Hey Bob,
I,m having fun, so bear with me while we play, "Pick apart the other guy!" A Code Forum favorite Game Show.... [Linked Image] Kidding!

Quote
Take a ground rod and bang it into the earth, now connect a conductor to it from a 15 amp 120 volt source.

Will it trip the breaker?

If you where barefoot would you touch this ground rod?
Now is there a load between the source and the rod? The breaker just might trip with no load. Would I touch it, with load I might, wouldn't let a child do it... No load, no! It might be a 500F degrees, or 120+/- volts, or somewhere in between. (Depending on soil conditions between the rod and the rod at the transformer.)

Survey says.... Bzzzzt!

Bob, just having fun. But, I have seen a short clear on a water not bonded to a service, and several concrete floors, not bonded to the service. Because there was a rod somewhere near the trannie feeding the whole mess. Most times the resistance is too high to do it, sometimes it isn't. So, yeah I think we ground for the two reasons you mentioned , and the one I did. (Potential differance to earth)

Now the plastic thing... I still have to drive two 8'x5/8" rods or a ufer anyway! I have to do a ufer for any foundation work over 20' continous! Even after driving two rods, if the foundation work is later. But not the other way, if I have a ufer, don't need rods. Welcome to my world.

Ok, where does "ufer" come from? It is a term I have used for years and have put many in, and have no idea.... CEE = Ufer?

And while I'm at it. IMO what is "IMO"?

Mark Heller
"Well - I oughta....." -Jackie Gleason