Concrete encased electrode for residential home?

[anbm]

The NEC only requires use of a UFER in new construction if the footer construction provides for one.
You can get into a real bind if the rebar qualifies to be a UFER but no connection was made to it before pouring. You then have to chip out concrete to make an attachment point.
Some jurisdicrtions, however, require a UFER in all new construction, even if you have to lay copper wire in the footer to create one. If you skip this step in those areas you are really in trouble.

Interesting!

 

[anbm]

The resistance of a ufer ground is much much less than a ground rod. Since both are basically for lightning protection, all is needed is a ufer. If you can’t determine why the code does not require ground rods with a ufer, ask and I can explain it.

Tom, please explain.

 

[Dennis Alwon]

Tom, please explain.

I can give an example as I have a few times here on Mike Holt forum. I did a 3 point test on 1 ground rod and had 98 ohms. I added a second and got 89 ohms better but not much help. I had a ufer installed at the same site so I tested it and had 13 ohms-- It was awhile ago but I am pretty sure those number as correct or at least close.

Obviously, you want less resistance to carry any surges or lightning strikes so the ufer wins. I imagine if I added the rods that wouldn't change the 13 ohms significantly.

I would bet the ufer will always trump the rods.

 

[kwired]

NC is behind the times on this one. I wish they would require it but what they say is when the electrician gets to the job the concrete encase electrode is not available so you don't need it.

When I was running the business we always installed a concrete encase electrode unless the builder poured without calling me. I had to stay on top of the situation.

Which mas happening probably over 95% of the time and reason NEC changed to wording it now has some 10-15 years ago. They wanted to see that CEE being utilized as much as possible.

 

[kwired]

Tom, please explain.

Simple, many more times surface in contact with earth in a CEE than in a ground rod = less resistance to earth.

 

[jap]

The connection to the rebar in the footing should be an inspection department requirement prior to allowing any type of pour regardless of whether you're there or not.

Everyone needs reminded at times.

JAP>

 

[infinity]

The connection to the rebar in the footing should be an inspection department requirement prior to allowing any type of pour regardless of whether you're there or not.

Everyone needs reminded at times.

JAP>

Around here the CEE connection is inspected by the building inspector during the footing form inspection before the pour. No CEE, no pour.

I once had a job with an addition/new service and the customer asked if the new footings needed a CEE. The rebar was only 3/8" so the answer was no. Building inspector came for the form inspection and failed it for no CEE. The HO's father told him with 3/8" rebar it wasn't required but he didn't care so the old man ran to home depot and bought some bare copper and a clamp. Inspector came back later and passed it and then they poured. Turns out he bought #8 copper for a 200 amp service so I ended up just cutting it off and throwing it away.

 

[Fred B]

Most GCs I talk to around here never heard of one and never call for it to be set up before a pour is done. So this is almost never done around here. Also around here most residential electrical is done by non electrician GC, until they run into problems and can't figure it out then call with "can you fix it".

 

[kwired]

Most GCs I talk to around here never heard of one and never call for it to be set up before a pour is done. So this is almost never done around here. Also around here most residential electrical is done by non electrician GC, until they run into problems and can't figure it out then call with "can you fix it".

Who is inspecting? and are they good at enforcing other things particularly in 210.8, 210,12, 210.52.

 

[jaggedben]

Most GCs I talk to around here never heard of one and never call for it to be set up before a pour is done. So this is almost never done around here. ...

That certainly surprises me in this day and age.

 

[Abdel Rahman Mohamed]

The resistance of a ufer ground is much much less than a ground rod. Since both are basically for lightning protection, all is needed is a ufer. If you can’t determine why the code does not require ground rods with a ufer, ask and I can explain it.

Actually, in our project we use ufer grounding as a complementary, and for both grounding and lightning we use separate earth electrodes, based on your experience thats a waste of money?

 

[kwired]

Actually, in our project we use ufer grounding as a complementary, and for both grounding and lightning we use separate earth electrodes, based on your experience thats a waste of money?

The CEE will likely have less resistance to earth than your other electrodes, unless you keep adding material and re-measuring until you reach a specific resistance like they do in some instances. But for minimal NEC compliance a CEE will almost always be less resistance than two ground rods are.

 

[LarryFine]

Actually, in our project we use ufer grounding as a complementary, and for both grounding and lightning we use separate earth electrodes, based on your experience thats a waste of money?

If I;m not mistaken, all electrode systems must be interconnected.

 

[retirede]

If I;m not mistaken, all electrode systems must be interconnected.

Correct.
I think his point is that since he has a qualifying electrode, there is no need to waste money adding additional ones (ground rods) that are not already existing.

 

[Dennis Alwon]

Which mas happening probably over 95% of the time and reason NEC changed to wording it now has some 10-15 years ago. They wanted to see that CEE being utilized as much as possible.

Yep but NC didn't like it so they went back to the old wording which IMO stinks..lol

 

[kevin]

Beware of the electrical utility. Kootenai Electrical Cooperative, which services areas of northern Idaho including Coeur d'Alene, Post Falls, Rathdrum and Hayden, has this statement in their Electric Service Handbook:

KEC requires an 8 ft. copper ground rod installed even if a concrete-encased (UFER) ground is used to provide grounding.

In my conversations with electrical contractors, they are unaware of this requirement, and use only the UFER electrode (as required by the state of Idaho). Nobody that I have spoken with has been denied energization for failing to comply with the "copper ground rod" requirement.

 

[kwired]

Beware of the electrical utility. Kootenai Electrical Cooperative, which services areas of northern Idaho including Coeur d'Alene, Post Falls, Rathdrum and Hayden, has this statement in their Electric Service Handbook:

KEC requires an 8 ft. copper ground rod installed even if a concrete-encased (UFER) ground is used to provide grounding.

In my conversations with electrical contractors, they are unaware of this requirement, and use only the UFER electrode (as required by the state of Idaho). Nobody that I have spoken with has been denied energization for failing to comply with the "copper ground rod" requirement.

Someone needs to edumacate whoever is responsible for still enforcing that ground rod rule. CEE should almost always have less resistance.

 

[Rick 0920]

NC is behind the times on this one. I wish they would require it but what they say is when the electrician gets to the job the concrete encase electrode is not available so you don't need it.

When I was running the business we always installed a concrete encase electrode unless the builder poured without calling me. I had to stay on top of the situation.

In Oklahoma City, they are requiring a ufer ground in dwellings. Electricians are installing a 2 gang 1/2" rise mud ring in the garage where the rod busters have tied a vertical piece of rebar into the footer steel. The electricians use a #4 cu. and acorn clamp and put a 2 gang blank on the ring for inspection purposes. One inspector in particular requires an electrician to tie this vertical piece of rebar in place insisting that the rod busters are not qualified to do electrical work! LOL I've done several pools where the pool company has used kearneys and made the connections for the common bonding grid, passed the grounding inspection, and I simply tagged all metal equipment and terminated the ground in my pool equipment panel when I got to the job. I guess technically he was right, they are not electricians and they are doing "electrical" work. I just think he enjoys rocking the boat!

 

[kwired]

Have one foundation company (mostly just does poured walls and of course the footings they sit on) that sticks rebar out of footing but not up the wall. Electrician then has time between installation of that and before any slab floor is poured to connect a conductor to it (connection can be embedded in concrete) or is long enough to bend up and out of floor should you want access to that connection later.

 

[petersonra]

I think there is somewhat of a misunderstanding going on here. The connection to earth is not about having a connection that can take the full load current of a lightning strike

It is about trying to keep the voltage of things that are connected to earth at about the same potential as the rest of the power system in the event of some kind of surge.