ufer ground

[elecmen]

Can you use the 1/2" rebar in a 6" thick slab where a manufactured home is going on ? There is poly plastic under the rebar. The rebar is tied together and over 20' long. Want to use it as the grounding electrode.

 

[infinity]

Nope. For one thing the poly would negate any of the concrete actually being in contact with the earth.

 

[ActionDave]

It doesn't sound like you can.

(3) Concrete-Encased Electrode.

Metallic components shall be encased by at least 50 mm
(2 in.) of concrete and shall be located horizontally within
that portion of a concrete foundation or footing that is in di-
rect contact with the earth or within vertical foundations or
structural components or members that are in direct contact
with the earth. If multiple concrete-encased electrodes are
present at a building or structure, it shall be permissible to
bond only one into the grounding electrode system.

Informational Note: Concrete installed with insulation,
vapor barriers, films or similar items separating the concrete
from the earth is not considered to be in ?direct contact?
with the earth.

 

[Sierrasparky]

It doesn't sound like you can.

(3) Concrete-Encased Electrode.

Metallic components shall be encased by at least 50 mm
(2 in.) of concrete and shall be located horizontally within
that portion of a concrete foundation or footing that is in di-
rect contact with the earth or within vertical foundations or
structural components or members that are in direct contact
with the earth. If multiple concrete-encased electrodes are
present at a building or structure, it shall be permissible to
bond only one into the grounding electrode system.

Informational Note: Concrete installed with insulation,
vapor barriers, films or similar items separating the concrete
from the earth is not considered to be in ?direct contact?
with the earth.

Thanks for the informational note. Good to know.

 

[nhee2]

Probably a dumb question -

In this installation, then, is the rebar considered a grounding electrode that is present and must be bonded together with other electrodes per 250.50, or is it not considered an electrode, so that bonding is not required?

 

[jumper]

Probably a dumb question -

In this installation, then, is the rebar considered a grounding electrode that is present and must be bonded together with other electrodes per 250.50, or is it not considered an electrode, so that bonding is not required?

The rebar in this slab is not a GEC and does not require any bonding.

 

[infinity]

To touch on Jumper's post, if you look at Dave's post you'll see that a slab even with rebar doesn't qualify as an grounding electrode because it's not a "portion of a concrete foundation or footing".

 

[nhee2]

Thanks. I agree. And there is no requirement to create a CEE provided one of the other grounding electrode types is available.