Grounding

[The Learner]

Hello ya’ll
If I drove a ground through a dug out footing 5’ into the earth (the footing is 6’ deep and 40’ long) and ran a wire out of the footing and then they poured it in concrete is that an adequate grounding point? Will I get less that 25ohms to ground with a meter?

Paul

 

[infinity]

So you're installing an 8' ground rod?

 

[Dennis Alwon]

If you are trying to get a concrete encased electrode then the wire should be near the bottom of the footer.

Also 25 ohms is not required....

 

[The Learner]

So you're installing an 8' ground rod?

The ground ride is 6’ in the dirt in the bottom of the footing and the top of the ground rod will be in the pour.

If you are trying to get a concrete encased electrode then the wire should be near the bottom of the footer.

Also 25 ohms is not required....

The 25ohms is in the spec so required from this perspective

I would thinkthe concrete would be better than the dirt

 

[infinity]

Is the footing really 6' deep? If so with a footing that size you almost certainly need to use a CEE and not a ground rod. If you use a rod it needs to be 8' in the earth.

 

[Dennis Alwon]

A few questions.... Is there steel- rebar in the footing? If so attach to that with an acorn clamp approved for direct burial(DB). If not then lay 20' #4 in the footing and leave enough to reach your main disconnect or meter.

Haha, that is only one question....

 

[The Learner]

A few questions.... Is there steel- rebar in the footing? If so attach to that with an acorn clamp approved for direct burial(DB). If not then lay 20' #4 in the footing and leave enough to reach your main disconnect or meter.

Haha, that is only one question....

Specs are calling for a rod. Thanks ya’ll. I’ll see what I get on what I have. Or I’ll drive a rod 10’ away and do it there

 

[infinity]

Specs are calling for a rod. Thanks ya’ll. I’ll see what I get on what I have. Or I’ll drive a rod 10’ away and do it there

You didn't answer the question about the rebar. If there is 20' or more of 1/2" or larger rebar then you must install a CEE.

 

[Dennis Alwon]

Specs are calling for a rod. Thanks ya’ll. I’ll see what I get on what I have. Or I’ll drive a rod 10’ away and do it there

I seriously doubt you will get 25 ohms with a rod. A concrete encased electrode will probably get you below 25 ohms.