DOC · ARTICLE
How Many 2/0 AWG THHN Fit in 2-Inch EMT?
6 conductors of 2/0 AWG THHN fit in 2-inch EMT at the NEC fill limit — 39.7% of the conduit's 3.356 in² interior.
·1 MIN READ·EDITORIAL
6 conductors of 2/0 AWG THHN fit in a 2-inch EMT at the NEC fill limit. Maximum fill is 39.7%, just under the 40% allowed for three or more conductors per NEC Chapter 9, Table 1.
The math
| Variable | Value | Source |
|---|---|---|
| 2/0 AWG THHN area | 0.2223 in² | NEC Table 5 |
| 2" EMT interior | 3.356 in² | NEC Table 4 |
| 40% allowance | 1.3424 in² | NEC Table 1 |
| Max conductors | floor(1.3424 / 0.2223) = 6 | calc |
Practical configurations
- 200A service feeder (copper): 2 hots + 1 neutral + 1 EGC = 4 conductors → 26.5% fill ✓
- Two parallel 100A feeds (2 sets of 1/0 each): typically uses 1/0 not 2/0
- 400A service via parallel 2/0: 2 sets × 3 = 6 conductors → 39.7% fill — at the limit
Next size up
- 2-1/2 EMT fits 10 of 2/0 THHN at 37.9% fill
- 3-inch EMT fits 15 at 35.4% fill
Ampacity
2/0 copper THHN: 195A at 90°C, 175A at 75°C, 145A at 60°C terminals. With 4 CCCs derate by 0.80: 195 × 0.80 = 156A. Sufficient for 150A protection, tight at 175A.
For full 175A protection, step to 3/0 (225A at 90°C × 0.80 = 180A).
FIG. 99
FAQ
6 conductors of 2/0 AWG THHN fit in 2-inch EMT at the NEC 40% fill limit. Calculation: 6 × 0.2223 in² = 1.3338 in², or 39.74% of EMT's 3.356 in² interior.
FIG. 98