Reference · NEC 2023
Tables 8 & 9 — drop data
K-method: K = 12.9 Cu / 21.2 Al at 75°C, CM below. Advanced: R/X in Ω/1000ft, PVC 75°C. Steel conduit: R ×1.02, X ≈ ×1.7. Verify against your adopted NEC edition.
Copper — CM + Table 9 PVC
| Size | CM | R Ω/kft | X Ω/kft |
|---|---|---|---|
| #14 | 4,110 | 3.14 | 0.058 |
| #12 | 6,530 | 1.98 | 0.054 |
| #10 | 10,380 | 1.24 | 0.05 |
| #8 | 16,510 | 0.786 | 0.052 |
| #6 | 26,240 | 0.51 | 0.051 |
| #4 | 41,740 | 0.321 | 0.048 |
| #3 | 52,620 | 0.254 | 0.047 |
| #2 | 66,360 | 0.201 | 0.045 |
| #1 | 83,690 | 0.16 | 0.046 |
| #1/0 | 1,05,600 | 0.127 | 0.044 |
| #2/0 | 1,33,100 | 0.101 | 0.043 |
| #3/0 | 1,67,800 | 0.08 | 0.042 |
| #4/0 | 2,11,600 | 0.064 | 0.041 |
| 250 kcmil | 2,50,000 | 0.054 | 0.041 |
| 300 kcmil | 3,00,000 | 0.045 | 0.041 |
| 350 kcmil | 3,50,000 | 0.039 | 0.04 |
| 400 kcmil | 4,00,000 | 0.034 | 0.04 |
| 500 kcmil | 5,00,000 | 0.027 | 0.039 |
| 600 kcmil | 6,00,000 | 0.023 | 0.039 |
| 750 kcmil | 7,50,000 | 0.018 | 0.038 |
| 1000 kcmil | 10,00,000 | 0.014 | 0.037 |
Aluminum — CM + Table 9 PVC
| Size | CM | R Ω/kft | X Ω/kft |
|---|---|---|---|
| #12 | 6,530 | 3.18 | 0.054 |
| #10 | 10,380 | 2 | 0.05 |
| #8 | 16,510 | 1.27 | 0.052 |
| #6 | 26,240 | 0.819 | 0.051 |
| #4 | 41,740 | 0.516 | 0.048 |
| #2 | 66,360 | 0.323 | 0.045 |
| #1 | 83,690 | 0.256 | 0.046 |
| #1/0 | 1,05,600 | 0.204 | 0.044 |
| #2/0 | 1,33,100 | 0.162 | 0.043 |
| #3/0 | 1,67,800 | 0.129 | 0.042 |
| #4/0 | 2,11,600 | 0.102 | 0.041 |
| 250 kcmil | 2,50,000 | 0.087 | 0.041 |
| 350 kcmil | 3,50,000 | 0.062 | 0.04 |
| 500 kcmil | 5,00,000 | 0.043 | 0.039 |
| 750 kcmil | 7,50,000 | 0.029 | 0.038 |
| 1000 kcmil | 10,00,000 | 0.022 | 0.037 |