I'm almost ready to install a 320 amp electrical service and would like to know what size ground rods to use. I'll be driving them into hard red clay and I would like to know the easiest , most efficient way to drive them. Also , what kind of clamps are best for attaching ground wire to rods?

Again many thanks to Mr. TK Russell for your many answers. You are an electrical godsend.

amiteman

I am not familiar with clay only, I suspect it is not a good ground plane, unless it is always wet. The minimum is one 5/8" x 8 foot copper cladded ground rod. many areas have grounding methods pre-determined and established. Check with the local inspector, or the engineering dept of the local utility.

Since any ground rod needs to be below grade, the connector needs to be direct bury rated, most we use is called an acorn clamp, looks like an acorn with a bolt out the top. This service needs a #2 ground, and if more than one rod is used, the wire needs to be continuous.

If connecting to a city water, use a 2 screw clamp for that size water pipe. Only connect to a water for a electrode no more than five feet from the point of entry.

Even if there is no city water, the metal piping in the home needs to be "bonded" to the grounding bar in the panel. Do not do any utility gas line.

If the soil is soft with no rocks, a wrench and a 5 pd sledge works, if rocky you can rent a jack hammer that has a tool to drive the rod.

Your welcome.

I use a 1 3/4 inch chipping hammer with ground rod driver attachment. With either, if it is very hard driving, have someone hold a 1/2 pipe bender at center of ground rod to keep it straight and from wobbling. It will drive better straight.