Table B.310.9 Ampacities of Three Triplexed Single Insulated Conductors, Rated 0 Through 2000 Volts, Directly Buried in Earth Based on Ambient Earth Temperature of 20°C (68°F), Arrangement per Figure B.310.2, 100 Percent Load Factor, Thermal Resistance (Rho) of 90
| Size AWG or (kcmil) | See Fig. B.310.2, Detail 7 | See Fig. B.310.2, Detail 8 | See Fig. B.310.2, Detail 7 | See Fig. B.310.2, Detail 8 | Size AWG or (kcmil) | ||||
| 60°C (140°F) |
75°C (167°F) |
60°C (140°F) |
75°C (167°F) |
60°C (140°F) |
75°C (167°F) |
60°C (140°F) |
75°C (167°F) |
||
| TYPES | TYPES | ||||||||
| UF | USE | UF | USE | UF | USE | UF | USE | ||
| COPPER | ALUMINUM OR COPPER-CLAD ALUMINUM | ||||||||
| 8 | 72 | 84 | 66 | 77 | 55 | 65 | 51 | 60 | 8 |
| 6 | 91 | 107 | 84 | 99 | 72 | 84 | 66 | 77 | 6 |
| 4 | 119 | 139 | 109 | 128 | 92 | 108 | 85 | 100 | 4 |
| 2 | 153 | 179 | 140 | 164 | 119 | 139 | 109 | 128 | 2 |
| 1 | 173 | 203 | 159 | 186 | 135 | 158 | 124 | 145 | 1 |
| 1/0 | 197 | 231 | 181 | 212 | 154 | 180 | 141 | 165 | 1/0 |
| 2/0 | 223 | 262 | 205 | 240 | 175 | 205 | 159 | 187 | 2/0 |
| 3/0 | 254 | 298 | 232 | 272 | 199 | 233 | 181 | 212 | 3/0 |
| 4/0 | 289 | 339 | 263 | 308 | 226 | 265 | 206 | 241 | 4/0 |
| 250 | – | 370 | – | 336 | – | 289 | – | 263 | 250 |
| 350 | – | 445 | – | 403 | – | 349 | – | 316 | 350 |
| 500 | – | 536 | – | 483 | – | 424 | – | 382 | 500 |
| 750 | – | 654 | – | 587 | – | 525 | – | 471 | 750 |
| 1000 | – | 744 | – | 665 | – | 608 | – | 544 | 1000 |
| Ambient Temp. (°C) |
Correction Factors | Ambient Temp. (°F) |
|||||||
| 6-10 | 1.12 | 1.09 | 1.12 | 1.09 | 1.12 | 1.09 | 1.12 | 1.09 | 43-50 |
| 11-15 | 1.06 | 1.04 | 1.06 | 1.04 | 1.06 | 1.04 | 1.06 | 1.04 | 52-59 |
| 16-20 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 61-68 |
| 21-25 | 0.94 | 0.95 | 0.94 | 0.95 | 0.94 | 0.95 | 0.94 | 0.95 | 70-77 |
| 26-30 | 0.87 | 0.90 | 0.87 | 0.90 | 0.87 | 0.90 | 0.87 | 0.90 | 79-86 |
Table B.310.10 Ampacities of Three Single Insulated Conductors, Rated 0 Through 2000 Volts, Directly Buried in Earth Based on Ambient Earth Temperature of 20°C (68°F), Arrangement per Figure B.310.2, 100 Percent Load Factor, Thermal Resistance (Rho) of 90
| Size AWG or (kcmil) | See Fig. B.310.2, Detail 9 | See Fig. B.310.2, Detail 10 | See Fig. B.310.2, Detail 9 | See Fig. B.310.2, Detail 10 | Size AWG or (kcmil) | ||||
| 60°C (140°F) | 75°C (167°F) | 60°C (140°F) | 75°C (167°F) | 60°C (140°F) | 75°C (167°F) | 60°C (140°F) | 75°C (167°F) | ||
| Types | Types | ||||||||
| UF | USE | UF | USE | UF | USE | UF | USE | ||
| COPPER | ALUMINUM OR COPPER-CLAD ALUMINUM | ||||||||
| 8 | 84 | 98 | 78 | 92 | 66 | 77 | 61 | 72 | 8 |
| 6 | 107 | 126 | 101 | 118 | 84 | 98 | 78 | 92 | 6 |
| 4 | 139 | 163 | 130 | 152 | 108 | 127 | 101 | 118 | 4 |
| 2 | 178 | 209 | 165 | 194 | 139 | 163 | 129 | 151 | 2 |
| 1 | 201 | 236 | 187 | 219 | 157 | 184 | 146 | 171 | 1 |
| 1/0 | 230 | 270 | 212 | 249 | 179 | 210 | 165 | 194 | 1/0 |
| 2/0 | 261 | 306 | 241 | 283 | 204 | 239 | 188 | 220 | 2/0 |
| 3/0 | 297 | 348 | 274 | 321 | 232 | 272 | 213 | 250 | 3/0 |
| 4/0 | 336 | 394 | 309 | 362 | 262 | 307 | 241 | 283 | 4/0 |
| 250 | – | 429 | – | 394 | – | 335 | – | 308 | 250 |
| 350 | – | 516 | – | 474 | – | 403 | – | 370 | 350 |
| 500 | – | 626 | – | 572 | – | 490 | – | 448 | 500 |
| 750 | – | 767 | – | 700 | – | 605 | – | 552 | 750 |
| 1000 | – | 887 | – | 808 | – | 706 | – | 642 | 1000 |
| 1250 | – | 979 | – | 891 | – | 787 | – | 716 | 1250 |
| 1500 | – | 1063 | – | 965 | – | 862 | – | 783 | 1500 |
| 1750 | – | 1133 | – | 1027 | – | 930 | – | 843 | 1750 |
| 2000 | – | 1195 | – | 1082 | – | 990 | – | 897 | 2000 |
| Ambient Temp. (°C) | Correction Factors | Ambient Temp. (°F) | |||||||
| 6-10 | 1.12 | 1.09 | 1.12 | 1.09 | 1.12 | 1.09 | 1.12 | 1.09 | 43-50 |
| 11-15 | 1.06 | 1.04 | 1.06 | 1.04 | 1.06 | 1.04 | 1.06 | 1.04 | 52-59 |
| 16-20 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 1.00 | 61-68 |
| 21-25 | 0.94 | 0.95 | 0.94 | 0.95 | 0.94 | 0.95 | 0.94 | 0.95 | 70-77 |
| 26-30 | 0.87 | 0.90 | 0.87 | 0.90 | 0.87 | 0.90 | 0.87 | 0.90 | 79-86 |