Ground Rod

[Buck Hartley, CMI]

This a re-bar ground inside. It should be copper, right? This house was built in 2008. There is a ground wire on the water line.


Thanks!

[Michael Larson]

Ufer Ground

http://www.aps.com/files/_files/pdf/ESPServices/700.pdf (see page 3)

[Buck Hartley, CMI]

Thanks! That is the first one have seen in the Kansas City area.

[Paul W. Abernathy]

Just to use this as an educational tool......which I am sure many of you are aware of but here it goes anyway.

Sometimes I get asked how come they dont see a "ground rod" in a home that has a water pipe ground?

I explain to them that ( and lets use this image as an example ) the National Electrical Code says that you must ground the electrical system and in doing so the dwelling happens to have a metal water pipe underground 10' or more in length in contact with the soil so they connect it via a listed and labeled clamp a point within 5' of the point of entry into the structure.......ok.......so like in this image why no ground rod?

Lets look at what 250.50 says :

III. Grounding Electrode System and Grounding
Electrode Conductor
250.50 Grounding Electrode System. All grounding electrodes
as described in 250.52(A)(1) through (A)(7) that are
present at each building or structure served shall be bonded
together to form the grounding electrode system. Where
none of these grounding electrodes exist, one or more of
the grounding electrodes specified in 250.52(A)(4) through
(A)[8] shall be installed and used.

Exception: Concrete-encased electrodes of existing buildings
or structures shall not be required to be part of the grounding
electrode system where the steel reinforcing bars or rods are
not accessible for use without disturbing the concrete.

Now it says we can use one of the ones present in 250.52(A)(1) - (A)(7) right.
so as we see from the original posters information that 250.52(A)(1) does exist as
that is the water pipe ground and we happen to also see 250.52(A)(3) exists also
which is the concrete encased electrode......so why no ground rod?

Thats an easy one...lets look at what 250.53(D)(2) says....

(2) Supplemental Electrode Required.

A metal underground

water pipe shall be supplemented by an additional
electrode of a type specified in 250.52(A)(2) through
(A)[8]. Where the supplemental electrode is a rod, pipe, or
plate type, it shall comply with 250.56. The supplemental
electrode shall be permitted to be bonded to the grounding
electrode conductor, the grounded service-entrance conductor,
the nonflexible grounded service raceway, or any
grounded service enclosure.
Exception: The supplemental electrode shall be permitted
to be bonded to the interior metal water piping at any
convenient point as covered in 250.52(A)(1), Exception.

OK..so you can see 250.52(A)(3) is indeed present and meets the supplilmental
requirement of 250.53(D)(2) so no ground rods would be needed.......

we can expand on this if anyone has any questions...........