ECN Forum Forums Code Related Discussion NEC & other Code issues Ground Rod Woes Revisited...

Right on Don. 5/8" x 8' contact area simply can't compete...

interesting obsvervation E~Scott, i never really considered this ( so thank you~!)......
again appliable to what seems the least efficent

Well, the last ground rod I sank took all of two minutes and went in with nothing more than a 2 lb. ball-pein hammer. Still, that was only a 4 ft. rod and the soil here is sandy and largely free of rocks and other impediments!

Virgil,
Have a look here where we discussed testing ground rod resistance using the traditional three-electrode method.

Virgil,

If you do an Encased Electrode [Ufer], here's some specs:

<OL TYPE=1>

[*]At least 20 feet of Encased Conductor,

[*]Depth of at least 24 inches,

[*]Largest Conductor size is 4 AWG cu I believe - verify in Article 250.
</OL>

Suspend the bare Conductor so it will be in the center of the Concrete. This can be done several ways, but one of the simplest is to pour a "Bottom Layer" of Concrete first, place the Conductor on top of it, then pour the "Top Layer" of Concrete.

Good luck!

Scott S.E.T.

I am not sure yet sparky66, Im still waiting for the snail mail from SBCCI
yeah, the megger I got is used for checking old feeders etc. mostly underground feeders because of the corrosive soil here by the coast. most of them I check fail.. I was fed up with that last barn I worked on and a megger would have saved me lots-o-time. at least I made enough on that job to by a megger ...
On second thought , maybe I will suggest new underground feeders/services BEFORE I troubleshoot

Here are some pictures of a Uffer I recently installed. It has to be near the bottom exterior of the footing. The pictures were for the AHJ incase he didn't show up for the 8:00AM concrete pour. The pour was on a Monday morning and I discussed getting pictures for him the previous week. The job is in a rather shady industrial area and I convinced them that if I installed the copper the previous week for inspection it would disappear over the weekend. Now that is in and we are off site I am expecting to come back and see the tails that go to the gear cut off at the concrete. Maybe I will get lucky.
You probably can't see in the picture but the copper is suspended off the rebar. I got in this habit because of a rebar inspector a while back. He did not like to see our 4/0 copper running with and tied to the rebar. He claimed it displaced concrete. So what I did was hung it off the top straps with tie wire then tied it down to the lower straps to keep it from floating. Keeps everyone happy. Even doing it this way the whole thing takes about 20 minutes to install.

Nick — Aren’t pictures you don’t have to get from the drugstore wonderful? And this crazy internet.

Have any of you had any success getting the rebar stubbed up at the location of your service disconnecting means? Since the rebar itself is acceptable as an electrode why not use it?

On one job I supplied a twenty foot long, half inch, galvanized, rebar and the concrete guys put the 90 and the kick in it and tied it to the top of their stirrups. After the connector sleeve was in place I painted the whole thing with the same black protective coating that is used on rigid conduit threads. I am assuming that it will outlast the building.
--
Tom

In my area (Northern CA) the foundation contractor usually provides the UFER ground many times without asking them to. They tie 2 additional 20' pieces of rebar (1 in each direction) to their lowest bar in the footing and leave them sticking up above the foundation about 18" near the service panel location.

Curt