What is the minimum size EMT conduit required for three 14 AWG, six 12 AWG, and three 8 AWG conductors, all of which are THHN solid wires?

To determine the minimum size of EMT conduit required for three 14 AWG, six 12 AWG, and three 8 AWG conductors, you need to first calculate the total cross-sectional area of the wires and then consult the NEC (National Electrical Code) conduit fill requirements.

THHN wire has specific fill capacities based on gauge size. The NEC provides tables that outline the allowable fill percentages for conduits, which is crucial for ensuring safety and efficient operation.

For the wires in question:

• According to NEC, the total area for conductors must be calculated in square inches. The fill for each size of the wire is as follows:
  • 14 AWG THHN has an area of around 0.00175 square inches.
  • 12 AWG THHN has an area of about 0.0020 square inches.
  • 8 AWG THHN has an area of approximately 0.0030 square inches.

Calculating the total wire area:

• For three 14 AWG wires: 3 x 0.00175 = 0.00525 square inches
• For six 12 AWG wires: 6 x 0.002 = 0.012 square inches