Which size Electrical Metallic Tubing is appropriate for containing a circular 6/3 NM Cable with a diameter of 0.672 inches?

To determine the appropriate size of Electrical Metallic Tubing (EMT) for housing a circular 6/3 NM Cable with a diameter of 0.672 inches, it's crucial to refer to the National Electrical Code (NEC) guidelines regarding conduit fill.

The NEC provides specific fill calculations that dictate the maximum number of conductors or the maximum size of cables that can be placed inside different sizes of raceways or conduits. For a single conductor, as is the case with the 6/3 NM cable, the fill must not exceed 40% of the conduit’s internal space.

When considering the internal diameter of EMT, it is common for a 1-inch EMT conduit to have an internal diameter close to 1.049 inches. Given that the cable’s diameter is 0.672 inches, it fits well within the 40% fill ratio guideline.

Calculating the fill, the area of the conductor can be estimated, and compared to the available area in the conduit. The 1-inch EMT provides sufficient space to accommodate the 0.672-inch diameter cable without exceeding the fill limit, which is essential for safe electrical installations.

Based on these considerations, the 1-inch EMT is deemed appropriate for containing a circular 6