Ground wire from panel mounts

[Sunking]

So, how do they do that in Palm Springs, unless the house is next to a golf course, there is no moisture level?

Or My house pad, which is about 25' of packed gravel (extending 10' beyond the foundation perimeter). No moisture in it unless it's raining. I guess the Code is still not totally de-bugged.

Mike you are stuck inside a box of thinking you have to use a Ground Rod. Fact is you do not have to have a single ground rod to have an acceptable functional Ground Electrode System (GES).

III. Grounding Electrode System and
Grounding Electrode Conductor
250.50 Grounding Electrode System


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. Where 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.

Rather than copy and paste of all of A1 through A8 the electrodes on site are:

1. Metal Under Ground Water Pipe
2. Metal Frame of Building or Structure
3. Concrete Encased Electrode Used in dessert conditions
4. Ground Ring or Radials
5. Rod or Pipe
6. Listed systems like a Chemical Ground Rod or Radial. Used in dessert conditions
7. Plate Electrodes most often used for large utility generators with a few thousand tons of concrete sitting on top of it.
8. Other Local Metal Under Ground Systems or Structures.

If none of the electrodes exist pick one from 4 through 8. Nothing says you have to use RODS. If you do use rods or pipes there are requirements to be met.

Today most all new construction use a Concrete Encased Electrode and the Under Ground Metal Water Pipe. No ground rod or number of ground rods can beat a properly built Concrete Encased Electrode (CCE). It is a take off of the Herbert Ufer ground who worked for Dupont during WW-II and was tasked to come up with a ground system to be used in military Ammunition Bunkers located in AZ dessert where static electricity control is a must. Ufer Ground is real simple where you bond the steel reinforcement bar used inside the concrete and either stub up a section of rebar so a ground wire can be welded or compressed, or just a section of wire bonded to the rebar sticking up through the finished concrete floor. Concrete has a massive surface area and concrete never dries out. Even a small foundation can achieve extremely low impedance of less than 10 ohms. You could pound a hundred rods and never reach that low of an impedance. NEC CCE is a modified version of a Ufer Ground that only requires either 20 foot of conductor in the the bottom of a Footer, or attached (bonded) to the rebar of at least a 20 foot section.

However I agree NEC leaves something to be desired sometimes. YOu woul dbe surprised how many EC's think a GES has to be 25 ohms or less. There is no such requirement.

[Sunking]

Thanks for the Mike Holt link. It seems to be not quite as black and white as you indicate in this forum. Consider this quote by 'infinity' the chief moderator:

Look at the post dates. He is quoting 2011 code cycle. 2014 was amended from "Where Practical" to "Shall Be". The tern Shall Be in code is not a conditional statement, it means it will be done with no exceptions.

[Sunking]

Breaking my promise to say nothing..............
So tell me then why is a ground wire allowed to be above the ground then? It is more prone to damage than a few inches of rod sticking up. My example mentioned the 10 foot rod as I recognize you'd have said at least 8 feet needed to be below ground level. If you are helping to make NEC rules and say such things here then it explains some things coming out of the NEC. Is there not a test of knowledge to be on the NEC making rules? Also, who came up with the term moisture level to be put into the rules? What an asinine vague term.

This tells me you are not in the profession.

[SolarShadow]

This tells me you are not in the profession.

Thanks for not addressing it with a valid answer. I proved my point.

[Sunking]

Thanks for not addressing it with a valid answer. I proved my point.

Give it up, you lost the debate.

[merc4]

sorry guys, I didn't mean to start an argument.

[russ]

sorry guys, I didn't mean to start an argument.

No problem - The solar shadow is gone.

[mapmaker]

That leaves us thermal capacity and longevity. This is where solid far outperforms stranded wire especially in the dirt.

Regarding the use of solid wire for a grounding electrode conductor, your logic makes perfect sense to me. But is it a requirement of NEC?

I've tried (but failed) to find language in the code that requires a solid GEC. But, I'm very new at trying to read the code, so it's not too surprising that I haven't found it if the language is there.

btw, in my area many (most?) homes use #6 stranded to connect to the ground rod. Of course, that doesn't make it right, but that is what I observe.

--mapmaker

[Sunking]

Regarding the use of solid wire for a grounding electrode conductor, your logic makes perfect sense to me. But is it a requirement of NEC?

I've tried (but failed) to find language in the code that requires a solid GEC. But, I'm very new at trying to read the code, so it's not too surprising that I haven't found it if the language is there.

No you can use, bare, stranded, insulated or bare. It is in 250.62

250.62 Grounding Electrode Conductor Material


The grounding electrode conductor shall be of copper, aluminum,
or copper-clad aluminum. The material selected
shall be resistant to any corrosive condition existing at the
installation or shall be protected against corrosion. The conductor
shall be solid or stranded, insulated, covered, or bare.

OK with that said you have some termination issues to solve, especially below ground level. Most Electrical Contractors (EC's)being what they are looking for fastest and least expensive method use solid because you can fine and use listed for Direct Burial Mechanical Clamps connectors for solid wire. Where as not so much for stranded wire for Direct Burial which usually requires either irreversible compression or exothermic thermal weld. DIY is kind of in the same boat as they do not have access to the proper tooling for compression and no way do they have access to the molds or training for exothermic welding.

In Telecom and data we do use stranded in certain situations. Quite a bit in fact with just about all bonding or equipment, raised floors is done with stranded because it is easier to work with and bend and run on equipment racks. But we use 2-hole compression terminals, and H-Taps which require training and special tooling.

As for using 6 AWG for the Ground Electrode Conductor (GEC) from the service to ground rod brings issues that have to be dealt with.


250.64 Grounding Electrode Conductor Installation


Grounding electrode conductors at the service, at each building
or structure where supplied by a feeder(s) or branch
circuit(s), or at a separately derived system shall be installed
as specified in 250.64(A) through (F).

(B) Securing and Protection Against Physical Damage.
Where exposed, a grounding electrode conductor or its enclosure
shall be securely fastened to the surface on which it
is carried. Grounding electrode conductors shall be permitted
to be installed on or through framing members. A 4
AWG or larger copper or aluminum grounding electrode
conductor shall be protected if exposed to physical damage.
A 6 AWG grounding electrode conductor that is free from
exposure to physical damage shall be permitted to be run
along the surface of the building construction without metal
covering or protection if it is securely fastened to the construction;
otherwise, it shall be protected in rigid metal conduit
(RMC), intermediate metal conduit (IMC), rigid
polyvinyl chloride conduit (PVC), reinforced thermosetting
resin conduit (RTRC), electrical metallic tubing (EMT), or
cable armor. Grounding electrode conductors smaller than 6
AWG shall be protected in RMC, IMC, PVC, RTRC, EMT,
or cable armor.

Then what catches my attention big time if the houses in your neighborhood are really using 6 AWG raises a Red Flag IMO that has to be looked at. In order to use a #6 AWG copper for the Ground Electrode Conductor (GEC) has to meet the requirements of 250.64 (2)

(2) Individual Grounding Electrode Conductors.

A grounding electrode conductor shall be connected between
the grounded conductor in each service equipment disconnecting
means enclosure and the grounding electrode system.
Each grounding electrode conductor shall be sized in
accordance with 250.66 based on the service-entrance
conductor(s) supplying the individual service disconnecting
means.

250.66 is a Table which I cannot cut and paste but what it is telling you is the minimum size GEC is based on the Service Entrance (SE) Feeder Cable size. To use a # 6 AWG copper, the SE cable must be 1/0 or smaller. Here is the catch. A 1/0 SE cable tells me a 100 Amp Service at most. So are you saying you live in a trailer park, apartment, or small house with a 100 amp or smaller service? Your standard 150 and 200 amp service uses a 2/0 or 3/0 SE cable and uses a #4 AWG copper GEC. See what I am saying?

[mapmaker]

To use a # 6 AWG copper, the SE cable must be 1/0 or smaller. Here is the catch. A 1/0 SE cable tells me a 100 Amp Service at most. So are you saying you live in a trailer park, apartment, or small house with a 100 amp or smaller service? Your standard 150 and 200 amp service uses a 2/0 or 3/0 SE cable and uses a #4 AWG copper GEC. See what I am saying?

Quite clearly, thank you very much!

The GECs that I have observed closely are indeed in older homes with 100 amp service... propane cooking and no air conditioners. I moved to my present off-grid home from a house I built in 1980 with 100 amp service.

btw, in all of these homes (including my former home) the 8 ft ground rods stick above ground a few inches, and the connection to the GEC is above ground. Once again, that doesn't make it right, but that is what I have observed. At least in Vermont the moisture level in the soil is not very far down.

--mapmaker

[Sunking]

btw, in all of these homes (including my former home) the 8 ft ground rods stick above ground a few inches, and the connection to the GEC is above ground. Once again, that doesn't make it right, but that is what I have observed. At least in Vermont the moisture level in the soil is not very far down.

Most likely means before the requirement was made. With that said a single or two grounds rods do not really do anything other than a reference point to earth. Its main function is in the event your service transformer faults primary to secondary, primary distribution falls on secondary distribution or your over head service lateral, or a lightning strike on the utility or your service lateral.

EDIT NOTE:

With almost all new construction, no one uses ground rods any more. With the new changes over the last 25 years almost all Ground Electrodes are Concrete Encased Electrodes built into the foundation in one of the Footers. Far superior to any rod, pipe, or plate electrode.