4
EMI
Electromagnetic interference (EMI) might be coupled from the source to the switch through the following
coupling mechanisms:
•
Capacitive coupling
•
Inductive coupling
•
Radiative coupling
•
Common impedance coupling
•
Conductive coupling
To prevent EMI, take the following actions:
•
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 to make sure the EMI levels do not exceed the compliant range.
•
Use electromagnetic shielding, for example, shielded interface cables, when necessary.
•
To prevent signal ports from getting damaged by over-voltage or over-current caused by lightning
strikes, only route interface cables indoors.
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.
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
2.
Select power modules and identity 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 "
."
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.
•
Leave at least 10 cm (3.94 in) of clearance at the inlet and outlet air vents.
•
The rack for the switch has a good cooling system.
