What is the minimum depth of a handhole enclosure when installing a four-inch non-metallic conduit containing four 350kcmil THWN conductors?

To determine the minimum depth of a handhole enclosure for a four-inch non-metallic conduit containing four 350 kcmil THWN conductors, one must consider the National Electrical Code (NEC) guidelines that specify handhole dimensions based on the size and number of conductors.

For conductors of sizes and configurations specified (four 350 kcmil THWN conductors), the NEC provides clarity on the minimum depth required to ensure safe installation and maintenance. In this context, the minimum depth must accommodate not only the physical dimensions of the conductors but also provide adequate space for cable bends, future access, and ensure proper heat dissipation.

The correct answer indicates a depth of 8 inches, which reflects the NEC requirements for smaller conductor configurations, ensuring that there’s enough space for the conductors to be installed and maintained without cramping or damaging them. This depth allows room to effectively manage the conductors' bends and branches while adhering to safety and code compliance.

Had the handhole depth been greater, it would not have been necessary based on the dimensions needed for these specific conductors. Hence, the most fitting choice for this scenario is indeed the minimum depth of 8 inches, as it meets the code requirements for safe installation and