What is the maximum number of 10 AWG THWN conductors permitted through a cross-section of 4-inch-wide by 4-inch-deep by 30-foot-long metal wireway?

To determine the maximum number of 10 AWG THWN conductors that can fit through a cross-section of a wireway, it's essential to refer to the National Electrical Code (NEC) guidelines on conductor fill. This code outlines the factors that affect the number of conductors allowed in a conduit or wireway, primarily considering the physical size of the conductors and the restrictions related to their installation.

In a metal wireway with a cross-section of 4 inches by 4 inches, the total area available for conductors is 16 square inches. The NEC specifies that conductors should not occupy more than a certain percentage of this area to ensure that the conductors can dissipate heat appropriately and to prevent overcrowding, which could lead to safety hazards.

For 10 AWG THWN conductors, the approximate area of each conductor is about 0.2 square inches. Therefore, we calculate the maximum number of conductors by dividing the total cross-sectional area of the wireway (16 square inches) by the area of one conductor (0.2 square inches):

16 square inches ÷ 0.2 square inches/conductor = 80 conductors.

However, due to the requirements of conductor fill adjustments and rounding considerations in