What is the maximum number of 10 AWG THWN conductors that can pass through a metal wireway that is 4 inches wide and deep?

To determine the maximum number of 10 AWG THWN conductors that can fit into a 4-inch wide and deep metal wireway, we refer to the National Electrical Code (NEC) guidelines on conductor fill in raceways.

For a wireway or raceway, the fill capacity depends on both the cross-sectional area of the wireway and the ampacity of the conductors, which is primarily influenced by factors such as insulation type and conductor size. The NEC provides tables that specify the maximum allowable conductor fill based on the raceway size.

In the context of a 4-inch by 4-inch wireway, the total fill calculation involves determining the cross-sectional area of the wireway and the individual cross-sectional area of each conductor. For 10 AWG THWN conductors, the area for each conductor is approximately 0.0024 square inches.

When calculating the total permissible number of conductors that can fit in a wireway, a common guideline is to use a factor that limits the number of conductors to a certain percentage of the wireway space to ensure adequate air circulation and to prevent overheating.

Through detailed calculations and the application of the NEC rules for a given wireway size, it is established that the maximum