How many #14 AWG wires can be used in a 4' X 1 1/2 round box?

To determine the correct number of #14 AWG wires that can be used in a 4" x 1 1/2" round box, you need to consider the box fill calculations according to the National Electrical Code (NEC). The box fill calculation takes into account the volume of the box and the number of conductors, as well as any device or fitting that is inside the box.

In a standard round box, the fill capacity is defined by its volume, and each standard wire size has a fill requirement. For instance, a #14 AWG wire typically takes up a certain volume that must be added to the total fill calculation.

For a 4" round box, the volume is adequate to accommodate a specific number of conductors. It is generally accepted that a 4" round box can safely hold around 8 #14 wires, as long as proper rules are followed regarding box fill and any additional items inside the box.

Therefore, the correct answer of 7 #14 AWG wires in this context aligns with the permissible rules for fill capacity. This ensures safe practices for electrical installations, promoting safety and preventing overheating due to excessive wire bundling.