GEC

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Djelite

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When using a water main pipe as a gtounding electrode it needs to be supplemented. When you supplement with a ground rod do you only need one ground rod or do you need two if you dont have 25 ohms?
 
A single ground rod is only considered a grounding electrode when it has been tested to prove 25Ω or less. If you are not testing the single rod then two rods are required.
 
infinity said:
No it needs to be supplemented by another electrode. A single rod unless tested and proven to be 25 ohms or less is not an electrode.

250.53(2) Exception
Click to expand...
That's not the way I'm reading it. It says if the pipe, rod, or plate meets the 25 ohm, then no additional electrode needed. So if the pipe didn't meet it, then a rod added would satisfy that. It doesn't say a single rod is not an electrode.
One pipe + one rod = satisfied

(2) Supplemental Electrode Required. A single rod, pipe, or
plate electrode shall be supplemented by an additional electrode
of a type specified in 250.52(A)(2) through (A)(8). The
supplemental electrode shall be permitted to be bonded to one
of the following:
(1) Rod, pipe, or plate electrode
(2) Grounding electrode conductor
(3) Grounded service-entrance conductor
(4) Nonflexible grounded service raceway
(5) Any grounded service enclosure
Exception: If a single rod, pipe, or plate grounding electrode has a
resistance to earth of 25 ohms or less, the supplemental electrode shall
not be required.
 
250.53(D)(2) states:
If the supplemental electrode is of the rod, pipe, or plate type, it shall comply with 250.53(A).

which, when you look at 250.53(A), to me, indicates you need the two rods unless you meet the 25 ohm rule.
 
augie47 said:
250.53(D)(2) states:
If the supplemental electrode is of the rod, pipe, or plate type, it shall comply with 250.53(A).

which, when you look at 250.53(A), to me, indicates you need the two rods unless you meet the 25 ohm rule.
Click to expand...
I think you’re right
 
Little Bill said:
That's not the way I'm reading it. It says if the pipe, rod, or plate meets the 25 ohm, then no additional electrode needed. So if the pipe didn't meet it, then a rod added would satisfy that. It doesn't say a single rod is not an electrode.
One pipe + one rod = satisfied
Click to expand...
Sorry about that I gave the wrong code reference but the answer is the same being the bold is incorrect unless the single rod is tested. Augie gave the correct code reference.
 
augie47 said:
250.53(D)(2) states:
If the supplemental electrode is of the rod, pipe, or plate type, it shall comply with 250.53(A).

which, when you look at 250.53(A), to me, indicates you need the two rods unless you meet the 25 ohm rule.
Click to expand...
You're supplementing the pipe because a single pipe, if not tested, doesn't meet the 25 ohm. The rod is the supplement. It would be the same way if it was a rod and needed supplementing, the pipe would satisfy that.
250.53(A) is what I posted above. It (the exception) says if you only have a single rod, pipe, or plate and it does meet the 25 ohm, then no supplement electrode needed. And since the pipe was not tested it does need a supplement and the rod would be that.
 
Little Bill said:
You're supplementing the pipe because a single pipe, if not tested, doesn't meet the 25 ohm.
Click to expand...
Note the water pipe doesn't have an allowance for checking that the resistance to ground is 25 ohms or less. The water pipe always needs a supplemental electrode. 250.53(D)(2).

Little Bill said:
The rod is the supplement. It would be the same way if it was a rod and needed supplementing, the pipe would satisfy that.
Click to expand...
250.53(A)(2) specifies that the supplement to a ground rod be an electrode "of a type specified in 250.52(A)(2) through (A)(8)". That means that a water pipe, which is the type in 250.52(A)(1), may not be the supplemental electrode to a ground rod.

The upshot is that you need the water pipe and two ground rods, unless you confirm that one ground rod is 25 ohms or less to remote earth.

Cheers, Wayne
 
I found it in the later articles which then was addedto the language of 250.53. It has to be 25 ohms or less in any scenario or two rods are needed
 
I found it in the later articles which then was addedto the language of 250.53. It has to be 25 ohms or less in any scenario or two rods are need
 
Little Bill said:
You're supplementing the pipe because a single pipe, if not tested, doesn't meet the 25 ohm. The rod is the supplement. It would be the same way if it was a rod and needed supplementing, the pipe would satisfy that.
250.53(A) is what I posted above. It (the exception) says if you only have a single rod, pipe, or plate and it does meet the 25 ohm, then no supplement electrode needed. And since the pipe was not tested it does need a supplement and the rod would be that.
Click to expand...
You are confusing water pipe with a piece of grc used for an electrode piece of pipe.
 
In nyc we have to go full size to to the water piping system. The water piping system in the ground is your grounding electrode it needs to be supplemented so we use a rod that rod get a #6 gec. I wasn’t sure if you needed one or two but Augie was correct inhis info and code reference. I also found it in earlier codes which refers you to 250.53 and like Infinity stated it must be one rod tested for 25 ohms or less or two rods
 
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