The infamous and elusive UFER

I'm still back on which codes require the construction of a CEE. Do some state building codes or electrical code amendments? Not the NEC AFAICT.

Art 250.50 says "All grounding electrodes as described in 250.52(A)(1) through (A)(7) that are present [...] If none of these grounding electrodes exist, one or more of the grounding electrodes specified in 250.52(A)(4) through (A)(8) shall be installed and used." CEEs are (A)(3). It's a long stretch to argue that none are present when the structure hasn't been built, but even then making a CEE isn't needed.
 
Are there any "Good Engineering Practices" papers for installing UFER systems?
Or is it up to the concrete contractor to do it correctly?
 
zbang said:
I'm still back on which codes require the construction of a CEE. Do some state building codes or electrical code amendments? Not the NEC AFAICT.

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I don't think any national or international code requires a CEE *per se*, but many codes require concrete to be reenforced and thus effectively require creating a CEE if doing a concrete foundation. Or at least they did before the vapor barrier requirements got put in. But the enforcement of having the CEE and GEC installed before pouring is local rules or enforcement decisions.

You can also always build a structure on something else like steel pilings, which is one reason a CEE won't ever be universally required.
 
Dennis Alwon said:
NC has an amendment that basically went back to the old code wording so that a concrete encase electrode is not required.

The code states All grounding electrodes as described in 250.52(A)(1) through (A)(7) that are present at each building or structure served shall be bonded together to form the grounding electrode system.

NC took out present and put in the word "available" which is still questionable but they have made it clear that it isn't required
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NEC changed the wording as they discovered there wasn't really many CEE's in use even though most footings qualified.

That said NEC kind has always been full of dirt worshippers and as long as you are served by a utility that has grounding electrodes at nearly every structure of their distribution system electrodes at the customer buildings/structures likely isn't really all that critical yet doesn't hurt to have it either.
 
kwired said:
NEC changed the wording as they discovered there wasn't really many CEE's in use even though most footings qualified.

That said NEC kind has always been full of dirt worshippers and as long as you are served by a utility that has grounding electrodes at nearly every structure of their distribution system electrodes at the customer buildings/structures likely isn't really all that critical yet doesn't hurt to have it either.
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Well, I did an experiment on a new house that we were doing. I installed a concrete encase electrode and then drove ground rods and did a 3 point test.
I had 98 ohms with one rod and 89 ohms with 2 rods. The concrete encase electrode had 13 ohms. I am going from memory but I am sure these numbers are close.

That being said which would you prefer at your home?
 
zbang said:
I'm still back on which codes require the construction of a CEE. Do some state building codes or electrical code amendments? Not the NEC AFAICT.

Art 250.50 says "All grounding electrodes as described in 250.52(A)(1) through (A)(7) that are present [...] If none of these grounding electrodes exist, one or more of the grounding electrodes specified in 250.52(A)(4) through (A)(8) shall be installed and used." CEEs are (A)(3). It's a long stretch to argue that none are present when the structure hasn't been built, but even then making a CEE isn't needed.
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NEC simply says if it is present you must use it, exception for existing structures that may have a qualifying CEE but is not readily accessible.

The rules once said if available. They figured out that the footings were often done long before the electricians were ever on site and qualifying CEE's were there but not being used-they were not available when the electricians arrived.

They changed wording to say "where present" and only added the exception for existing structures. Which kind of means new building with qualifying electrode needs to use that electrode and is much easier to connect if you are there at time footing is being constructed, or at least if footing contractor helps out in some way with how they build it.
 
Dennis Alwon said:
Well, I did an experiment on a new house that we were doing. I installed a concrete encase electrode and then drove ground rods and did a 3 point test.
I had 98 ohms with one rod and 89 ohms with 2 rods. The concrete encase electrode had 13 ohms. I am going from memory but I am sure these numbers are close.

That being said which would you prefer at your home?
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Net impedance during a lightning incident is really what matters. Either one could be better once you factor in other conditions that will impact that impedance with high voltage high frequency lightning current. If you have a fairly direct strike, you have good chance of damages whether you have a proper electrode or not. If there is a strike down the road- you get a lesser surge and the bulk of it is dissipated through the MGN network. Still doesn't hurt to have an electrode at your service but it may or may not really help.

That said I'd still connect to a CEE for my own home. This is not as big of a joke as AFCI's are, nor some the new GFCI requirements added in the past 10-12 years.
 
I put one in my home when I built it in the early 90’s. CEE’s were mainly used in commercial and industrial at that time. Everyone was still pounding ground rods for residential at that time. But then I also have a single phase QOD panelboard in my house too.
 
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