Ampacities of Insulated Conductors [NEC Table 310.15(B)(16)] Based on Ambient Temperature of 30°C (86°F). Rated Up to 2000V. Not more than 3 Conductors in Raceway, Cable or Earth (Directly Buried) | |||||||
Size | Copper Conductors | Aluminum or Copper-Clad Conductors | |||||
60°C 140°F | 75°C 167°F | 90°C 194°F | 60°C 140°F | 75°C 167°F | 90°C 194°F | ||
Wire Size | Types | Types | Types | Types | Types | Types | |
TW, UF | RHW, THHW, THW, THWN, XHHW, USE, ZW | TBS, SA, SIS, FEP, FEPB, MI, RHH, RHW-2, THHN, THHW, THW-2, THWN-2, USE-2, XHH, XHHW, XHHW-2, ZW-2 | TW, UF | RHW, THHW, THW, THWN, XHHW, USE, ZW | TBS, SA, SIS, FEP, FEPB, MI, RHH, RHW-2, THHN, THHW, THW-2, THWN-2, USE-2, XHH, XHHW, XHHW-2, ZW-2 | ||
AWG or kcmil | mm2 | ||||||
18 | 0.8 | - | - | 14 | - | - | - |
16 | 1.3 | - | - | 18 | - | - | - |
141 | 2.1 | 15 | 20 | 25 | - | - | - |
121 | 3.3 | 20 | 25 | 30 | 151 | 201 | 251 |
101 | 5.3 | 30 | 35 | 40 | 25 | 301 | 351 |
8 | 8.4 | 40 | 50 | 55 | 35 | 40 | 45 |
6 | 13.3 | 55 | 65 | 75 | 40 | 50 | 55 |
4 | 21.2 | 70 | 85 | 95 | 55 | 65 | 75 |
3 | 26.7 | 85 | 100 | 115 | 65 | 75 | 85 |
2 | 33.6 | 95 | 115 | 130 | 75 | 90 | 100 |
1 | 42.4 | 110 | 130 | 145 | 85 | 100 | 115 |
1/0 | 53.5 | 125 | 150 | 170 | 100 | 120 | 135 |
2/0 | 67.4 | 145 | 175 | 195 | 115 | 135 | 150 |
3/0 | 85.0 | 165 | 200 | 225 | 130 | 155 | 175 |
4/0 | 107 | 195 | 230 | 260 | 150 | 180 | 205 |
250 | 127 | 215 | 255 | 290 | 170 | 205 | 230 |
300 | 152 | 240 | 285 | 320 | 195 | 230 | 260 |
350 | 177 | 260 | 310 | 350 | 210 | 250 | 280 |
400 | 203 | 280 | 335 | 380 | 225 | 270 | 305 |
500 | 253 | 320 | 380 | 430 | 260 | 310 | 350 |
600 | 304 | 350 | 420 | 475 | 285 | 340 | 385 |
700 | 355 | 385 | 460 | 520 | 315 | 375 | 425 |
750 | 380 | 400 | 475 | 535 | 320 | 385 | 435 |
800 | 405 | 410 | 490 | 555 | 330 | 395 | 445 |
900 | 456 | 435 | 520 | 585 | 355 | 425 | 480 |
1000 | 507 | 455 | 545 | 615 | 375 | 445 | 500 |
1250 | 633 | 495 | 590 | 665 | 405 | 485 | 545 |
1500 | 760 | 525 | 625 | 705 | 435 | 520 | 585 |
1750 | 887 | 545 | 650 | 735 | 455 | 545 | 615 |
2000 | 1013 | 555 | 665 | 750 | 470 | 560 | 630 |
1 The load current rating and the overcurrent protection for conductor types shall not exceed 15A for 14 AWG, 20A for 12 AWG, and 30A for 10 AWG aluminum and copper-clad aluminum after any correction factors for ambient temperature and number of conductors have been applied. |
Correction Factors for Ambient Temperature over 30°C (86° F) [NEC Table 310.15(B)(2)(a)] | |||||||
Ambient Temperature | For Ambient Temperatures over 30°C (86°F), multiply the ampacities shown above by the factor show below: | ||||||
°C | °F | 60°C 140°F | 75°C 167°F | 90°C 194°F | |||
≤ 10 | ≤ 50 | 1.29 | 1.20 | 1.15 | |||
11-15 | 51-59 | 1.22 | 1.15 | 1.12 | |||
16-20 | 60-68 | 1.15 | 1.11 | 1.08 | |||
21-25 | 69-77 | 1.08 | 1.05 | 1.04 | |||
26-30 | 78-86 | 1.00 | 1.00 | 1.00 | |||
31-35 | 87-95 | .91 | .94 | .96 | |||
36-40 | 96-104 | .82 | .88 | .91 | |||
41-45 | 105-113 | .71 | .82 | .87 | |||
46-50 | 114-122 | .58 | .75 | .82 | |||
51-55 | 123-131 | .41 | .67 | .76 | |||
56-60 | 132-140 | - | .58 | .71 | |||
61-65 | 141-149 | - | .47 | .65 | |||
66-70 | 150-158 | - | .33 | .58 | |||
71-75 | 159-167 | - | - | .50 | |||
76-80 | 168-176 | - | - | .41 | |||
81-85 | 177-185 | - | - | .29 |
120/240V 3-Wire residential services [NEC Table 310.15 (B)(7)] | ||
Copper AWG | Aluminum AWG | Rating (amps) |
4 | 2 | 100 |
3 | 1 | 110 |
2 | 1/0 | 125 |
1 | 2/0 | 150 |
1/0 | 3/0 | 175 |
2/0 | 4/0 | 200 |
3/0 | 250 kcmil | 225 |
4/0 | 300 kcmil | 250 |
250 kcmil | 350 kcmil | 300 |
350 kcmil | 500 kcmil | 350 |
400 kcmil | 600 kcmil | 400 |