Cisco Systems Cisco 12816 Manuale Utente

To ensure a satisfactory supplemental ground connection to the router, use the 
following parts:

These parts are not available from Cisco, but are available from commercial 
vendors.

Two grounding lugs, which have two M6 bolt holes with 0.625 to 0.75-inch 
(15.86 to 19.05-mm) spacing between them, and a wire receptacle large 
enough to accept a 6-AWG or larger, multistrand copper wire. This lug is 
similar to those used for the DC-input power supply leads (see 

).

Two M6 hex-head nuts and locking washers (nickel-plated brass is ideal).

Two grounding wires. Although we recommend at least 6-AWG multistrand 
copper wire, the wire diameter and length depend on your router location and 
site environment.

When planning the location of the router, consider distance limitations for 
signaling, electromagnetic interference (EMI), and connector compatibility. If the 
wiring is run for any significant distance in an electromagnetic field, interference 
can occur between the field and the signals on the wires. Poor wiring can cause:

Radio interference emanating from the wires.

Strong EMI, especially when caused by lightning or radio transmitters. EMI 
can destroy the signal drivers and receivers in the router, and can even create 
an electrical hazard by conducting power surges through lines and into 
equipment.

To predict and remedy strong EMI, you may need to consult with experts 
in radio frequency interference (RFI).