What is the minimum depth required for a pull box that accommodates four 4/0 AWG conductors and one 4 AWG grounding conductor?

The minimum depth for a pull box accommodating conductors, including multiple large gauge wires, is determined by the National Electrical Code (NEC) requirements. For four 4/0 AWG conductors along with a 4 AWG grounding conductor, it is crucial that the pull box has sufficient depth to prevent damage to the wires and to allow for effective pulling and splicing.

The NEC specifies that pull boxes need to be deep enough to provide adequate bend radius and to prevent excessive strain on the conductors. In this scenario, a depth of 4 inches is required to safely accommodate the specified wire gauges while providing enough space for safe handling and installation.

In contrast, possible lesser depths would fail to provide the necessary clearance and bend radius for the larger 4/0 conductors, potentially leading to insulation damage or difficulty in making connections. Therefore, 4 inches is the minimum recommended depth for this specific arrangement of conductors.