Allowable Ampacities Insulated Conductors (In a Raceway)

Table 310-16 1996 N.E.C.


 60°C 75°C 90°C 60°C 75°C 90°C
AWG
THW

THW

TW THWN
TW THWN
MCM UF USE THHN UF USE THHN

COPPER
 ALUMINUM
18



14*





16



18*





14 20* 20* 25*





12 25* 25* 30* 20* 20* 25*
10 30* 35* 40* 25* 30* 35*
8 40 50 55 30 40 45
6 55 65 75 40 50 60
4 70 85 95 55 65 75
3 85 100 110 65 75 85
2 95 115 130 75 90 100
1 110 130 150 85 100 115
1/0 125 150 170 100 120 135
2/0 145 175 195 115 135 150
3/0 165 200 225 130 155 175
4/0 195 230 260 150 180 205
250 215 255 290 170 205 230
300 240 285 320 190 230 255
350 260 310 350 210 250 280
400 280 335 380 225 270 305
500 320 380 430 260 310 350
600 355 420 475 285 340 385
700 385 460 520 310 375 420
750 400 475 535 320 385 435

* Unless otherwise specifically permitted elsewhere in the National Electrical Code Book, the overcurrent protection for conductor types marked with an asterisk shall not exceed 15 amperes for No. 14, 20 amperes for No. 12 & 30 amperes for No. 10 copper; or 15 amperes for No. 12 & 25 amperes for No. 10 aluminum & copper-clad aluminum after any correction factors for ambient temperature & number of conductors has been applied.