Table 310.19 Allowable Ampacities of Single-Insulated Conductors, Rated 0 Through 2000 Volts, 150°C Through 250°C (302°F Through 482°F), in Free Air, Based on Ambient Air Temperature of 40°C (104°F)
| Temperature Rating of Conductor | |||||||
| Size AWG or kcmil | 150°C (302°F) | 200°C (392°F) | 250°C (482°F) | 150°C (302°F) | Size AWG or kcmil | ||
| Type Z | Types FEP, FEPB, PFA | Types PFAH, TFE | Type Z | ||||
| COPPER | NICKEL OR NICKEL-COATED COPPER | ALUMINUM OR COPPER-CLAD ALUMINUM | |||||
| 14 | 34 | 36 | 39 | – | 14 | ||
| 12 | 43 | 45 | 54 | 30 | 12 | ||
| 10 | 55 | 60 | 73 | 44 | 10 | ||
| 8 | 76 | 83 | 93 | 57 | 8 | ||
| 6 | 96 | 110 | 117 | 75 | 6 | ||
| 4 | 120 | 125 | 148 | 94 | 4 | ||
| 3 | 143 | 152 | 166 | 109 | 3 | ||
| 2 | 160 | 171 | 191 | 124 | 2 | ||
| 1 | 186 | 197 | 215 | 145 | 1 | ||
| 1/0 | 215 | 229 | 244 | 169 | 1/0 | ||
| 2/0 | 251 | 260 | 273 | 198 | 2/0 | ||
| 3/0 | 288 | 297 | 308 | 227 | 3/0 | ||
| 4/0 | 332 | 346 | 361 | 260 | 4/0 | ||
| CORRECTION FACTORS | |||||||
| Ambient Temp. (°C) | For ambient temperatures other than 40°C (104°F), multiply the allowable ampacities shown above by the appropriate factor shown below. | Ambient Temp. (°F) | |||||
| 41-50 | 0.95 | 0.97 | 0.98 | 0.95 | 105-122 | ||
| 51-60 | 0.90 | 0.94 | 0.95 | 0.90 | 123-140 | ||
| 61-70 | 0.85 | 0.90 | 0.93 | 0.85 | 141-158 | ||
| 71-80 | 0.80 | 0.87 | 0.90 | 0.80 | 159-176 | ||
| 81-90 | 0.74 | 0.83 | 0.87 | 0.74 | 177-194 | ||
| 91-100 | 0.67 | 0.79 | 0.85 | 0.67 | 195-212 | ||
| 101-120 | 0.52 | 0.71 | 0.79 | 0.52 | 213-248 | ||
| 121-140 | 0.30 | 0.61 | 0.72 | 0.30 | 249-284 | ||
| 141-160 | – | 0.50 | 0.65 | – | 285-320 | ||
| 161-180 | – | 0.35 | 0.58 | – | 321-356 | ||
| 181-200 | – | – | 0.49 | – | 357-392 | ||
| 201-225 | – | – | 0.35 | – | 393-43 | ||