ECN Forum Forums General Topics of the Trade General Discussion Area Ground Rods: Installation and Hook-Up

One of the crazy McIver setups I came upon was 3/4" EMT, compression connector, 3/4" pipe coupling, and a "Kenny Clamp" for a choke/bond. 110.3(b)?? I had a good laugh. The cost overruled the purpose.

He said, "I could use PVC???"

I want to, again, thank everyone for their participation -- and your kind words!
With my threads it's not my purpose to preach or to brag. I post these topics as a way to invite discussion. Far to many forums stifle intelligent, respectful discussion, with comments too often limited to either "Here's how it's done" or "the code says . . . " Far too many comments sound, to my ears, like they come from an easy chair that has never seen a rainy day in the mud of a job site.

Let's look at the "official" connector and its use in more detail:
-- As mentioned, supply houses in the Mid-South have been unable, or unwilling, to obtain them. I just didn't have time for an internet order. While PVC might have worked, a look at routing of the pipe suggested to me that the exposed PVC would not survive long. I wasn't willing to either cut up the concrete slab or speculate as to the location of the foundation footings.
-- The "official" fitting is sized for 1/2" pipe. Only today, looing deep into the catalog, did I learn it's also made with a 3/4" hub. Ever try pushing #4 solid through bent pipe? I bet you quickly decide to violate the code requirement to "complete the pipe THEN pull in the wire, and instead put the wire in the straight pipe and bend it later!

-- Again, looking at the spec sheet, I discover bothersome detail: the connector with the 1/2" hub is designed for wire no larger than #6 solid. Well, that might explain some of the troubles I've had mounting #4! As designed, the wire is supposed to go under a brass fender washer and wrap around a screw, coming to rest in a nice circular groove. The only way I've been able to do that with #4 is to heat the wire with a torch, bend it, then trim off the tail. Then I find it necessary to replace the provided screw with a slightly longer one and re-assemble.
-- Note that the "official" connector comes with zinc plated steel screws. The spec sheet makes no reference to direct burial.
-- As a final note, the "official" connector does not lend itself to having the wire pass through and on to a second rod. (Erico, are you listening?)

Reno,

I have to ask, why do you use #4 solid to the rods ??

You mean there are other choices? 😁.

Use of #4 solid has been mandated by local standards since the early Seventies— at least in Chicago and Reno. Even here (Memphis, Arkansas, and the Missouri boot heel) the use is routine. It was one of the few things about my service change that didn’t surprise the local suppliers.

Even though the NEC is quite clear that a GEC need not be larger than #6, and is silent regarding solid or stranded, local rules are common. Let’s review how we got here.
The first homes to have any manner of grounding often had a small (#10) wire connected to a water pipe. By the early Sixties the addition of a ground rod had become common, still using a small wire.
As Americans moved to the suburbs, these wires came into conflict with lawnmowers. This led to locales asking for ever larger wires, until #4 solid was accepted as “tough enough.”
Then came the weed hacker — and, by the late Seventies, a sharp rise in copper prices. Various surveys and inspections revealed the ground wires were either damaged or missing. Thus, protecting the wire with conduit became the norm. Living outside Chicago at the time, PVC was never an option.

I've attached two pictures of the most common GEC install in this area.

I believe the intersystem ground buss is what HotLine described earlier. I don't like the way it interrupts the conduit and eposes the wire. That's why I much prefer the way the Ideal fitting connects to the panel as well as the pipe. I'm not worried about the connections to the data/phone/etc. grounds being exposed; those wires are usually just stapled to the siding.

In a similar manner, the GEC is exposed at the connection to the ground rod. Again, I don't lie the way the conduit is left dangling. Had I been able to get the proper fitting, I would have run the pipe all the way to the rod. (At least the exposed wire will be buried and out of site).

Finally, note #4 solid is used.

I see the EGC coming into the meter can. Do you land it there or take it to the service disconnect enclosure?

The 4ga thing came from older cycles of the code when 250.64(B) said

Although they didn't explicitly say 4ga did not need protection, that was the way it was read unless it was subject to physical damage, whatever that means.
Solid was seen as being tougher than stranded.
It really got down to what the inspector expected to see.
The reference to 4ga went away in 2017

Greg, I didn’t do the job with the PVC conduit, so I don’t know what was done.

As for my job, the panel had both the disconnect and the meter base, so I simply landed the GEC on the ground buss.

When I installed a bank of meters for an RV park (individual meter bases), I landed that GEC in the disconnect. IIRC, the meter socket neutrals were factory bonded to the enclosures.

Yup, that has been the issue here. It was becoming standard to land the EGC in the meter can. Then the debate got started that you now had a parallel neutral if the nipple through the wall was metal. They did massage the language in Article 250 a little in regard to "service equipment" but we still had some old timers who thought it was wrong. As far as I was concerned, I really didn't care about things that happened on the line side of the MBJ. That was the place where we worried about neutral and ground going off on their own path, never to meet again.

Okay, now I see where this is going . . .
I once got an emergency “power out” call from a major industrial customer on Thanksgiving. Seems their computers were down and there were some crazy power quality issues. The cause turned out to be degraded bonding between panels.
In this particular place — which had been built by the very guy who got the Ufer into the code — the main service had mounted right next to it three large panels, all connected together by RMC nipples. In each panel the ground buss was bonded to the neutral buss. For the brief space between the panels and the main disconnect, the pipe was acting as both neutral and ground, just carrying the current imbalance. Loosening and corrosion, over time, had made this a path with great impedance. Separating the grounds from the neutrals and extending the neutral from the panels back to the main disco solved the problem.

That’s where this discussion is getting off track. We are NOT talking about (fault) ground paths here. We are talking about the GEC — a wire that some modern countries don’t even use. The GEC if of relevance only for “natural” electricity — that is, static and lightning. That’s the only electricity that has any interest in going to earth. PoCo power wants to go back to the PoCo transformer where it was made.

The idea is: Each lightning target gets one GEC network. For an example like the PVC service pictured (meter base serving a disconnect right next to it, on the same structure), I would say the preferred practice would be to run the GEC to the meter base rather than the panel. After all, lightning will hit the meter can first . . .