Box Fill Look Ups

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By far the easiest calculation for box fill is when the conductors are all the same size. There is a table in NEC 314 which gives the maximum number of conductors allowed in various size boxes.

If a box happens to have a device in it, then a deduction from this number is made. If there are grounding conductors present in the box, they only count as one no matter how many there are. Read through this article to refresh your memory on what constitutes a deduction from the number in the table.

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