Nec Cable Ampacity: copper
310.15B17#2/0 AWG to 310.15B17#400 kcmil
NEC (NFPA 70) cable ampacity ratings — allowable current for copper and aluminum conductors at 60/75/90°C insulation ratings in raceways and free air; high-temperature conductor ampacity at 150/200/250°C; ambient temperature correction factors; conductor fill adjustment factors
| conductor material | conductor size | ampacity 60C (A) | ampacity 75C (A) | ampacity 90C (A) | installation | nec table | standard |
|---|---|---|---|---|---|---|---|
| copper | 310.15B17#2/0 AWG | 225 | 265 | 300 | free air | 310.15(B)(17) | NEC (NFPA 70) 2017 Edition Table 310.15(B)(17) |
| copper | 310.15B17#2000 kcmil | 1,155 | 1,385 | 1,560 | free air | 310.15(B)(17) | NEC (NFPA 70) 2017 Edition Table 310.15(B)(17) |
| copper | 310.15B17#250 kcmil | 340 | 405 | 455 | free air | 310.15(B)(17) | NEC (NFPA 70) 2017 Edition Table 310.15(B)(17) |
| copper | 310.15B17#3 AWG | 120 | 145 | 165 | free air | 310.15(B)(17) | NEC (NFPA 70) 2017 Edition Table 310.15(B)(17) |
| copper | 310.15B17#3/0 AWG | 260 | 310 | 350 | free air | 310.15(B)(17) | NEC (NFPA 70) 2017 Edition Table 310.15(B)(17) |
| copper | 310.15B17#300 kcmil | 375 | 445 | 500 | free air | 310.15(B)(17) | NEC (NFPA 70) 2017 Edition Table 310.15(B)(17) |
| copper | 310.15B17#350 kcmil | 420 | 505 | 570 | free air | 310.15(B)(17) | NEC (NFPA 70) 2017 Edition Table 310.15(B)(17) |
| copper | 310.15B17#4 AWG | 105 | 125 | 140 | free air | 310.15(B)(17) | NEC (NFPA 70) 2017 Edition Table 310.15(B)(17) |
| copper | 310.15B17#4/0 AWG | 300 | 360 | 405 | free air | 310.15(B)(17) | NEC (NFPA 70) 2017 Edition Table 310.15(B)(17) |
| copper | 310.15B17#400 kcmil | 455 | 545 | 615 | free air | 310.15(B)(17) | NEC (NFPA 70) 2017 Edition Table 310.15(B)(17) |
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