H3C Technologies H3C S12500-X Series Switches - Manual (Page 12)

4
Gas Max. (mg/m 3 )
Cl
2
0.01
EMI
All electromagnetic interference (EMI) sources, from outside or inside of the switch and application
system, adversely affect the switch in the following ways:
• A conduction pattern of capacitance coupling.
• Inductance coupling.
• Electromagnetic wave radiation.
• Common impedance (including the grounding system) coupling.
To prevent EMI, perform the following tasks:
• If AC power is used, use a single-phase three-wire power receptacle with protection earth (PE) to
filter interference from the power grid.
• Keep the switch far away from radio transmitting stations, radar stations, and high-frequency
devices.
• Use electromagnetic shielding, for example, shielded interface cables, when necessary.
Grounding
Using a good grounding system to protect your switch against lightning shocks, interferences, and ESD
is essential to the operating reliability of your switch.
Make sure the resistance between the chassis and the ground is less than 1 ohm.
For more information about grounding the switch, see "Installing the switch."
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. 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. For more information about power module
specifications, see "Appendix B FRUs and compatibility matrixes."