ECN Forum Forums Code Related Discussion NEC & other Code issues Additional Ground Rod

Bob:
Good evening (long day for me).
What you have in your drawing is a 'no question' job, and there is no issue.
The way I read (past tense) the original post.

...Lets say you have a #4 to a water pipe and then a #6 from there to two rods. You can't run a #4 GEC from the service to the rod because the bonding wire to the pipe is too small. Running a #4 GEC to the water pipe would be OK. Running a #4 GEC to the first rod would be OK as long as a #4 connects the first rod to the pipe. Even if there was a #6 from the first rod to the second this would still be OK."

I read that as going from a resi service panel to the water pipe, and from the water pipe to the rods....just don't sit right...never have seen anyone go that route, even the 'lectrician named "self" & his buddy "homeowner". The route everyone around here takes is panel to water pipe, panel to rods; excluding the McMansions with ufers.

John

Gentlemen- as usual these threads seem to drift. That's not a bad thing because it brings in good information. BUT- The orginal post only talked about rods. Nothing was mentioned about steel or water . And for my money- two rods with a jumper (#6 awg cu) between them would constitute a grounding electrode system satisfying the code minumum requirement unless, there were other electrodes present. That said- a single Maximum size 6 AWG cu run to either rod gets the job done. The size of the service is a moot point.

It might not sit right with you Hotline1, but it is perfectly allowed by the NEC.

Study the path the GECs take in the picture iwire posted. A lot of electricians with way more experience than me are shocked by it. The are many tales of required paths GECs are to take, yet they are not based on the code.

[This message has been edited by dmattox (edited 09-21-2005).]

"A lot of electricians with way more experience than me are shocked by it."

No pun intended, I'll bet.

Hi John, I am not following you on this.

As log as one keeps the wire size correct for the route they take all is good.

Either of the following will meet code.

Panel > 4 AWG > Water Pipe > 6 AWG > Ground rod.

Or

Panel > 4 AWG > Ground rod > 4 AWG > Water Pipe.

They sure do but I did not see the actual subject drifting to much here.


I agree.

Greg


I think that is an excellent question.

Here is my answer.

I do not consider the cement itself to be an electrode. Think of what the NEC calls it.

"Concrete-Encased Electrode"

That being the case you would have to hook into the electrode itself not just another rebar.

IMO the rebar would have to be tied together continuously for that 300' in order to do what you ask.

Personally I would not be comfortable doing it that way but IMO the NEC allows it.

Bob-

Just out of curiosity, if you were able to verify that the rebar was indeed tied together for the entire 300', would you still be uncomfortable with the installation? Personally, I'd be quite comfortable with it. The key is knowing for sure that the bar is tied together. As far as the length is concerned, the electrode needs to be at least 20' but can (and most times is) longer than that.

Bear in mind the NEC says a Ufer is only worth a #4 cu GEC. The connection between rusty rebar is only being lapped and somewhat loosely tied with rusty wire. Still OK with it?

I was hoping someone might have heard of a real test to see how much the concrete adds to the connection.
I think of this like the dirt between those rods within the "well of influence".

Guys:
I'nm not trying to start a war..the point that I'm saying is that I have not seen anyone run a EGC to the water, and from the water to the rods. Nor did I say it may be a violation.


John