📊 Copper Wire Ampacity (90°C Column)

AWG/kcmilCopper (Amps)Aluminum (Amps)Diameter (mils)
142564
12302581
104035102
85540129
67050162
49570204
311085229
212595258
1145110289
1/0170135325
2/0195150365
3/0225175409
4/0260205460
250290230517
300320255564
350350280606
400380305649

⚠️ Important Notes

Temperature Ratings: These values are for 90°C (194°F) rated conductors. Always use the appropriate column based on wire insulation rating.

Ambient Temperature Correction: Values must be corrected for ambient temperatures above 30°C (86°F) per NEC Table 310.15(B)(1).

Conduit Fill: Ensure wire size accounts for the number of current-carrying conductors in the conduit.

Length Matters: Ampacity is the current-carrying capacity. Long runs may require larger wire to limit voltage drop.

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