What is the maximum number of 10 AWG conductors that can be added to a junction box containing six 12 AWG wires with no additional devices?

To determine the maximum number of 10 AWG conductors that can be added to a junction box containing six 12 AWG wires, one must consider the fill capacity of the junction box, which is regulated by the National Electrical Code (NEC). The fill capacity is calculated based on the size and number of conductors present, as well as the box volume.

Each 12 AWG wire counts as two allowable wires for box fill calculations because of its size, so six 12 AWG wires would account for twelve fill units in total. The NEC specifies that each 10 AWG wire contributes a certain fill unit based on its size, which is less than that of 12 AWG cables, enabling more room for additional conductors.

Once the fill capacity is calculated with the existing six 12 AWG wires, the box's remaining capacity can be used to add the 10 AWG conductors. The number of allowed 10 AWG conductors will depend on the remaining fill after accounting for the existing conductors.

In this context, if the box can still accommodate four additional fill units after the existing wires are considered, it would allow for the addition of five 10 AWG conductors, matching the provided answer. This