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

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

   (Based on Ambient Temperature of 30° C, 86° F)

Size

Copper Conductors

Aluminum Conductors

Copper-Clad Conductors

60° C

75° C

90° C

60° C

75° C

90° C

(140° F)

(167° F)

(194° F)

(140° F)

(167° F)

(194° F)

AWG

Types

Types

Types

Types

Types

Types

Kcil

TW

RHW

TBS

TW

RHW

TBS

UF

THW

SA

UF

THHW

SA, SIS

THWN

SIS

THW

THHN, THHW

XHHW

FEP

THWN

THW-2

USE

FEPB

XHHW

THWN-2

ZW

RHH

USE

RHH, RHW-2

THHN

USE-2

THWN

XHH, XHHW

XHHW

XHHW-2, ZW-2

18

-

-

14

-

-

-

16

-

-

18

-

-

-

14 ¹

20

20

25

-

-

-

12 ¹

25

25

30

20 ¹

20 ¹

25 ¹

10 ¹

30

35

40

25

30 ¹

35 ¹

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

0

125

150

170

100

120

135

00

145

175

195

115

135

150

000

165

200

225

130

155

175

0000

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

800

410

490

555

330

395

450

900

435

520

585

355

425

480

1000

455

545

615

375

445

500

1250

495

590

665

405

485

545

1500

520

625

705

435

520

585

1750

545

650

735

455

545

615

2000

560

665

750

470

560

630

   Correction Factors for Ambient Temperature
Over 30° C, 86° F

Ambient Temperature

For Ambient Temperatures Over 30° C, 86° F, multiply the ampacities shown above by the appropriate factor show below:

21-25 C,

1.08

1.05

1.04

1.08

1.05

1.04

70-77 F

26-30 C,

1

1

1

1

1

1

78-86 F

31-35 C,

0.91

0.94

0.96

0.91

0.94

0.96

87-95 F

36-40 C,

0.82

0.88

0.91

0.82

0.88

0.91

96-104 F

41-45 C,

0.71

0.82

0.87

0.71

0.82

0.87

105-113 F

46-50 C,

0.58

0.75

0.82

0.58

0.75

0.82

114-122 F

51-55 C,

0.41

0.67

0.76

0.41

0.67

0.76

123-131 F

56-60 C,

-

0.58

0.71

-

0.58

0.71

132-140 F

61-70 C,

-

0.33

0.58

-

0.33

0.58

141-158 F

71-80 C,

-

-

0.41

-

-

0.41

159-176 F

¹ The 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.