Ufer smaller than #4 copper

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zcanyonboltz

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250.52 (A) (3) (2) says- bare copper not smaller than #4. 250.102 (C) (1) allows smaller wire depending on the size of ungrounded conductors. The feeders from power company on most my jobs are 1/0 or 2/0 aluminum underground feeds. I have been running #6 copper to cold water and ufer and have had no problems with several inspectors. Another crew came out and ran #4 copper to ufer and said #6 is a code violation. What am I missing is running #6 to a ufer a violation of 2014 NEC? The shop sends #6 for 150A service and #4 for 200A service. Thanks.
 
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Code says that the GEC to a UFER need not be larger than #4 regardless of what other formulas may call for.
There is no requirement to use #4, but using #4 avoids both explanations to the inspector and future expansion issues.
 
GoldDigger said:
Code says that the GEC to a UFER need not be larger than #4 regardless of what other formulas may call for.
There is no requirement to use #4, but using #4 avoids both explanations to the inspector and future expansion issues.
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What explanations would be avoided if #6 is legal? With underground feeders and overhead feeder I have done service changes but we never up sized the service drop or laterals for expansion to a larger service. We have upsized the service entrance conductors.

250.52 (A) (3) (2) says "bare copper conductor not smaller than 4 AWG."
 
If your embedding the copper conductor in the footing to create a CEE then it needs to be #4 or larger. You can connect a smaller GEC to that #4 if the smaller GEC is all that you need. Also you could use a smaller than #4 GEC to a CEE made by attaching to the 20' of #4 or larger rebar if say only a #6 or #8 is required due to the size of the SEC's.
 
I know its rebar connected by the "usual tie wires." We have been running number 6 and this must be okay with AHJ or the inspectors do not know, two of my inspectors are former JW electricians. I just don't see why a lot of other licensed electricians I talk with think the GEC is sized based on main breaker size and that's why the shop sends #4 for 200A and #6 for 150A I'm wondering why shop does this several companies I've worked for do the same thing.
 
zcanyonboltz said:
What explanations would be avoided if #6 is legal? With underground feeders and overhead feeder I have done service changes but we never up sized the service drop or laterals for expansion to a larger service. We have upsized the service entrance conductors.

250.52 (A) (3) (2) says "bare copper conductor not smaller than 4 AWG."
Click to expand...
Grounding electrode conductors are to be sized in accordance with the size of the largest ungrounded service entrance conductors, or equivalent of parallel conductors. Look at the headings in table 250.66 - it says this right there.

250.52(A)(3)(2) is telling you if you use a piece of copper conductor as the electrode in the concrete it must not be smaller then 4 AWG.
250.66(B) tells you the GEC that solely connects to a CEE need not be larger then 4AWG. Most run 4 AWG anyway even if they could run smaller - that way if the service size ever increases they are covered on something that may be difficult or impossible to change.

zcanyonboltz said:
I know its rebar connected by the "usual tie wires." We have been running number 6 and this must be okay with AHJ or the inspectors do not know, two of my inspectors are former JW electricians. I just don't see why a lot of other licensed electricians I talk with think the GEC is sized based on main breaker size and that's why the shop sends #4 for 200A and #6 for 150A I'm wondering why shop does this several companies I've worked for do the same thing.
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As I mentioned above GEC is sized to the service entrance conductors. Minimum size SE conductor needed for a 200 amp service will be large enough that a #4 GEC is needed, so many kind of get into the habit of going by main breaker size and usually are right but for the wrong reasons. But should you run larger then 3/0 copper or 250 aluminum service conductors because of voltage drop even though you only have a 200 amp main breaker - 250.66 will call for a larger GEC.
 
kwired said:
Grounding electrode conductors are to be sized in accordance with the size of the largest ungrounded service entrance conductors, or equivalent of parallel conductors. Look at the headings in table 250.66 - it says this right there.

250.52(A)(3)(2) is telling you if you use a piece of copper conductor as the electrode in the concrete it must not be smaller then 4 AWG.
250.66(B) tells you the GEC that solely connects to a CEE need not be larger then 4AWG. Most run 4 AWG anyway even if they could run smaller - that way if the service size ever increases they are covered on something that may be difficult or impossible to change.

As I mentioned above GEC is sized to the service entrance conductors. Minimum size SE conductor needed for a 200 amp service will be large enough that a #4 GEC is needed, so many kind of get into the habit of going by main breaker size and usually are right but for the wrong reasons. But should you run larger then 3/0 copper or 250 aluminum service conductors because of voltage drop even though you only have a 200 amp main breaker - 250.66 will call for a larger GEC.
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Thanks! I do know that the GEC is sized for ungrounded conductors not main breaker size.That's why I was saying for expansion if you don't change the size of the SE conductors you would not have to change the size of the GEC to the ufer and I couldn't figure out why the shop sends bigger copper wire for bigger main breaker.

250.52(A)(3)(2) is telling you if you use a piece of copper conductor as the electrode in the concrete it must not be smaller then 4 AWG.

Thank you! myself and many others are reading this wrong thinking the code reads not smaller than #4 copper must be run to ufer not USED for ufer. Now I know on many of the jobs with 200A service #6 is okay because of the laterals are still 1/0 or 2/0 Aluminum.
 
zcanyonboltz said:
Thanks! I do know that the GEC is sized for ungrounded conductors not main breaker size.That's why I was saying for expansion if you don't change the size of the SE conductors you would not have to change the size of the GEC to the ufer and I couldn't figure out why the shop sends bigger copper wire for bigger main breaker.

250.52(A)(3)(2) is telling you if you use a piece of copper conductor as the electrode in the concrete it must not be smaller then 4 AWG.

Thank you! myself and many others are reading this wrong thinking the code reads not smaller than #4 copper must be run to ufer not USED for ufer. Now I know on many of the jobs with 200A service #6 is okay because of the laterals are still 1/0 or 2/0 Aluminum.
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Service drop or service lateral doesn't matter, it is the service entrance conductor that determines the size of EGC needed.

Sometimes that can be the same conductor, but the point of entry is where the transition from service lateral or underground service conductor to service entrance conductor happens in those cases.

If you have a 2/0 aluminum service entrance conductor supplying a 200 amp breaker you have too small of a conductor, but POCO could run a 2/0 aluminum service drop and you run 4/0 aluminum up the riser/mast on a 200 amp service.
 
kwired said:
Service drop or service lateral doesn't matter, it is the service entrance conductor that determines the size of EGC needed.

Sometimes that can be the same conductor, but the point of entry is where the transition from service lateral or underground service conductor to service entrance conductor happens in those cases.

If you have a 2/0 aluminum service entrance conductor supplying a 200 amp breaker you have too small of a conductor, but POCO could run a 2/0 aluminum service drop and you run 4/0 aluminum up the riser/mast on a 200 amp service.
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Thanks I meant service drop or lateral and SEC. On some jobs we use meter combo panels and the POCO runs 1/0 to our 200 panel and the lateral gets connected to the panel with no SEC so that what I was thinking of. Now why the POCO runs 1/0 to our main is another post. On some projects we then run 4/0 SER to a sub panel in the utility room and we often talk about how riducouls it seems that POCO runs 1/0 laterals and we feed a 200A sub from disco with 4/0 SER.
 
zcanyonboltz said:
Thanks I meant service drop or lateral and SEC. On some jobs we use meter combo panels and the POCO runs 1/0 to our 200 panel and the lateral gets connected to the panel with no SEC so that what I was thinking of. Now why the POCO runs 1/0 to our main is another post. On some projects we then run 4/0 SER to a sub panel in the utility room and we often talk about how riducouls it seems that POCO runs 1/0 laterals and we feed a 200A sub from disco with 4/0 SER.
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I guess if POCO runs it there isn't much you can do about it - they don't have to follow NEC. If they run a 2/0 to your service disconnect then you size your GEC according to 2/0.

Most of the time, especially for residential work, if you just run 4 AWG to the CEE and 6 AWG to ground rods you can't go wrong, it is water pipe electrodes or building steel that will get you in trouble when those exist if you don't pay attention.
 
kwired said:
I guess if POCO runs it there isn't much you can do about it - they don't have to follow NEC. If they run a 2/0 to your service disconnect then you size your GEC according to 2/0.

Most of the time, especially for residential work, if you just run 4 AWG to the CEE and 6 AWG to ground rods you can't go wrong, it is water pipe electrodes or building steel that will get you in trouble when those exist if you don't pay attention.
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Thanks , I re read my previous post and for overhead drop you would have SEC so the GEC would be sized by SEC for overhead but not always for underground laterals.

Now just how to point out to my supervisor/projects manager that he is reading the code book wrong when telling me the ufer says not smaller than #4 copper, he had me thinking what???
 
zcanyonboltz said:
Thanks , I re read my previous post and for overhead drop you would have SEC so the GEC would be sized by SEC for overhead but not always for underground laterals.

Now just how to point out to my supervisor/projects manager that he is reading the code book wrong when telling me the ufer says not smaller than #4 copper, he had me thinking what???
Click to expand...

The CEE has to be #4 or larger, the GEC to the CEE can be smaller.
 
zcanyonboltz said:
Thanks , I re read my previous post and for overhead drop you would have SEC so the GEC would be sized by SEC for overhead but not always for underground laterals.

Now just how to point out to my supervisor/projects manager that he is reading the code book wrong when telling me the ufer says not smaller than #4 copper, he had me thinking what???
Click to expand...
If an underground conductor is unspliced then it becomes the service entrance conductor at the point of entry to the bulding. If you don't have a service entrance conductor you assume an equivalent sized service entrance conductor. Another place this applies is if the service entrance is busway.
 
ptonsparky said:
Be happy that you are even there to install one. Still getting to new buildings with no CEE connection. You would think 12? years would be long enough to get the word out.
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It probably would be "heard" if electricians actually were on site before foundation pours.
most of the time walls have been already poured and structure started by the time we get there.
Unless it's some huge job where under slab conduit runs will be installed.
 
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