New construction questions

[David C. Macy]

In a 2005/2006 new build do the nuetrals & ground need to be isolated?

Also is this a UFER gound by the meter. Is this a new requirement?

[Jeffrey R. Pope]

This looks like the service equipment David. The grounds and neutrals are required to be bonded at the service equipment.

Generally speaking, grounding conductors are never "isolated." They are always bonded to their enclosures and/or equipment.

Neutrals are "isolated" at all points past the service equipment.

The rebar can be used for a Ufer, but there is no conductor attached. It looks like the water pipe is being used as the GE.

[David C. Macy]

Jeff

The home had an exterior ground rod & water line ground. I spoke with the builder & he stated that it was required for grounding purposes. It wasnt being utilized but there was no water meter installed and he stated it was for an option for the water company.

I didnt see the need for it as it had the other sources. I just questioned & he explained to me. This builder was very knowledgeable and was a pleasure to work with.

I thought I read about new construction that The ground & nuetrals should be seperated at the main as well. What you say makes sense.

Thanks

[Jeffrey R. Pope]

This is a "supplemental" grounding electrode. The ground rod is typically the primary, and the water pipe is the secondary. This is common in new construction where a ufer is not used.

The neutral is the grounded conductor (a current carrying conductor), which can only be (and must be) grounded at the service equipment. If it is grounded or bonded anywhere else, it can energize the component it is attached to. That is why it must remain "isolated."

[Paul W. Abernathy]

If they are under the 2005 NEC in your area and the UFER is their in plain sight then it would have to be used in this case because it is present....in new construction.....




Part III. Grounding Electrode System and Grounding Electrode Conductor


The words “if available” have been replaced with “are present.” The effect is that a concrete-encased electrode (Ufer) is always required for new construction, because it is present. However, a new exception adds clarity that a concrete-encased electrode [250.52(A)(3)] isn’t required for existing buildings or structures.

All grounding electrodes as described in 250.52(A)(1) through (A)(6) that are present at each building or structure must be bonded together to form the grounding electrode system. Figure 250-15

Ex: Concrete-encased electrodes are not required for existing buildings or structures where the conductive steel reinforcing bars aren’t accessible without disturbing the concrete.

[Speedy Petey]

A metallic water pipe is regarded as the primary electrode. It must then be supplemented by a rod or other electrode.

Under NEC 2005, if there is ANY rebar a Ufer MUST be used, in sight or not. There is no distinction to it being burried in conctrete. This was the change from the word "available" and "present" Paul mentioned.
With a Ufer, there is NO requirement to "add" any other electrodes if they are not "present" at the installation.

For instance, at a home fed by a well with plastic pipe the ONLY electrode required is the Ufer (provided rebar is present). NO supplemental rod is required. This is good part about Ufers being mandatory.

For a home fed by a metallic water pipe, the water pipe IS the primary electrode, and the Ufer is the supplemental.

[Jeffrey R. Pope]

Well, it's almost 2007, in which case, CA will likely adopt the 2005 NEC. So, I guess it's time that I start getting familiar with this "new" code

[Paul W. Abernathy]

Me just LOVES a UFER ground........I sent out a letter to all the builders in my area to start installing them if available....I like EM...

[Paul W. Abernathy]

lol...Jeff....think about me here in VA....I do classes on 1999, 2002, 2005 and starting to get ready for 2008......sometimes I worry about my brain and when it will start to smoke.......

Heck...in VA...we just adopted 2002.....and it is now 2006.....so i figure will adopt 2005 at around 2009 and then 2008 in the year 2011.