What is the required EMT size for an installation involving four 12 AWG and four 10 AWG THHN copper conductors?

To determine the required size of Electrical Metallic Tubing (EMT) for the installation involving multiple conductors, it's crucial to apply the National Electrical Code (NEC) guidelines, particularly NEC Table 1 of Chapter 9, which outlines the allowable conductors in various raceway sizes.

In this scenario, there are four 12 AWG (American Wire Gauge) conductors and four 10 AWG conductors. First, we need to calculate the total volume of the conductors. The area of conductors must be summed up, which involves knowing the cross-sectional areas of each wire type:

• The cross-sectional area for 12 AWG THHN conductors is approximately 3.31 mm².

• The cross-sectional area for 10 AWG THHN conductors is approximately 5.26 mm².

Next, we find the total area by multiplying the number of conductors by their respective areas. It's necessary to total the areas for the four 12 AWG conductors and the four 10 AWG conductors, leading to an overall value that needs to fit within the allowable fill capacity of the EMT.

After calculating the combined area, we refer to NEC tables to find the EMT size that can accommodate this total