Box Fill Calculation 2008 NEC

[handy10]

This question deals with how to interpret Art. 314.16(B)(1). If a single unbroken wire passes through a box, the article says it has a count of one. If the wire has a long loop, the loop counts as two. In its simplest form, the question is if a wire with a long loop passes through a box is the total count two or is it three (one for the wire and two for the loop).

 

[Smart $]

Total count is two for the looped wire. IMO, the concept behind this is twofold: 1) It takes up more room in the box, and 2) the likelihood the loop is left there intentionally for a future splice or tap.

 

[chris kennedy]

. IMO, the concept behind this is twofold: 1) It takes up more room in the box, and 2) the likelihood the loop is left there intentionally for a future splice or tap.

I have to say I was pretty pleased about that change myself.

 

[infinity]

I have to say I was pretty pleased about that change myself.

I wasn't. You could have a 13" loop of a hot and a neutral that counts as four conductors. You can leave 2-13" conductors to connect to a device and it would only count as 2 conductors. Either way you need to fold in 13" of conductors. What did this accomplish?

 

[handy10]

Thank you for the replies. I agree that the purpose of the loop count is to give more room in the box. However, I also wonder with infinity why it is done that way. Any number of grounding conductors seem to be counted as one.

 

[Cavie]

Thank you for the replies. I agree that the purpose of the loop count is to give more room in the box. However, I also wonder with infinity why it is done that way. Any number of grounding conductors seem to be counted as one.

That will be the next change in lets say 10 years? NEC moves slow that way.

 

[LarryFine]

Any number of grounding conductors seem to be counted as one.

There's no real reason for them to count more. Think about it:

Yes, the EGC's take up space, but (hopefully! ) don't contribute to temperature rise.

There will be at least two conductors for every EGC, so the box will be bigger accordingly.