EGC to ground rod via PVC conduit


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Old 09-12-08, 09:32 PM
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EGC to ground rod via PVC conduit

I'm running my #6 solid bare EGC wire to the ground rod through PVC conduit. Do I just let it run out the end of the conduit (which will be buried underground), no clamp required? Or does it need a clamp, like when NM exits EMT when EMT is sleeving NM for protection?

Thanks,
Rick
 
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Old 09-12-08, 10:14 PM
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Not so sure I see a need for a connector but then again, I don't see a need for the PVC either.... Your not required to protect your EGC when it exits the house. Atleast not that I'm aware of. I suppose a lawn mower might be a different story but that's why you run it slightly below grade.

Might want to wait for more input.
 
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Old 09-12-08, 10:35 PM
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I believe it needs to be #4 to satisfy the no protection rule. I would run #4 minimum in any event even if charts show you can get away with #6.

It is so easy to break even #4 solid. All you have to do is lightly score it with a pair of cutters and bend and break it. Standed would fair much better.
 
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Old 09-12-08, 10:45 PM
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Typically the #6 will useally need protection but #4 useally not but most of the time I do run it for potection and also it look little better that way.

Some area they don't need end NM or other type of clamp to hold the #6 or #4 but check with your local code it may raise some issue but be on safe side to verify it with your local inspector for it

Merci,Marc
 
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Old 09-12-08, 11:07 PM
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For my 200A service entrance, local codes require a EGC #4 CU to my water pipe (within 5 ft of entrance), and a #6 CU from my meter socket to the ground rod. I was going to go with solid for the ground rod, but I'm also planning on 270° of bends from the meter socket to the rod. I bought the solid and have realized that it's going to be tough to pull! Maybe I'll get some stranded #6 to help with the pull. The bends are because there is concrete directly below the meter and only a couple feet away is the edge and soil.

If a cable clamp is required, then is a female PVC fitting on the end of the conduit with a 'common' NM screw down cable clamp (like you'd use for clamping NM into a metal junction box) permissible? Is there a different/better way?

Thanks,
Rick
 
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Old 09-12-08, 11:13 PM
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Originally Posted by rockin_rick
For my 200A service entrance, local codes require a EGC #4 CU to my water pipe (within 5 ft of entrance), and a #6 CU from my meter socket to the ground rod.
Ok but you write that like the code requirement is an absolute. It is an absolute minimum but not a maximum. If you think mechanically #4 or heavier is better then use it. I happen to think #6 seems flimsy for 200A service especially knowing what lightning can do. I like to go on the conservative side. It depends if it is for, you or a job, I guess.
 
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Old 09-13-08, 08:49 AM
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Sorry if I sounded argumentative, I did not intend it that way. I just wanted to clarify my situation. I was also under the assumption that code states that no larger than a #6 EGC to a ground rod was due to the fact that the rod itself cannot 'handle' more current than a #6, so larger was unnecessary. Sorta like connecting a fire hose to a lawn sprinkler. Is my assumption incorrect? I'm guessing so, since you are advocating a larger conductor.

I also mentioned that to clarify that the ground rod was a supplementary grounding electrode, not a primary/only.

Regardless, you raise a good point, and I will consider that. Of course I think that #4 is better, but than again I also think that #2 is better. But where does it end? I was assuming that Code's 'no larger than #6' was the safe end, but maybe not? :confused

Is anyone certain about the clamp or how to clamp the conductor leaving the conduit? Or is it so loosely specified in Code, that it's up to local AHJ?

I'm not intending to be a smart ass, I can see how it may seem that way - In reality, I appreciate your insight, advice, and criticism.

Thanks,
Rick
 
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Old 09-13-08, 12:28 PM
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A clamp is not required by the NEC unless you are running metal conduit.

Now, local codes may sometimes overide the NEC and require other things to be done. I highly doubt that a local code will require a clamp where it exits the conduit but none of us here can give you definite answer unless we live/work in your city.

To answer your question, NO the NEC does not require a clamp on the end of the pvc conduit

couple of quotes from NEC

250.62 Grounding Electrode Conductor Material.
The grounding electrode conductor shall be of copper, aluminum, or copper-clad aluminum. The material selected shall be resistant to any corrosive condition existing at the installation or shall be suitably protected against corrosion. The conductor shall be solid or stranded, insulated, covered, or bare.


250.64 Grounding Electrode Conductor Installation.

(B) Securing and Protection Against Physical Damage. Where exposed, a grounding electrode conductor or its enclosure shall be securely fastened to the surface on which it is carried. A 4 AWG or larger copper or aluminum grounding electrode conductor shall be protected where exposed to physical damage. A 6 AWG grounding electrode conductor that is free from exposure to physical damage shall be permitted to be run along the surface of the building construction without metal covering or protection where it is securely fastened to the construction; otherwise, it shall be in rigid metal conduit, intermediate metal conduit, rigid nonmetallic conduit, electrical metallic tubing, or cable armor. Grounding electrode conductors smaller than 6 AWG shall be in rigid metal conduit, intermediate metal conduit, rigid nonmetallic conduit, electrical metallic tubing, or cable armor.


E) Enclosures for Grounding Electrode Conductors. Ferrous metal enclosures for grounding electrode conductors shall be electrically continuous from the point of attachment to cabinets or equipment to the grounding electrode and shall be securely fastened to the ground clamp or fitting. Nonferrous metal enclosures shall not be required to be electrically continuous. Ferrous metal enclosures that are not physically continuous from cabinets or equipment to the grounding electrode shall be made electrically continuous by bonding each end of the raceway or enclosure to the grounding electrode conductor. Bonding shall apply at each end and to all intervening ferrous raceways, boxes, and enclosures between the cabinets or equipment and the grounding electrode. The bonding jumper for a grounding electrode conductor raceway or cable armor shall be the same size as, or larger than, the enclosed grounding electrode conductor. Where a raceway is used as protection for a grounding electrode conductor, the installation shall comply with the requirements of the appropriate raceway article.
 
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Old 09-13-08, 03:17 PM
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The only thing you might want to do is seal the end of the conduit in the ground with silicone just to discourage ants, etc. from taking up residence in your meter socket. (Based on a recent experience)
 
 

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