(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 | | | | | | |
authority: 46 U.S.C. 4302; Pub. L. 103-206, 107 Stat. 2439; and Department of Homeland Security Delegation No. 0170.1, para. II, (92)(b). Subpart E is also authorized by Pub. L. 114-120, 130 Stat. 27
source: CGD 72-61R, 37 FR 15782, Aug. 4, 1972, unless otherwise noted.
cite as: 33 CFR 183.425