Conduit fill rate

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bunuelbresson

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Detroit, MI
An electrical subcontractor told me that ground conductors shouldn't be counted when calculating the conduit fill rate. I am not convinced because this doesn't make sense to me.

What do you guys think?
 

Dennis Alwon

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I think the electrician is incorrect. You must count the equipment grounding conductor for fill but you don't count it when you are using the de-rating for current carrying conductor's
 

augie47

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In no way is this meant to be demeaning but the term "ground" can mean different things when you are in Code discussions. The NEC defines "ground" as "The Earth"
Most often "ground" conductors are either equipment grounding conductors that, as Dennis points out, are not counted in fill derating, but are counted in conduit fill.
"Ground" could also reference grounded conductors, often a neutral but not always a neutral and
those are counted in conduit fill calculations and may or may not be counted in derating dependent on a lot of particulars.
You might enjoy explaining that to your electrical subcontractor if he used the term "ground" :)
 

infinity

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It's called conduit fill, meaning that if it fills the conduit it counts. It doesn't matter if it's a CCC, non-CCC or EGC. The purpose of limiting conduit fill is to protect the conductors during installation.
 

MasterTheNEC

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An electrical subcontractor told me that ground conductors shouldn't be counted when calculating the conduit fill rate. I am not convinced because this doesn't make sense to me.

What do you guys think?
So does he not think the conductor takes up space in the raceway?...when doing fill you count every conductor that takes up space......

And I will always assume in that question that he is speaking about the EGC or Equipment Grounding Conductor.....but either way if it was the EGC, grounded conductors, neutral conductors, Hot Conductors....regardless they all take up space in the raceway so they have to be accounted for...your friend is incorrect.:thumbsdown:
 

GoldDigger

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So does he not think the conductor takes up space in the raceway?...when doing fill you count every conductor that takes up space......

And I will always assume in that question that he is speaking about the EGC or Equipment Grounding Conductor.....but either way if it was the EGC, grounded conductors, neutral conductors, Hot Conductors....regardless they all take up space in the raceway so they have to be accounted for...your friend is incorrect.:thumbsdown:
But, paradoxically, when you are looking at the fill in a device box you do not count EGCs. I do not understand why.
 

MasterTheNEC

CEO and President of Electrical Code Academy, Inc.
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But, paradoxically, when you are looking at the fill in a device box you do not count EGCs. I do not understand why.
No pulling...no possible jam factor to contend with...no potential for side wall issues and the like........would be my guess.....and well.....you at least have to count (1) volume allowance in a box...lol
 

jmellc

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Durham, NC
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Facility Maintenance Tech. Licensed Electrician
And dude.....I am in AR...you can't use big words like that down here...."paradoxically":angel:

Funny but you make a point too. The code has been needlessly cluttered with $10 words. "Neutral" is a simpler term than "grounded electrode conductor" and "ground" is much simpler than "grounding electrode conductor" or "electrode grounding conductor". I just keep in mind that "Ed is neutral", "Inga is not."
 

jmellc

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Durham, NC
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Facility Maintenance Tech. Licensed Electrician
He may also be thinking of box fill, where all grounds count as one conductor, except if IG conductors are present, they count as one too.
 

GoldDigger

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Funny but you make a point too. The code has been needlessly cluttered with $10 words. "Neutral" is a simpler term than "grounded electrode conductor" and "ground" is much simpler than "grounding electrode conductor" or "electrode grounding conductor". I just keep in mind that "Ed is neutral", "Inga is not."
An admirable goal.
But the grounded conductor is not always a neutral and vice-versa. The second is often not counted as a CCC, while the first is in a corner grounded delta.
And a Ground Electrode Conductor is not the same as either a grounded conductor an Equipment Grounding Conductor.
If you want short words you could call them A,B, C, and D conductors, but that would not clarify things at all. :)
 

jmellc

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Durham, NC
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Facility Maintenance Tech. Licensed Electrician
An admirable goal.
But the grounded conductor is not always a neutral and vice-versa. The second is often not counted as a CCC, while the first is in a corner grounded delta.
And a Ground Electrode Conductor is not the same as either a grounded conductor an Equipment Grounding Conductor.
If you want short words you could call them A,B, C, and D conductors, but that would not clarify things at all. :)

I have heard of corner grounded deltas but don't think I've ever seen one. I just think of reading most any article in the code book and it always refers to neutrals as grounded electrode conductors.
 

GoldDigger

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I have heard of corner grounded deltas but don't think I've ever seen one. I just think of reading most any article in the code book and it always refers to neutrals as grounded electrode conductors.
I think you will find that almost all true neutrals are also grounded conductors, since the code requires their grounding for most cases. But the word *electrode* has no place in your sentence.
That leads to confusion with the GEC or the EGC which are not current carrying conductors at all.
The code makes a very clear distinction between conductors which carry normal current and those which carry only fault current. But then that gets confused with the CCC count for ampacity adjustment. The neutral will generally still be a CCC, but it will not be *counted* as one for derating purposes.
 

ActionDave

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I think you will find that almost all true neutrals are also grounded conductors, since the code requires their grounding for most cases. But the word *electrode* has no place in your sentence.
That leads to confusion with the GEC or the EGC which are not current carrying conductors at all.
The code makes a very clear distinction between conductors which carry normal current and those which carry only fault current. But then that gets confused with the CCC count for ampacity adjustment. The neutral will generally still be a CCC, but it will not be *counted* as one for derating purposes.
Here is a good example where the right answer is the best answer....for me anyway .
 
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