For a box with conduits G=2, H=2.5, J=1.5, K=2, L=1, M=1.5, N=2 (inches), what is the minimum left-to-right length (inches)?

For a box with conduits G=2, H=2.5, J=1.5, K=2, L=1, M=1.5, N=2 (inches), what is the minimum left-to-right length (inches)?

• A. 29 in.
• B. 20 in.
• C. 25 in.
• D. 25 1/2 in.

Answer: (B)

The main idea is that the minimum left-to-right length must be wide enough to fit every conduit along that axis plus the required clearances and the box walls. Here the conduits on the left contribute widths of 2, 2.5, 1.5, and 2 inches, which adds up to 8 inches. The conduits on the right contribute 1, 1.5, and 2 inches, totaling 4.5 inches. Together that’s 12.5 inches of conduit width that must fit between the box faces. The remaining width, 7.5 inches, comes from the spacing requirements between conduits and from the outer edges to the box faces as specified by the diagram. Add those clearances to the conduit widths and you get a total minimum left-to-right length of 20 inches. Any smaller width would crowd the conduits or violate the required spacing, so 20 inches is the smallest feasible dimension.

The main idea is that the minimum left-to-right length must be wide enough to fit every conduit along that axis plus the required clearances and the box walls. Here the conduits on the left contribute widths of 2, 2.5, 1.5, and 2 inches, which adds up to 8 inches. The conduits on the right contribute 1, 1.5, and 2 inches, totaling 4.5 inches. Together that’s 12.5 inches of conduit width that must fit between the box faces. The remaining width, 7.5 inches, comes from the spacing requirements between conduits and from the outer edges to the box faces as specified by the diagram. Add those clearances to the conduit widths and you get a total minimum left-to-right length of 20 inches. Any smaller width would crowd the conduits or violate the required spacing, so 20 inches is the smallest feasible dimension.