What actually counts as a good installation?

[Arthur]

Two 8-foot ground rods, minimum 6 feet apart, driven to full depth, connected with a 6 AWG or better conductor to your panel ground that's the basic NEC requirement and it sounds simple until you're staring at a caliche layer 18 inches down or a rock shelf that won't let you get more than 4 feet in. The code has provisions for this , you can angle them, use chemical ground rods or in extreme cases document the soil resistance. What doesn't work is a short rod not driven fully, a corroded clamp connection or a wire that runs a longer path than necessary with splices in it. The ground is only as good as its continuity back to the source.

 

[Alan]

Yeah, that’s the part that gets missed most often. People focus on driving rods, but corrosion, loose clamps and sloppy splices are usually what turn a code compliant setup into a weak ground in real conditions.

 

[PGB1]

The code has provisions for this , you can angle them, use chemical ground rods or in extreme cases document the soil resistance.

Often an easy one, allowed by NFPA 70 at 250.53 is a plate electrode. Two square feet (example 1.42' x 1.42') of 0.06" thick non-ferrous metal or 1/4" steel is approved. Thirty inch or greater depth. You can buy them pre-made with a clamp installed- even in a 2-ft2 circle shape.

A rod laid horizontally in a trench 30" below grade is acceptable also.

Grounding Ring is another.

And, if a construction site any you get there before the concrete is installed, a Concrete Encased Electrode might be easiest.

Just some options to share. (Have used them all and have also used built, saline electrodes)

Paul