33 CFR § 183.425 - Conductors: General.

§ 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]

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