How Many 2 AWG Wires Fit in RMC Conduit?

Complete NEC-compliant fill chart for 2 AWG THHN wires in Rigid Metal Conduit (RMC) conduit. Maximum wire counts for all standard conduit sizes.

Quick Answer

For 2 AWG THHN wires in RMC conduit at 40% fill (3+ wires):

  • • 1/2" RMC: 1 wires
  • • 3/4" RMC: 1 wires
  • • 1" RMC: 3 wires

2 AWG in RMC Conduit Fill Chart

Conduit Size Max Wires (40% Fill) Fill % Max Wires (Nipple 60%) Fill %
1/2" 1 37% 1 37%
3/4" 1 21% 2 42%
1" 3 39% 4 52%
1-1/4" 5 38% 7 53%
1-1/2" 7 39% 10 56%
2" 11 37% 17 58%
2-1/2" 20 39% 31 60%
3" 30 39% 46 60%
3-1/2" 40 40% 60 60%
4" 51 40% 77 60%

Understanding the Fill Chart

According to NEC (National Electrical Code) Chapter 9, Table 1, the maximum conduit fill percentage depends on the number of conductors:

  • 1 conductor: 53% fill maximum
  • 2 conductors: 31% fill maximum
  • 3 or more conductors: 40% fill maximum
  • Nipples (24" or less): 60% fill maximum

This chart shows the maximum number of 2 AWG THHN conductors that can fit in each RMC conduit size while maintaining NEC compliance.

Calculation Example

Question: How many 2 AWG THHN wires can fit in 3/4" RMC conduit?

Wire area: 0.1158 sq in per conductor

Conduit internal area: 0.549 sq in

Allowable fill (40%): 0.2196 sq in

Maximum wires: 0.2196 ÷ 0.1158 = 1 wires

Answer: You can fit up to 1 wires of 2 AWG THHN in 3/4" RMC conduit.

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