Ampacities of Insulated Conductors

Ampacities of Insulated Conductors
(From NEC Table 310-16)

Not More than Three Conductors in Raceway or Cable or Earth (Directly Buried)

SizeCopper ConductorsAluminum Conductors
Copper-Clad Conductors
60°C
(140°F)
75°C
(167°F)
90°C
(194°F)
60°C
(140°F)
75°C
(167°F)
90°C
(194°F)
Wire SizeTypesTypesTypesTypesTypesTypes
TW, UFRHW, THW, THWN, XHHW, USE, ZWTBS, SA, SIS, FEP, FEPB, RHH, THHN, THWN, XHHWTW, UFRHW, THHW, THW, THWN, XHHW, USETBS, SA, SIS, THHN, THHW, THW-2, THWN-2, RHH, RHW-2, USE-2, XHH, XHHW, XHHW-2, ZW-2
AWG or Kcmilmm2
180.8--14---
161.3--18---
1412.1202025---
1213.3252530201201251
1015.330354025301351
88.4405055304045
613.3556575405060
421.2708595556575
326.785100110657585
233.6951151307590100
142.411013015085100115
1/053.5125150170100120135
2/067.4145175195115135150
3/085.0165200225130155175
4/0107195230260150180205
250127215255290170205230
300152240285320190230255
350177260310350210250280
400203280335380225270305
500253320380430260310350
600304355420475285340385
700355385460520310375420
750380400475535320385435
800405410490555330395450
900456435520585355425480
1000507455545615375445500
1250633495590665405485545
1500760520625705435520585
1750887545650735455545615
20001013560665750470560630

1The load current rating and the overcurrent protection for conductor types shall not exceed 15 amperes for 14 AWG, 20 amperes for 12 AWG, and 30 amperes for 10 AWG aluminum and copper-clad aluminum after any correction factors for ambient temperature and number of conductors have been applied.


Correction Factors for Ambient Temperature Over30°C, 86° F
Ambient TemperatureFor Ambient Temperatures Over 30° C, 86° F, multiply the ampacities shown above by the appropriate factor show below:
21-25°C,
70-77°F
1.081.051.041.081.051.04
26-30°C,
78-86°F
1.001.001.001.001.001.00
31-35°C,
87-95°F
.91.94.96.91.94.96
36-40°C,
96-104°F
.82.88.91.82.88.91
41-45°C,
105-113°F
.71.82.87.71.82.87
46-50°C,
114-122°F
.58.75.82.58.75.82
51-55°C,
123-131°F
.41.67.76.41.67.76
56-60°C,
132-140°F
-.58.71-.58.71
61-70°C,
141-158°F
-.33.58-.33.58
71-80°C,
159-176°F
--.41--.41

3-Wire residential services, allowable ampacities
[From NEC Table 310-15(B)(6)]
Copper AWGAluminum AWGService Ampacity
42100
31110
21/0125
12/0150
1/03/0175
2/04/0200
3/0250 kcmil225
4/0300 kcmil250