Current through September 30, 2024
Section 183.425 - Conductors: General(a) Each conductor must be insulated, stranded copper.(b) Except for intermittent surges each conductor must not carry a current greater than that specified in Table 5 for the conductor's gauge and temperature rating.(c) For conductors in engine spaces, amperages must be corrected by the appropriate correction factor in note 1 of Table 5.(d) Each conductor in a multiconductor sheath must be at least a No. 18 AWG conductor.(e) Each conductor installed separately must be at least a No. 16 AWG conductor.(f) Each No. 18 AWG conductor in a multiconductor sheath may not extend out of the sheath more than 30 inches.(g) This section does not apply to communications systems; electronic navigation equipment; electronic circuits having a current flow of less than one ampere; conductors which are totally inside an equipment housing; resistance conductors that control circuit amperage; high voltage secondary conductors and terminations that are in ignition systems; pigtails of less than seven inches of exposed length and cranking motor conductors. Table 5-Allowable Amperage of Conductors
Conductor size (AWG) | Temperature rating of conductor insulation |
60 °C (140 °F) | 75 °C (167 °F) | 80 °C (176 °F) | 90 °C (194 °F) | 105 °C (221 °F) | 125 °C (257 °F) | 200 °C (392 °F) |
18 | 10 | 10 | 15 | 20 | 20 | 25 | 25 |
16 | 15 | 15 | 20 | 25 | 25 | 30 | 35 |
14 | 20 | 20 | 25 | 30 | 35 | 40 | 45 |
12 | 25 | 25 | 35 | 40 | 45 | 50 | 55 |
10 | 40 | 40 | 50 | 55 | 60 | 70 | 70 |
8 | 55 | 65 | 70 | 70 | 80 | 90 | 100 |
6 | 80 | 95 | 100 | 100 | 120 | 125 | 135 |
4 | 105 | 125 | 130 | 135 | 160 | 170 | 180 |
3 | 120 | 145 | 150 | 155 | 180 | 195 | 210 |
2 | 140 | 170 | 175 | 180 | 210 | 225 | 240 |
1 | 165 | 195 | 210 | 210 | 245 | 265 | 280 |
0 | 195 | 230 | 245 | 245 | 285 | 305 | 325 |
00 | 225 | 265 | 285 | 285 | 330 | 355 | 370 |
000 | 260 | 310 | 330 | 330 | 385 | 410 | 430 |
0000 | 300 | 360 | 385 | 385 | 445 | 475 | 510 |
NOTES |
1. See the following table: | 60 °C | 75 °C | 80 °C | 90 °C | 105 °C | 125 °C | 200 °C |
| (140 °F) | (167 °F) | (176 °F) | (194 °F) | (221 °F) | (257 °F) | (392 °F) |
Temperature rating of conductor | 0.58 | 0.75 | 0.78 | 0.82 | 0.85 | 0.89 | 1.00 |
2. See the following table: | Correction | | | | | | |
| factor | | | | | | |
Number of current carrying conductors: | | | | | | | |
3 | 0.70 | | | | | | |
4 to 6 | .60 | | | | | | |
7 to 24 | .50 | | | | | | |
25 and above | .40 | | | | | | |
CGD 73-217, 42 FR 5944, Jan. 31, 1977; 42 FR 24739, May 16, 1977, as amended by CGD 81-092, 48 FR 55736, Dec. 15, 1983