at the input end of the power supply to enhance the lightning protection
capability of the power supply.
• Install a special lightning arrester at the input end of outdoor signal lines (for example, ISDN line,
telephone line, and E1/T1 line) to enhance the lightning protection capability.