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

This is how they do the Ufer here. Copper thieves made leaving a 4 ga sticking out of the slab a non-starter. They paint that core green so it doesn't get poured solid along with the doweled cells. It gets covered by a 4x4 blank.

The gec only needs to be continuous to the first rod. Between rods is a jumper under the NEC.

That is technically correct but there are still some crusty old inspectors who say both rods are "the electrode" since you haven't demonstrated one is under 25 ohms. In the practical sense, if they are both installed at the same time, there is no real reason not to loop the conductor through the acorn on the first rod and continue to the second one. Material cost is the same and it doesn't really change the time. It might even be faster. I wouldn't argue either way as long as all the parts are properly listed.

Just an FYI, there are some inspectors that have an issue with the two (2) conductors under the acorn. That is IF the #6 is not a continuous piece. AFAIK the acorn is not listed for multiple conductors.

That said, although we all have come upon a lot of 'conductors' under the acorn, be it telco, cable, dish, etc.

A couple of gripes then I’ll make my point.
First, I’m delighted this thread is starting discussion 😁. That’s what forums are for.
I do wish the board saw greater participation by the folks who actually do the work. They have a different perspective from others, different concerns.
It’s interesting to step back and look at how our views about the ground rod have changed over time. Electrical power has been with us a fairly short time — about 150 years — and, frankly, for the first fifty years nobody really knew what they were doing. This is reflected in the conflicting concepts about grounding.

Why all this fuss about ground rods? Ultimately the ground rod is there only because lightning exists. The ground rod is completely irrelevant to the power company — notice how Norway gets along just fine without them.
Has anyone ever seen an instance where the existence of a ground rod really mattered? Yet look at the minutia in the code on the topic. I can think of no other code section where yesterday’s theories have so often been contradicted by today’s doctrines. But I ramble ….

As to the means of connecting the first ground rod to the second:
— Don’t forget that the two rod requirement has been around only twelve or fifteen years. This means that most service upgrades will require a second rod.
— Acorns are relatively cheap. There’s nothing wrong with using two on a rod ( one for the wire to the panel, another to connect the rods to each other).
— Multiple wires under clamp just seems wrong.

A further general observation about grounding: Got CSST? Let the argument begin!
IMO, when CSST is used in place of iron gas pipe, you need to somehow connect the meter end to the EGC.

I do more service upgrades than new installations. So that usually means I'm pounding two ground rods.

-- Do you drive the rods below grade?
Yes, If I didn't I'd be creating a tripping hazard and violating code for not having 8' of the rod in contact with the soil.

— If so, how are the connections inspected?
I have seen inspectors kick dirt away, but generally the local inspectors know my work and they are more focused on the more critical parts of the install, bonding, etc. I suppose they could require me to dig it back up or leave it exposed.

— What tool is used to drive the rods?
Sledgehammer, sometimes, if the soil is decent they will push in part or some of the way. I do have an adapter for the rotary hammer drill. That is my preferred method.

— What wire do you use?
#6 or #4 solid.

— How do you protect the above-grade portion of the wire?
Generally I try to run it so it is not exposed to physical damage. Occasionally I will sleeve it in sch 80 PVC but usually more for looks than protection.

— Do you bond the wire to the buried end of the conduit? How?
I would never use a metallic wiring method to do this, only sch 80 PVC.

— How do you connect multiple rods together?
I generally loop my wire through my clamps. I have used copper C crimps and added on to existing GECs.

— Do you take any steps to protect the wire connecting multiple rods?
I bury it several inches deep as close to the building as possible.

As to the last post I would never run two wires under one acorn. One or nothing. CSST? The only time I run into an issue there is when I wire furnace change outs in a city inspected area where the electrical inspector also inspects the heating/ gas. He wants me to bond the CSST even though its really not in my scope of work. I feel that if it was suppose to be bonded it should have been done when the building was built. I can either tap on to the GEC to the ground rod outside and run to the fitting on the gas meter, or they allow me to run a #6 from the water main or main service panel to the indoor gas manifold. Usually its the second choice. Since its not a GEC or part of the electrical system, they are fine with mechanical means rather than an irreversible connection.

Nope. One per acorn. Go to your truck and get another one for another wire. That is why I said it is probably cheaper to just loop the wire through. That is the same as trying to get 2 wires in a breaker with a single wire lug. One of them is not getting proper clamp pressure. There are clamp type connectors that are listed for multiple wires (multiple holes) but a lot of them are not listed for burial.

I will disagree about the need for a good grounding electrode. Yes lightning and surge protection requires a good ground reference that everyone uses (PoCo, Cable, Telco, Satellite).
There is also a safety issue. If you are counting on the PoCo ground for a reference in wye distribution, expect to see several volts between their neutral and the actual dirt under your house, concrete floors, water pipes etc. It was enough to wake me up when I first moved here. Everything "grounded" would give you more than a tingle if you were barefoot on the terrazzo floor. I found the ground clamp, not listed for burial, had rusted off (bolts failed). I had some bronze ones in my truck from doing raised floor bonding and a new clamp fixed the problem but it did point out the value of the ground electrode. I grew up with copper service pipe going to cast iron that went everywhere so we always had a good ground. In fact you could lift the neutral and usually nobody would ever know. You were using your neighbor's neutral.
I did a study some years ago about how much stray current there is is my single wire wye distribution here. There are a few amps on my neutral with the main breaker off, coming from the utility and the pole ground wires run from less than 1 to over 3 amps.
You can talk theory all day long but Dr Ohm always wins. The voltage drop in the utility neutral shows up as a voltage rise on your neutral and that 4 gauge wire stapled to the bottom of the pole and going up to the transformer is no match for the current imposed on it. That is their ground electrode.

I remember a number of years ago doing some plumbing work at my grandmas house- I was replacing a section of galvanized pipe with copper. I had remove the clamp for the GEC. (When that service was installed it was still up to code to connect near the panel and rely on the piping as long as you still had the meter jumped out). I put my clamp on ammeter and it was drawing 10 amps. It did draw an arc when I disconnected it, but checking with a dmm, there was no difference in potential. That told me that one of the neighbors neutrals is probably compromised. Much more recent we were connecting a new GEC to the water main for a 600A service upgrade in a downtown building, and witnessed quite a bit of arcing upon disconnection of the old GEC. Still no difference in voltage.

One should really tread lightly in these instances, some or most of that current could be the utilities neutral current due to parallel paths and marginal connections.

Those utility neutral imbalance stories all seem to involve water pipes carrying current between houses because of a failed neutral at one house.
Voltage gradient stories seem to all involve a utility trying to use Mother Earth as a deliberate neutral return path, or an industrial facility with an ungrounded distribution network. Amazing how hard folks try to eliminate one wire!

Ground rods, by comparison, aren’t there for anything but lightning. Look at where they’re required — each discrete target gets rods.

Ever wonder about where the six foot spacing or eight foot length comes from? The American Electrician’s Handbook has the data. Those are the approximate points where greater spacing or longer rods show “diminishing returns:” increases show very little improvement.

Look at it this way: electricity wants to “go home” to the transformer where it originated. The only electricity that originates in the earth is static electricity— which is primarily lightning.