Ufer Ground
- Thread starter herkyfred
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jimwalker
Senior Member
- Location
- TAMPA FLORIDA
Re: Ufer Ground
When i was wiring homes in Naples FL. That was the only ground they would except.Had a battle at one house cause there was none available and they refused to take 2 ground rods
When i was wiring homes in Naples FL. That was the only ground they would except.Had a battle at one house cause there was none available and they refused to take 2 ground rods
ryan_618
Senior Member
- Location
- Salt Lake City, Utah
Re: Ufer Ground
Hope this helps
Question #2: Does it require a supplement? No. You must use all available electrodes, but if the concrete encased is the only one available, then nothing else can be required, unless you have a local, legally adopted law that says otherwise.
Hope this helps
sandsnow
Senior Member
- Location
- Southern California
Re: Ufer Ground
I think a better question for formal interpretation would have been-
"Is it the intent to require a concrete encased electrode be installed whenever a building is constructed with concrete footings?"
The question asked above just asks about using the rebar already in the footing. We get a seperate piece of rebar or copper used for the UFER. The seperate rebar has been that way forever and I don't know how that came about.
Do other places use the structural rebar for the UFER
Since the footing is open for inspection of the steel, we feel that a concrete encased electrode is available and by that we require it to be installed.
btw - Ryan, do you have a link or something you could share on where formal interpretations are available
Thank You
I think a better question for formal interpretation would have been-
"Is it the intent to require a concrete encased electrode be installed whenever a building is constructed with concrete footings?"
The question asked above just asks about using the rebar already in the footing. We get a seperate piece of rebar or copper used for the UFER. The seperate rebar has been that way forever and I don't know how that came about.
Do other places use the structural rebar for the UFER
Since the footing is open for inspection of the steel, we feel that a concrete encased electrode is available and by that we require it to be installed.
btw - Ryan, do you have a link or something you could share on where formal interpretations are available
Thank You
bphgravity
Senior Member
- Location
- Florida
Re: Ufer Ground
I have read some discussions and a few IEEE reports on suplementing concrete-encased electrodes on the basis of lightning ssues and not resistance reduction.
It is believed that direct lightning strikes to concrete-encased systems are likely to damage/crack the foundation of a building, whereas adding a supplement ground rod helps to defer some of the strike intensity away from the slab.
Lightning is a wild event and is really the only strong basis for having a grounding electrode system, other than other high-voltage crossover events.
I have read some discussions and a few IEEE reports on suplementing concrete-encased electrodes on the basis of lightning ssues and not resistance reduction.
It is believed that direct lightning strikes to concrete-encased systems are likely to damage/crack the foundation of a building, whereas adding a supplement ground rod helps to defer some of the strike intensity away from the slab.
Lightning is a wild event and is really the only strong basis for having a grounding electrode system, other than other high-voltage crossover events.
ryan_618
Senior Member
- Location
- Salt Lake City, Utah
Re: Ufer Ground
Larry: I actually got that out of the handbook, section 250.50. I just happened to know that formal interpretation was right there. I think there are links on NFPA's website if you are a member...I'll look into it
Larry: I actually got that out of the handbook, section 250.50. I just happened to know that formal interpretation was right there. I think there are links on NFPA's website if you are a member...I'll look into it
sandsnow
Senior Member
- Location
- Southern California
Re: Ufer Ground
I've tried looking there, but did not see anything that jumped out at me. Also tried the search engine in the NFPA site, but no help.
Maybe you'll have better luck
I've tried looking there, but did not see anything that jumped out at me. Also tried the search engine in the NFPA site, but no help.
Maybe you'll have better luck
ryan_618
Senior Member
- Location
- Salt Lake City, Utah
Re: Ufer Ground
I did too Larry, but didn't have any luck either.
It would sure be nice if a person could get his or her hands on a list of formal interpretations. Maybe even make a book of them???
I did too Larry, but didn't have any luck either.
It would sure be nice if a person could get his or her hands on a list of formal interpretations. Maybe even make a book of them???
- Location
- Mission Viejo, CA
- Occupation
- Professional Electrical Engineer
Re: Ufer Ground
This is a list of all current Formal Interpretations that have not otherwise been "clarified" in the body of current text.
NEC Formal Interpretations
For some of you these are in the back of your NEC as well.
Of interest to this discussion as well, check this and scroll down to CMP5's "clarification." It only took 27 years
CMP Chairman Reports
[ July 08, 2004, 09:35 PM: Message edited by: rbalex ]
This is a list of all current Formal Interpretations that have not otherwise been "clarified" in the body of current text.
NEC Formal Interpretations
For some of you these are in the back of your NEC as well.
Of interest to this discussion as well, check this and scroll down to CMP5's "clarification." It only took 27 years
CMP Chairman Reports
[ July 08, 2004, 09:35 PM: Message edited by: rbalex ]
sandsnow
Senior Member
- Location
- Southern California
Re: Ufer Ground
Thanks for the links and the insight that interpretations are "deleted" after clarified in the text of the Code.
Wow only three interpretations left, I thought with such a widley discussed document there would've been more.
Thanks for the links and the insight that interpretations are "deleted" after clarified in the text of the Code.
Wow only three interpretations left, I thought with such a widley discussed document there would've been more.
- Location
- Mission Viejo, CA
- Occupation
- Professional Electrical Engineer
Re: Ufer Ground
You may find some interest in this too:
REGULATIONS GOVERNING COMMITTEE PROJECTS
Section 6 outlines the entire Formal Interpretation process.
This is why I "chuckled" at the 27 year delay:
You may find some interest in this too:
REGULATIONS GOVERNING COMMITTEE PROJECTS
Section 6 outlines the entire Formal Interpretation process.
This is why I "chuckled" at the 27 year delay:
For very practical reasons, NFPA does all it can to avoid Formal Interpretations. It would overwork many of the Technical Committees (TC) which are made up entirely of volunteers. Each CMP is considered to be a TC. Staff will usually issue an "informal interpretation" that about 90% of the time is adequate.
charlie
Senior Member
- Location
- Indianapolis
Re: Ufer Ground
I have been on CMP-10 since 1993 and have never had a formal interpretation since that time.
As far as the Ufer is concerned, I believe (I have not researched it) if reinforcing steel is used in a building footing, it will be required to be used for a grounding electrode. That will eliminate ground rods if footer steel is present.
I have been on CMP-10 since 1993 and have never had a formal interpretation since that time.
As far as the Ufer is concerned, I believe (I have not researched it) if reinforcing steel is used in a building footing, it will be required to be used for a grounding electrode. That will eliminate ground rods if footer steel is present.
- Location
- Mission Viejo, CA
- Occupation
- Professional Electrical Engineer
Re: Ufer Ground
I guess that shows how good NFPA staff is a fending them off
I don't have the figures in front of me at the moment but I believe less than a dozen NEC Formal Interpretations have been processed in the last 30 years.
I have served on four NFPA TCs and processed a few TIA's but no FI's.
I guess that shows how good NFPA staff is a fending them off
I don't have the figures in front of me at the moment but I believe less than a dozen NEC Formal Interpretations have been processed in the last 30 years.
I have served on four NFPA TCs and processed a few TIA's but no FI's.
charlie
Senior Member
- Location
- Indianapolis
Re: Ufer Ground
Sorry, in my last post the intent was for the 2005 edition of the Code.
Sorry, in my last post the intent was for the 2005 edition of the Code.
A
a.wayne3@verizon.net
Guest
Re: Ufer Ground
We use UFER alone as the ground on a service.But I see a problem with it.Since here we use slabs that are encased in plastic,where is the earth contact ??? This has come up several times with AHJ and as I write this there is supposed to be an addopted addendum being written that requires ground rod(s) in addition to the UFER.
We use UFER alone as the ground on a service.But I see a problem with it.Since here we use slabs that are encased in plastic,where is the earth contact ??? This has come up several times with AHJ and as I write this there is supposed to be an addopted addendum being written that requires ground rod(s) in addition to the UFER.
- Location
- Illinois
- Occupation
- retired electrician
Re: Ufer Ground
a.wayne,
If the concrete is not in direct contact with the earth, it is not an electrode. See 250.52(A)(3).
Don
a.wayne,
If the concrete is not in direct contact with the earth, it is not an electrode. See 250.52(A)(3).
Don
A
a.wayne3@verizon.net
Guest
Re: Ufer Ground
i agree but the building dept requires the slab to be encased in plastic sheeting.That is my point how can it be earth grounded without contact ??? As long as there is a 20 ft. piece of # 5 rebar stubbed out it passes.
i agree but the building dept requires the slab to be encased in plastic sheeting.That is my point how can it be earth grounded without contact ??? As long as there is a 20 ft. piece of # 5 rebar stubbed out it passes.
wirebender
Senior Member
- Location
- North Central Texas
Re: Ufer Ground
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