What is the maximum number of 10 AWG THHN aluminum conductors allowed in a four-inch by 1.5-inch octagonal box as per Table 314.16(A)?

To determine the maximum number of 10 AWG THHN aluminum conductors allowed in a four-inch by 1.5-inch octagonal box, we refer to the National Electrical Code (NEC) Table 314.16(A), which provides the fill capacity for various box sizes based on the size and type of conductors.

For a standard four-inch octagonal box, the volume is 24 cubic inches. When calculating the fill for conductors, we look at the volume allowance per conductor size and material. According to the code, a 10 AWG conductor, whether copper or aluminum, typically requires 2 cubic inches of fill space.

Thus, for aluminum conductors, the calculation would be as follows:

1. Determine the total volume of the box: 24 cubic inches.

2. Calculate the fill for each conductor: 2 cubic inches for a 10 AWG conductor.

3. Divide the total volume of the box by the volume needed for each conductor:

[ \frac{24 \text{ cubic inches}}{2 \text{ cubic inches/conductor}} = 12 \text{ conductors} ]

However, there are adjustment factors that apply for conductors. For more than two conductors