How far does my grounding wire wander?

Question

I don't know if my question is even answerable, but I'd appreciate any insight.

My home was built pre-1960. There is a grounding wire that goes into the ground (obviously) around 6 inches from the house outer walls, just under the main electrical box. I need to install a fence which terminates at that corner of the house. This is a "no-dig" fence, so I drive in metal stakes with a sledgehammer and insert posts within.

My question is, how far would this grounding wire wander? If I pound stakes at least a foot from where it enters the ground, am I OK? Or should I leave more of a buffer?

Also, what if the stake ends up touching the grounding wire somewhere underground, would anyone touching the metal fence get electrocuted (not totally sure how grounding works...))? The stakes go 2-ft deep.

Answer 1

There's no telling in any specific case.

In most cases it's not going to be buried very deep, so you could excavate the grounding conductor (carefully, by hand) to verify its path. Most likely it runs more or less straight from point to point, so you should not have to excavate the whole thing to determine if it is likely to intersect your fencepost position.

Typically it's going to at least one, more often two driven ground rods, rarely to some other electrode type such as a plate or ground ring. The first one is usually very close to where it goes into the ground at the house. Minimum spacing on the pair of rods is 6 feet, a better worker will use a bit more wire to space them further apart (like 8-10 feet.) My own runs all the way to the well casing, (more than 100 feet) as that 100 feet of 6" steel is the best ground rod I have available.

If you touch it with your fencepost, nothing exciting happens. If you cut through it with your fencepost, there's some potential for unpleasant results. I'd suggest making the effort to avoid that.