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anyone tell me where nec code talks about ground wire size?

anyone tell me where nec code talks about ground wire size?

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  #1  
Old 07-21-08, 01:01 AM
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anyone tell me where nec code talks about ground wire size?

running a subpanel, 60 amp to a shed. will be 4 wires 2 black
1 white 1 green. I bought a 500 foot roll of #6 in black at home depot because it was about 1/2 price of buying individual color marked wires. I was asking the inspector if it was ok to use the black wire for the white neutral and color code it and he said thats ok. Then I asked him for the ground if I could to a size #8, he said no since you bought the 500 foot roll lets keep it in phase and use size #6 for the ground.

ok problem I just measured the distance to the shed with everything considered I need about 145 feet per wire run. that means I can only get 3 wires out of my roll.

I have to buy a ground 145 feet. #8 wire is about $60 cheaper than #6. I know code says you can go 2 sizes bigger. The person at Lowes seems to know his stuff and he said you could fight it but you will need to know section of nec etc. He said alot of times best just to give inspector what he wants.

IS it usually best just to bite the bullet and give inspector what he wants? or if it isn't does anyone have the section of code from 2008 nec I could refer to if I wish to argue it?


Thanks in advance for help!
 
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Old 07-21-08, 04:57 AM
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I wouldn't fight the inspector, although you can use one size smaller grounding wire. The guy at Lowes won't be there when it is inspected, so it is between you and the inspector, and he will win. You can call him back up and tell him your new situation. He may let you do the #8 since you have to buy new wire anyway. Won't hurt to check. If you are using all black, be sure to color code the ends of the wires as you lay it. Normal SE will be coded as far as the neutral goes, but you won't have that luxury.
 
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Old 07-21-08, 08:41 AM
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Well, you won one and you lost one.

The inspector was overly-generous in allowing you to violate code by remarking a black #6 wire as a neutral. You might want to get that in writing, especially if some other inspector might be the one to come out and do the inspection. See section 200.6(A).

But he should have allowed you to use #8 or #10 for the grounding wire. If you care to discuss this with the inspector further, you might refer to Table 250.122 of the NEC (I'm looking at the 2005 NEC, but it's probably the same in the 2008).
 
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Old 07-21-08, 08:48 AM
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John Nelson .,, Just to head up with the #6 and larger the code do allowed to be remarked and it is very common pratice with that due the OP mention 500 foot spool so I automatically pretty much sure it is a THHN/THWN cable if correct then the code is right on spot.

Now for grounding wire.,,

For 145 foot run snag on # 8 and it will meet the code no question asked if need the chart number or referce number

NEC 250.122 { 2005 verison } ( the 2008 NEC is the same )

Merci,Marc
 
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Old 07-21-08, 08:52 AM
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Originally Posted by Tim T. View Post
Then I asked him for the ground if I could to a size #8, he said no since you bought the 500 foot roll lets keep it in phase and use size #6 for the ground.
How strange. For anything above 30A, the ground wire is almost never the same size as the hots. Table 250.122 allows a #10 copper ground for circuits up to 60A; #8 ground for circuits up to 100A; and #6 ground for circuits up to 200A. Clearly the #6 is way oversized for a 60A panel, but it's up to you as to how far you want to take it with your inspector.
 
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Old 07-21-08, 08:54 AM
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Marc,

Did 200.6(A) change in the 2008 code?
 
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Old 07-21-08, 09:00 AM
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John N.,,


AFAIK no they did not change the wording so it is carryover on 2008 code unless a local issue come up.

Merci,Marc
 
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Old 07-21-08, 09:43 AM
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thanks for the code and the advice!

I went ahead and called the inspector this morning and asked him.

He said #8 would be ok after all. I didn't have to use nec code or anything. It was good to know though just in case. I guess he was just saying originally you already have the wire just use it that type of thing... anyways thanks for the help and information good to know you can go 2 sizes up for future refrence!

p.s. yah it is thhn/thnw wire...
 
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Old 07-21-08, 10:22 AM
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There is no "2 sizes up" rule. So forget that rule. It isn't a rule. Instead, simply use table 250.122.
 
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Old 07-21-08, 08:13 PM
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200.6

John,
No change in 2008.
The code still says that the grounded conductor (#6 AWG or smaller) must be identified by a continuous outer finish.
It does not give the option to tape it.
 
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Old 07-21-08, 08:24 PM
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Thanks dezwit. That's what I thought.
 
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