What is the minimum depth required for a hand hole enclosure containing four 350kcmil THWN conductors?

The minimum depth required for a hand hole enclosure containing four 350kcmil THWN conductors is determined based on the conduit fill and the conductors' physical dimensions. When dealing with conductors of this size, it's important to ensure that there is adequate space for both the physical routing of the conductors and for any future maintenance that may be required.

In this case, a depth of 8 inches sufficiently accommodates the necessary conductors while following the National Electrical Code (NEC) guidelines, which provide specifications for the sizing of enclosures based on the type and number of conductors. This depth allows for the proper bending radius of the conductors to prevent damage and ensures they can be safely installed and accessed.

Choosing a depth greater than 8 inches may not be necessary for just four 350kcmil conductors, while opting for a depth less than this could potentially lead to issues with installation and compliance with NEC regulations concerning conductor protection and accessibility.