What is the acceptable radius of the inner edge of a 90° bend for Type MC cable with a smooth sheath that has an outside diameter of 3/4 inch?

The acceptable radius of the inner edge of a 90° bend for Type MC (Metal-Clad) cable is primarily determined by the manufacturer's specifications and applicable code requirements for safe installation practices. For Type MC cable with a smooth sheath, a commonly referenced standard is that the minimum bending radius should be no less than 8 times the outside diameter of the cable.

Given that the cable has an outside diameter of 3/4 inch, the bending radius can be calculated as follows:

• 3/4 inch multiplied by 8 equals 6 inches.

This means that to maintain performance and prevent damage to the insulation and conductors, the bend radius must exceed this minimum.

However, in contexts like this question, guidelines provided may suggest slightly larger radii for safety and longevity of the installation. The chosen answer, which is 10 inches, is higher than the minimum required and thus falls within acceptable installation standards. This ensures that the cable is not subjected to undue stress during installation or over time, which aligns with good practices in electrical wiring to maintain safety and performance.

This approach to determining the acceptable radius helps reinforce the understanding of code requirements designed to protect both the installation and the integrity of the cables used.