code year for ground rods?

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SEO

Senior Member
Location
Michigan
The oldest code that I have is the 1937 NEC and the 8' rod is listed in section 2578. The 25 ohm resistance is in section 2579 and if 25 ohms in not met two or more electrodes connected in parallel shall be used.

480 Sparky will be able to go back further.
 
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delfadelfa

Member
Location
Cincinnati, OH
I'm just asking because houses that I go into that were built in the 60's or before with the original service never ever have a ground rod. I wanted to know if you had an original service without a ground rod and the whole house inspector said you needed one, was it grandfathered in that you do not need one because when the service was installed when it was not code? So you do not have to add one unless the service or panel are changed. But if your going back to 1937 and it was code then, why are so many rods not installed? All of these houses do have a water ground but not a rod.
 
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delfadelfa

Member
Location
Cincinnati, OH
SEO said:
The oldest code that I have is the 1937 NEC and the 8' rod is listed in section 2578. The 25 ohm resistance is in section 2579 and if 25 ohms in not met two or more electrodes connected in parallel shall be used.

480 Sparky will be able to go back further.
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I have a Abbott NEC handbook based on the 1940 code. Section 1906 talks about driving a rod when a water pipe is not available and I can not find where water and rod are required by code anywhere. Section 2579 must have been deleted because it is not in the 1940 code.
 
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delfadelfa

Member
Location
Cincinnati, OH
inspector 102 said:
The oldest NEC I have is 1978 and it is in there under 250-83.
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In my copy of the 1978 code, page 376, section 250-81, third and forth paragraph are as follows:

Up to the 1978 NEC, the "water-pipe" electrode was the premier electrode for service grounding and "other electrodes" or "made electrodes" were acceptable only
"where a water system (electrode)...is not available." If a metal water pipe to a building had at least 10 ft of its length buried in the ground, that had to be used as the grounding electrode and no other electrode was required. The underground water pipe was the preferred electrode, the best electrode.

In the 1978 NEC, of all the electrodes previously and still recognized by the NEC, the water pipe is the least acceptable electrode and is the only one that may never be used by itself as the sole electrode. It must always be supplemented by at least one "additional" grounding electrode. Any one of the other grounding electrodes recognized by the NEC is acceptable as the sole grounding electrode, by itself.

Is the 1978 code cycle what I am looking for???
 
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delfadelfa

Member
Location
Cincinnati, OH
jwelectric said:
go back and read 250-81 and 250-84
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I already quoted the 1978 code 250-81 and 250-84 only talks about testing ground rods for ohm resistance.

250-81 gives the grounding requirements before and after 1978. If I am reading 250-81 right, before 1978 you were not required to drive a ground rod if you had 10 feet of water line buried in the ground.
 
480sparky

480sparky

Senior Member
Location
Iowegia
dSilanskas said:
Wow that is one old code book :)
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1897:

DSC_8459.jpg
 
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bphgravity

Senior Member
Location
Florida
The first edition of the code to contain the 25-ohm section was the 1918 edition. Also in the 1918 edition, the first allowance for pipe electrodes became code. The original requirement permitted a minimum of a 1-in pipe with no less than 4-ft? of surface to exterior soil. The 1923 edition added the driven rod.
 
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