bud-- wrote:
On 3/25/2014 4:27 PM, DerbyDad03 wrote:
bud-- wrote:
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.


Thanks for the responses.

I'm still confused how the situation we're discussing matches up with this
picture. Maybe it doesn't have to?


http://www.justanswer.com/uploads/El...g_of_panel.JPG

The NEC can be much more complicated than the picture. For instance in
new construction a Ufer ground is usually installed, which replaces the
ground rods (which are a POS).


What I don't see is the connection from the ground rod to the panel. Does
the connection of the ground rod at the meter eliminate the need to connect
the panel to the ground rod?

Yes


If that's the case, then does that mean that the short ground wire to the
pipe just above the panel is redundant since a new ground wire was run from
the panel all the way back to the meter?

Yes [to the water meter]


Seems to me that the section of pipe above the panel could easily become
not grounded if a section of pipe between it and the meter was replaced
with PEX, etc. I thought that was why you had to be bonded within 5' feet
of the meter now.

It is. The connection to the water pipe near the panel is likely the
connection that was made before the service was upgraded, and was just
easily connected to the new panel. Connection at that point used to be
kosher. Them pex guys are ruining the world.



Thanks, Bud!

I will tell my neighbor that he doesn't have to worry about the service
grounding situation. The owner of the company whose worker paired up the
circuit grounds and neutrals under the same lugs is coming out next week to
fix that situation.

If I have the time, I want to be there when he does the work and have my
neighbor ask him about the service ground. I just want to hear what he has
to say.

Thanks again.