How Many 500 MCM Wires Fit in EMT Conduit?

Complete NEC-compliant fill chart for 500 MCM THHN wires in Electrical Metallic Tubing (EMT) conduit. Maximum wire counts for all standard conduit sizes.

Quick Answer

For 500 MCM THHN wires in EMT conduit at 40% fill (3+ wires):

  • • 1-1/2" EMT: 1 wires
  • • 2" EMT: 1 wires
  • • 2-1/2" EMT: 3 wires

500 MCM in EMT Conduit Fill Chart

Conduit Size Max Wires (40% Fill) Fill % Max Wires (Nipple 60%) Fill %
1-1/2" 1 35% 1 35%
2" 1 21% 2 42%
2-1/2" 3 36% 4 48%
3" 5 40% 7 56%
3-1/2" 6 37% 9 55%
4" 8 38% 12 58%

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 500 MCM THHN conductors that can fit in each EMT conduit size while maintaining NEC compliance.

Calculation Example

Question: How many 500 MCM THHN wires can fit in 2" EMT conduit?

Wire area: 0.7073 sq in per conductor

Conduit internal area: 3.356 sq in

Allowable fill (40%): 1.3424 sq in

Maximum wires: 1.3424 ÷ 0.7073 = 1 wires

Answer: You can fit up to 1 wires of 500 MCM THHN in 2" EMT conduit.

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