Re: Well casing as Grounding Electrode
I'd say it's in the eye of the beholder. In our world, the beholder is the inspector.
Just to be clear, I think it's cool you used it. I would take issue if you hadn't, and an inspector claimed the well was "present at the structure."
By that reasoning, if a city water main was metallic, and the run between the street and the house were PVC, then you be required to trench out to the street to make use of the "present" electrode, despite the common understanding that it is not present at the structure.
George, I still don't see where the grounding electrode is required to be "Present at the structure". The only place that I see that phrase used is in 520.50. That just says all electrodes present at the structure must be bonded together.
That's one half of the requirement.
So think of this as a machine would:
250.50 Grounding Electrode System. All grounding electrodes as described in 250.52(A)(1) through (A)(6) that are present at each building or structure served shall be bonded together to form the grounding electrode system....
You have a black and white, true or false situation presented by this section.
Do you have grounding electrodes present at the structure: No.
Since the answer is no, the last sentence kicks into effect:
...Where none of these electrodes exist, one or more of the electrodes specified in 250.52(A)(4) through (A)(7) shall be installed and used.
There is nothing in the middle--there's no "close" or "far" electrodes. There either "are" electrodes, or "are no" electrodes.
Once requirements in the NEC are satisfied, you can venture beyond them. But the requirements, the shalls and shall nots, must be followed.
Look at it this way. Let's say you decided you wanted to GFI protect a whole house. You go through, putting GFI's in everywhere, content that you were exceeding code and creating a safer home. But then you run out when you get to the garage.
Does the massively GFI protected house compensate for the lack of GFI protection in the garage? No.
This grounding system is similar, IMO.
