How far apart do ground rods need to be?
Consequently, how many ground rods are required?
Code requires one ground rod and you prove 25 ohms, or two ground rods and you donâ€™t have to prove it. No. The requirement is 2 rods spaced at least six feet apart unless you can prove one rod will turn less than 25 ohms resistance. That is all the requirement is.
Furthermore, what minimum distance should be there between two earthing electrodes? Distance between two earthing pit is 2 X Length of earthing electrode. If ground resistance is less than plate earthing (if hard rock) than Pipe earthing shall be used. Resistance between two earthing pit is negligible. Earthing of lighting protection should not mix with power system earthing.
Similarly, it is asked, what is the minimum depth for a ground rod?
Do you need 2 grounding rods?
Ground rod spacing. Suppose you drive the first ground rod for a system. If it has a ground resistance of 25 ohms or more, 250.56 of the 2005 NEC requires you to drive a second rod. They simply plan on driving two rods because doing so will meet the requirements of 250.56, regardless of actual ground resistance.