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bud--

On 3/25/2014 3:09 PM, wrote:
On Tue, 25 Mar 2014 12:35:59 -0700 (PDT), trader_4

So you have one grounding electrode, ie the water service pipe
that comes directly into the panel.
According to Bud, the supplemental electrode(s) can be at the meter
and it sounds like that's where they are. The only part I'm confused
about is that you appear to have just two hots and a neutral coming into
the panel from the meter. So the neutral which is a current carrying
conductor would be what ties the grounding system together, ie it
connects the water pipe ground at the panel to the supplemental grounds
across a distance of 5ft, 10ft? whatever. Is that OK with code? Seems questionable to me. Bud?

In this case the most useful ground is the water pipe, which is
connected at the panel. Other comments below.

You can attach the grounding electrode conductor any place between the
service point to the service disconnect enclosure. Connecting in the
meter base is pretty common around here.

In this system there are 2 points of attachment. I don't think that is
OK in general, but in this case it is OK to attach the "supplemental"
ground rods at a separate place (the meter, if that is what is attached
there).

You can have all the grounding electrodes (GEC) attached at the meter
(as at g's location). And the N-G bond ("main bonding jumper") is at the
service disconnect. That is code compliant, but seems a bit odd to me.
Like ferinstance if you had a neutral connection failure on the neutral
from the meter to the disconnect it wouldn't be too healthy. Comment?

(I have never seen one done that way, but basements are very common here.)

Minneapolis still has a municipal metal water system. If the GEC
(including water pipe) is connected at the panel, and the service
neutral opens at any point, the neutral current will be to the water
pipe, to other houses, and back to the service neutral. The neutral
voltage shouldn't float much.