Grounding

brian11973

I have been wondering what other jurisditions, other than my area, require for grounding. Here around Cleveland, Ohio, the inspectors just want a ground rod & water line. What about the other 6 or so required grounds in the Code? Also, what about putting the connection for the ground rod in the meter? It makes sense for a lighting strike. I don't have my Code book right now, there is an exception for this. Some say OK, some act like I'm an idiot AFTER trying to explain it. These are the same people who want a 1/0, etc when the Code says #6 max. What about the "ufer ground", the rebar / footer ground?

JAL

First look it up in your codebook that will tell you what the requirements are. A lot of your post has to do with the clause in the codebook referring to the AHJ. This can be the power companies, local inspectors, state inspectors, county inspectors, etc. They set their own standards sometimes and you need adhere to their requirements. Sometimes they are wrong but as long as they adhere to the NEC there is nothing that you can do except do as they say.

Speedy Petey

JAL, it sounds like Brian knows the code part but is looking for local variations.

The key issue with 250.50 is the phrase "...that are present...".

If you are under NEC 2005 a Ufer IS mandatory. A metal undergorund water pipe is also mandatory, if present. The others are not mandatory therefore installing them is optional.
Right now in my area we are not under 2005 yet so Ufers are not being enforced.

The meter pan issue is a local thing. Some POCOs want the GEC in the meter pan, some do not.
In my area they do not want any consumer grounding connections in the meter pan. All GEC's must go to the main panel/disconnect.

Some areas do not check for ground rod resistance. In almost 20 years I have never been asked for a resistance check nor have I ever even heard of one being done.
If a service has a water pipe electrode I use one supplemental rod. If there is a well with plastic feeding the house I do two.

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fridaymean

In my area the requirements are similar to Speedy's. If there is a well with plastic pipe, 2 rods 6' apart. If metal water, then ground rod and water pipe. If there is a disconnect in the meter enclosure, then a continuous wire, from the ground rod to the water pipe. It is bonded in the meter enclosure, to the service entrance conduit, in the panel and at the end of the 1/2 emt at the water pipe. The nuetral and the ground are only bonded in the meter enclosure in this case. If there is not a disconnect, then the nuetral is bonded in the panel.

Sparky Joe

We've been doing ufers on houses here since the beginning of the year. Use your table 250.66 to size your ground.
I wouldn't suggest making enemy's with the inspectors, but if they say something is wrong they have the burden to show you why, at least here they do, but I would only go that route if it came down to chipping out the foundation.
Code says minimum 6 ft apart for ground rods, but a good idea is to go at least the length of the rod apart, so they are not within each others sphere of influence.

Rounders

Here in Mass we are under the 2005 code. they are not enforcing the ufer ground. It is difficult to be on site when they pour the footings. We still use two ground rods. Havent seen a metal water feed in years.

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Brett
Boylston Electrical Company

Speedy Petey

I'm surprised about the ufer. This has become a hot issue since '05 came out for just the reason you mention.

It will be fun to try and convince the masons to leave a piece of rebar out for us. We will have to be on top of them in the early stages of the job.

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Sparky Joe

Usually you can inform the general that it is required and that it's up to them to tie wire a piece of #4 to the re-bar or else its gonna hold up the whole job while you bust out the concrete and re-pour it. The sound of slowing down the job should make them react.

sundogusa

I wouldn't trust a GC to tie a #4 to anything. They don't care as long as you get your part done. If you miss your window of opportunity, you better figure out when to get it done!

Speedy Petey

All the masons have to do is leave a piece of rebar sticking out of the concrete. The requirement is that the electrode be encased, not the connection.

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Sparky Joe

Good point

joasis

Ok, now I have seen something I need to ask my electrician about. Since his explanations are not always clear, what exactly is the point of grounding to the rebar? Is there a clear explanation in the NEC? I am not an electrician, but I try to follow everything I can.

fridaymean

The reason for grounding to a piece of rebar, is becuase of the surface area with the earth. From what I have read, whomever found all this out, figured that concrete has a high enough moisture content (below ground) to be used for grounding. Also, it is one of those instances where the plumbers, or someone else, will not come and take apart the grounding aparatus at the water meter. So, it would be "permanent." Here's something funny....In one munincipality, we have to tie hot, cold, and gas together above the water heater with a piece of #4.

JAL

The term “Ufer” grounding is named after a consultant working for the US Army during World War II. Here is the full text what he did.

Attachment 2156

brian11973

If you are under NEC 2005 a Ufer IS mandatory. A metal undergorund water pipe is also mandatory, if present. The others are not mandatory therefore installing them is optional.
Right now in my area we are not under 2005 yet so Ufers are not being enforced.

The meter pan issue is a local thing. Some POCOs want the GEC in the meter pan, some do not.
In my area they do not want any consumer grounding connections in the meter pan. All GEC's must go to the main panel/disconnect.

Some areas do not check for ground rod resistance. In almost 20 years I have never been asked for a resistance check nor have I ever even heard of one being done.
If a service has a water pipe electrode I use one supplemental rod. If there is a well with plastic feeding the house I do two.

brian11973

Now that I have screwed up on quoting some one, lets see if I can get this right.

I was looking for local variations.

A good two years ago, a friend moved from here, Cleveland, Ohio, area, to Tenn. The Rural Electric Co-Op there wanted the ground to the meter on a underground, to the overhead otherwise. The homes there had plastic water line, for the most part. I assume that he had to put in two rods. I thought it to be the oddest thing.

I had to go back & reread 250-III. It does say "all that are present". The way this reads, just one ground is OK, hence 250-53 (D) (2) " a metal underground water pipe shall be supplemented by an additional electrode........shall be permitted to be bonded to the grounding electrode conductor, the grounded service entrance conductor or any grounded service enclosure". Wouldn't the meter socket fall under this? The ground rod would only be good for a lightening strike, even two of them here. Two rods & no neutral means one whopper of a shock. The water pipe will hold down the voltage to a no noticeable shock level here. Personal experience on both.

When you stop learning, you need to stop working!

brian11973

The Ufer ground, if required, should be inspected by the "footer" inspector. The Electrical inspector would have to inform the footer inspector of the ground in the footer and / or wire. This would eliminate the problem of busting the footer up to install.

brian11973

The Code requires bonding of water lines. The Code also requires "jumping" of all insulating and / or removable fittings.These fittings are at the hot water tank( insulating to prevent corrison of the tank) and at the water meter ( removeable). Water softening equipment with unions also. The 2003 required an additional connection from the water to the gas. The 2005 Code changed this to be the connection at the furnace to suffice(14-2 home run) I have been connecting the hot / cold water / gas lines together just to make sure my a$$ is covered. The Code requires "bonding" of metal where you can contact it for the most part.

You must be using a 200 amp service. Grounding / bonding wires are based on service wire size. 100 amp require #6 ( actually #8, if not subject to damage), 200 amp,#4

joasis

So thinking about grounding and water lines, in my town, the meters are all fed by non-metalic lines now. I know on our last house, the state guy wanted 2 grounds, side by side (200 amp serv.). So if grounding to rebar is great, why not drive a rebar down through the footing and lay it over where the future serv. panel will be? Probably a dum question, but since we are in a dry climate and many times no sub-soil moisture to speak off, I don't see the "footprint" of the footing providing a great ground.

fridaymean

Joasis you should go back and read the link that some posted earlier about Mr. Ufer and his research. Around my area, Chicagoland, there is not much variation in grounding methods. There is usually city water which means metal water pipe, and then we drive a ground rod.