H3C Technologies H3C SecPath M9000 Series - Manual (Page 12)

4
EMI
Electromagnetic interference (EMI) might be coupled from the source to the gateway through the
following coupling mechanisms:
• Capacitive coupling
• Inductive coupling
• Radiative coupling
• Common impedance coupling
• Conductive coupling
To prevent EMI, take the following actions:
• Filter interference from the power grid.
• Keep the gateway grounding facilities away from grounding and lightning protection facilities of
other devices.
• Keep the gateway far away from radio transmitting stations, radar stations, and high-frequency
devices to make sure the EMI levels do not exceed the compliant range.
• Use electromagnetic shielding, for example, shielded interface cables, when necessary.
Grounding
Using a good grounding system to protect your gateway against lightning shocks, interferences, and
ESD is essential to the operating reliability of your gateway.
Make sure the resistance between the chassis and the ground is less than 1 ohm. For more information
about grounding the gateway, see "Installing the gateway."
Power
Perform the following tasks to meet the power requirements:
1. Calculate the system power consumption.
The system power consumption varies by card type and density. For more information about
system power consumption calculation, see "Appendix A Chassis views and technical
specifications."
2. Select power modules and identify the number of power modules.
The total maximum output power of all power modules must be higher than the system power
consumption. For more information about available power modules, see "Appendix B FRUs and
compatibility matrixes."
3. Verify that the power system at the installation site meets the requirements of the power modules,
including the input method and rated input voltage.
Cooling
Plan the installation site for adequate ventilation.
• The installation site has a good cooling system.
• The rack for the gateway has a good cooling system.