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 ...

To figure out how many wires you can put into the electrical box, first you need to count up all the components. Each item in an electrical box counts as a different number of wires. Each insulated ...