DOC · ARTICLE
How Many 2 AWG THHN Fit in 1-1/4-Inch EMT?
5 conductors of 2 AWG THHN fit in 1-1/4-inch EMT at the NEC fill limit — 38.7% of the conduit's 1.496 in² interior.
·1 MIN READ·EDITORIAL
5 conductors of 2 AWG THHN fit in a 1-1/4-inch EMT at the NEC fill limit. Maximum fill is 38.7%, under the 40% allowed for three or more conductors per NEC Chapter 9, Table 1.
The math
| Variable | Value | Source |
|---|---|---|
| 2 AWG THHN area | 0.1158 in² | NEC Table 5 |
| 1-1/4" EMT interior | 1.496 in² | NEC Table 4 |
| 40% allowance | 0.5984 in² | NEC Table 1 |
| Max conductors | floor(0.5984 / 0.1158) = 5 | calc |
Practical configurations
- 100A residential service feeder: 2 hots + 1 neutral = 3 conductors → 23.2% fill ✓
- Two parallel 4/0 phases for 200A: Not applicable — 4/0 needs larger conduit
- Sub-panel feeder with 2 hots + 1 neutral + 1 EGC + 1 isolated ground: 5 conductors → at the limit ✓
Next size up
- 1-1/2 EMT fits 7 of 2 AWG THHN at 39.8% fill
- 2-inch EMT fits 11 at 37.9% fill
Ampacity
2 AWG copper THHN: 130A at 90°C, 115A at 75°C, 95A at 60°C terminals. Standard breaker sizes: 100A, 110A, 125A. With 4 CCCs derate by 0.80: 130 × 0.80 = 104A — sufficient for 100A.
For aluminum 2 AWG: 100A at 75°C — the typical sub-feeder. Aluminum area in Table 5 is the same as copper (insulation determines area, not metal). See copper vs aluminum conductor.
FIG. 99
FAQ
5 conductors of 2 AWG THHN fit in 1-1/4-inch EMT at the NEC 40% fill limit. Calculation: 5 × 0.1158 in² = 0.579 in², or 38.7% of EMT's 1.496 in² interior.
FIG. 98