Note: This article is based on the 2005 NEC. Box fill isn’t just the number of wires in the box — it's the total volume of the conductors, devices, and fittings in a box. Every outlet box has a ...

Number of Conductors Allowed in a Wiring Box Boxes of different shapes and sizes can safely accommodate a varying number of wires, depending on their size. The total volume of the box is the ...