Ground rod to exterior subpanel

[zimmy1948]

I am running a subpanel outside and wondering if a ground rod in addition the ground to my interior panel is necessary.
Is it a good idea? All my interior wiring passes inspection.

 

[Don Farrell]

If the secondary panelboard is not in the same building as the original panelboard, you must run a four wire cable or four conductors to supply the secondary panelboard. Also, you must have a separate grounding system (one or two ground rods) at the secondary site. You Cannot connect the ground from the main panelboard to the ground at the secondary panelboard.

Contrary to popular thought, the grounding system is to protect against high voltage spikes and lightening, not to ground the equipment to earth.