EGC size

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Rob if we look at it the way you want us too the section as currently written would never require us to increase the EGC. :smile:

That section was changed for the 2002 NEC and I think we all agree more thought should have been made about wording.

Perhaps someone here will put in a proposal for 2014? :smile:
 
iwire said:
Rob if we look at it the way you want us too the section as currently written would never require us to increase the EGC. :smile:

That section was changed for the 2002 NEC and I think we all agree more thought should have been made about wording.

Perhaps someone here will put in a proposal for 2014? :smile:
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I'm not disagreeing with you but we have to interpret using the actual words written in the code and IMO the words in the code support my argument. :grin:
 
infinity said:
But Dennis don't you find a contradiction in the two points that you've made in this post? First you're saying that the graphic does not show an increase in conductor size due to it's capacity but then you're saying that the OP does show an increase in conductor size so the #12 is no good. Actually the two examples are the same.
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I do see the contradiction. This is why this section is very poorly written. In the graphic case I can see why the wire size would be considered increased, however with the op I do not see it as the same scenario.

It appears we can interpret this section to suit our needs if we need to-- I am not saying you are doing that--it is just poorly written. Give the bad job I have to try and understand what the code panel is looking for here.

Unfortunately no matter what you or I decide there is the AHJ who will make this decision.

Let's look at your example again only this time with a pigtail of #6 for 12" to tie on to the #12 back to the panel. Have I increased the size of the ungrounded conductor? I could argue that you would need a #6 ground for 12" then tie it to the #12. At what point would it be considered increased.
 
I really don't know but...

I really don't know but...

Dennis Alwon said:
Okay, now that none of this is settled, can someone tell me why a 20 amp circuit with an ungrounded #6 wire needs a #6 EGC to trip the breaker. Why wouldn't a #12 EGC work or work as well as the #6 EGC?
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My best guess is that the instantaneous fault current needs a return path that is the equal of the path that is supplying the fault point so that the OCPD will trip as rapidly as possible. I could imagine an inadequate EGC allowing the fault current to continue long enough to cause damage or ignition of adjacent combustibles.
 
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