GROUND rod

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That has been permitted by the code for many decades....well before I started in 73.

Not sure if it was ever legal, but dwelling unit services from the 60s and earlier around here not only used 3/4" conduit as the grounding electrode, but used 1/2" conduit as the grounding electrode conductor. They used a "service LB that had a 1/2" tap in the bottom and the 1/2" was run down into the ground, had a 90 on it, and was connected to the 3/4" pipe with a wedge clamp.
I have looked a couple of times for pictures of the wedge clamp without success.
 
I used some 3/4" galvanized heavy wall conduit back in the 1970's for ground rods. Usually had to get out my heavier 20 # sledge hammer to drive in the last few feet. Now with a ground rod attachment for larger hammer drills to drive in 5/8" ground rods fairly fast that is they only way to go. While at one of the big box store recently to get some Christmas tools mean gifts saw a ground rod driver for hammer drills that only cost a little over $40.
 
But how do you pound in a 3/4” galvanized EMT with thinner walls as you would a 1/2” rod?
 
Jpflex said:
But couldn’t you use emt if you had a hole dug 10 feet?
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🤔
Let me go read that section. Driven comes to mind. However that may not be the wording.
3/4 galvanized EMT may be applicable. I'll go read it.

After all water pipe is laid in a trench.
I'm thinking this is where the pipe electrode came from.

I'll get back to you. Thanks
 
LarryFine said:
No, because EMT technically isn't conduit or pipe.
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I wanted to add. From UL white book.
EMT (tubing)
Even if galvanized, UL requires additional protection if in Direct contact with earth. This would defeat the purpose of using it as an electrode.
So I would say it shall not be used.

UL has section for conduit and for tubing. NEC also uses this language. Ok to slang it as long as we know the difference. Some will argue however I'm ok with it as long as we're not teaching or testing.

This is one of those case the word conduit matters.
 

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don_resqcapt19 said:
That has been permitted by the code for many decades....well before I started in 73.

Not sure if it was ever legal, but dwelling unit services from the 60s and earlier around here not only used 3/4" conduit as the grounding electrode, but used 1/2" conduit as the grounding electrode conductor. They used a "service LB that had a 1/2" tap in the bottom and the 1/2" was run down into the ground, had a 90 on it, and was connected to the 3/4" pipe with a wedge clamp.
I have looked a couple of times for pictures of the wedge clamp without success.
Click to expand...

Yes, while in HS I worked Saturdays re-stocking trucks for an electrical outfit. This was in 1965-66.

We used a piece of 1/2 rigid conduit, that went into a 1/2 KO in the bottom RH back corner of the meter base (with a grounding bushing and jumper to the neutral conductor,) then down and thru a 90 bend to the 3/4" ground pipe also rigid conduit 10 ft long...One of my jobs was to make sure that there were always 8-10 pre-made 1/2" pieces in stock, as I recall it took a 6-ft 9-inch length with the bend that would place the 3/4 rod about 1`2 inches from the building foundation and a foot undeground.

And Don, it appears that pictures of that wedge clamp have been purged from existence....I've gone thru old Sears and MW 'farm' catalogs and no trace. It was a U-shaped piece of galvanized steel, the U was sized to fit around the 3/4 pipe, each end of the U had a hole large enough for the 1/2" to fit thru, and then the two wedges were driven into the 'corner' formed by the two pipes.
 
OldBroadcastTech said:
Yes, while in HS I worked Saturdays re-stocking trucks for an electrical outfit. This was in 1965-66.

We used a piece of 1/2 rigid conduit, that went into a 1/2 KO in the bottom RH back corner of the meter base (with a grounding bushing and jumper to the neutral conductor,) then down and thru a 90 bend to the 3/4" ground pipe also rigid conduit 10 ft long...One of my jobs was to make sure that there were always 8-10 pre-made 1/2" pieces in stock, as I recall it took a 6-ft 9-inch length with the bend that would place the 3/4 rod about 1`2 inches from the building foundation and a foot undeground.

And Don, it appears that pictures of that wedge clamp have been purged from existence....I've gone thru old Sears and MW 'farm' catalogs and no trace. It was a U-shaped piece of galvanized steel, the U was sized to fit around the 3/4 pipe, each end of the U had a hole large enough for the 1/2" to fit thru, and then the two wedges were driven into the 'corner' formed by the two pipes.
Click to expand...
That is how I remember the clamp too. Around here they always used the service LB with the 1/2" tap on the bottom. They were this type but with the 1/2" hub on the bottom for the 1/2" rigid that was used as the grounding electrode conductor. No wire conductor, the larger conduit to the service panel was bonding with a bonding bushing and GEC sized jumper in the service panel.37f69ed42cc21e40179a82c6fa08431a2f870560-large.pngI have a couple of friends who work in the area and have asked them to take some pictures if they ever dig one up...still a lot done that way in my area.
 
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