Calculating Box Fill


Old 06-18-07, 06:20 PM
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Calculating Box Fill

Sorry if this is a dumb question; I am very new here.

When calculating the size of a junction box, does the length of wire(s) contained in the box not matter? I'm guessing that the 2 cu. in. around 14 wire gauge is just the spherical area/space around the wire? Thanks.
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Old 06-18-07, 06:22 PM
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The length of the wire is not relevant to the calculation.
Old 06-18-07, 06:29 PM
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So if the box (however unlikely) gets jammed full with extra length of conductor, why is the calculation even used?
Old 06-18-07, 07:03 PM
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although the code does not directly address the situation of overly lengthy wires in general an inspector can, and will, if he sees it, ding you on it if the box is crammed.

If I remember correctly, there is reference somewhere in the code as to conductors that are looped in a box though but I cannot confirm this at the moment.

Cramming defeats the reason to calculate box fill.

a terminated wire in a box is expected to be a minimum of 6 inches. Since most electricians tend not to make the tails much longer than this, it typically is of no consequence.
Old 06-19-07, 09:20 AM
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110.12 Mechanical Execution of Work. "Electrical equipment shall be installed in a neat and workmanlike manner."

The inspector can fail any sloppy work, including excessively long pigtails or crammed boxes, under this article.

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