How many ground rods

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Our state requires 2 ground rods and the waterpipe if it is present and qualifys as an electrode.
 
roger said:
Thanks, I may be missing it but I don't see anything ammending the NEC grounding requirements though.

Roger
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I thought thats what the ahj told me , i know it is adopted in some states. Anyway the two ground rods is accepted here without an ohm test. When I said they dont want the water pipe connected that was bad wording . I meant to say that is because almost all the water pipes are plastic. I only remember doing one house that was old enough to have metal pipes that had not been replaced. And they did want that bonded. On commercial copper water lines it has to be examined to determined if it is allowed to be the main ground . Some are plastic as soon as or before they enter the ground .
 
electricmanscott said:
The thread is about service upgrades in existing dwellings. ;)
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Scott, I know you know the answer to this: Is it really any different than new work requirements?


As an inspector, I would see more screwed up installations with ground rods. From spacing to cut rods, to no rods to wrong size conductors, to conductors installed to the wrong location, to AHHHHHHHHHHHHHHHHHHHHHHH!!!!! ;):D


Now I just sit at home and type on my keyboard going AHHHHHHHHHHHHHHHHHHHHHHHH!!! :cool::D
 
Pierre C Belarge said:
Scott, I know you know the answer to this: Is it really any different than new work requirements?


As an inspector, I would see more screwed up installations with ground rods. From spacing to cut rods, to no rods to wrong size conductors, to conductors installed to the wrong location, to AHHHHHHHHHHHHHHHHHHHHHHH!!!!! ;):D


Now I just sit at home and type on my keyboard going AHHHHHHHHHHHHHHHHHHHHHHHH!!! :cool::D
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LarryFine said:
Does that pay as well as electrical work? ;)
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Where do I apply and can I work from home?:D
 
jetlag said:
Most places allow 2 rods with no ohm test .
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If they are using the NEC for their code they have to accept two rods with no test.

There is no NEC requirement for multiple rods to meet any minimum resistance.

Roger
 
LarryFine said:
Does that pay as well as electrical work? ;)
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cowboyjwc said:
Where do I apply and can I work from home?:D
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Well, yes of course. The overhead is very low, the stress is almost nonexistant, the bathroom is cleaner and the food is better.

Just thinking about it makes me say..................AHH! :cool:


John
For a SMALL fee, I will teach you the secret to a quiet success.;):D
 
roger said:
If they are using the NEC for their code they have to accept two rods with no test.

There is no NEC requirement for multiple rods to meet any minimum resistance.

Roger
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Thanks Roger, the posts seemed to be disagreeing with me on that like it must be a state or local thing we do here that is not in the NEC . So what I said was true everywhere , 2 - rods no test required , if there are metal pipes they must be bonded , but the metal pipes do not have to count as the main ground if 2 rods are used. That way you dont have to worry about how good the pipe ground is , it is just a matter of metal pipes must be bonded. We run #4 bare ground to each, so If you want to say the pipes are the main ground , have at it .
 
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Under the NEC the metal underground water pipe has to be the "main" grounding electrode in that you have to run a GEC sized per Table 250.66 to the pipe, but you never have to run a GEC larger than #6 to a ground rod.
 
George Stolz said:
A Megger is not the correct tester to test electrode resistance to earth.
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Correct-here, the AF boys use what they call a Vibra-Ground or similar meter that runs $2000+ to test and certify grounds at 10 ohms or less on sensitive equip. Has one leg clamped to the rod in question, 2nd to a probe in the ground 20 meters away and 3rd 40 meters away. Thats why no one tests for <25 ohms. In MI, AHJ was a stickler and wanted metal u/g water as primary(if available) and then out to rod as second...or 2 rods.
 
don_resqcapt19 said:
Under the NEC the metal underground water pipe has to be the "main" grounding electrode in that you have to run a GEC sized per Table 250.66 to the pipe, but you never have to run a GEC larger than #6 to a ground rod.
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So you count the metal pipe as the main ground even if it changes to pvc before it enters the ground ? I dont think that will ohm out very well .. We have to run # 4 to the rods on a 200 amp service here and if metal pipes bond it with #4 , will you explain what difference it makes who calls what the main when it is done that way .If it makes you happy to say my rods are not the main my water pipes are , then who cares ? :roll:
 
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