Значение и использование

3.1 The selection criteria is to be applied for uses of (1) new cable and (2) replacement cable.

3.2 For the selection of new cable or the selection of replacement cable, this practice defines the choice criteria for conductor selection for cables in AWG (ASTM) or metric (IEC) sizes.

Область применения

1.1 This practice is intended as a guide to shipbuilders, shipowners, and design agents for use in the selection of conductor size for single conductor or multiple conductor cable sizes either in American Wire Gauge (AWG) or metric designations for commercial ship design and construction.

1.2 The comparison chart of electrical conductor sizes shown in Table 1 presents a combined listing of international standard sizes of Class 2 stranded copper conductors in accordance with AWG (Specification B8) English units or IEC (IEC 60228) metric units.

TABLE 1 Conversion Table—AWG/Metric Preferred Sizes of Conductors

Size
Metric,
mm ²

Size
AWG/MCM

Area in
Circ Mils
(Nominal)

Ampacity^A

dc Resistances at 20°C^B

Ohms
per 1000 ft

Ohms
per km

 

2000*^C

2 000 000

1155 

0.0053

0.0177

1000*

 

1 970 000

1145 

0.0054

0.0176

 

1750*

1 750 000

1070 

0.0063

0.0199

800*

 

1 580 000

1009 

0.0067

0.0224

 

1500*

1 500 000

980

0.0071

0.0232

 

1250*

1 250 000

890

0.0085

0.0278

630*

 

1 240 000

886

0.0096

0.0286

 

1000*

1 000 000

780

0.0106

0.0347

500*

 

987 000

772

0.0105

0.0369

400*

 

789 000

675

0.0133

0.0475

 

750*

750 000

655

0.0141

0.0463

 

600*

600 000

575

0.0176

0.0578

300*

 

592 000

570

0.0211

0.0607

 

500*

500 000

515

0.0211

0.0694

240*

 

474 000

499

0.0219

0.0762

 

400*

400 000

455

0.0264

0.0867

185*

 

365 000

431

0.0286

0.1000

 

350*

350 000

420

0.0302

0.0990

 

300*

300 000

375

0.0353

0.1157

150*

 

296 000

372

0.0353

0.1260

 

250*

250 000

340

0.0423

0.1388

120*

 

237 000

327

0.0436

0.1540

 

4/0*

211 600

300

0.0500

0.1639

95*

 

187 000

265

0.0551

0.1950

 

3/0*

167 000

260

0.0631

0.2065

70*

 

138 000

230

0.0752

0.2700

 

2/0*

133 100

225

0.0794

0.2605

 

1/0*

105 600

195

0.1002

0.3288

50*

 

98 700

185

0.1044

0.3910

 

1

83 690

165

0.1261

0.4139

35*

 

69 100

144

0.1495

0.5290

 

2*

66 360

140

0.1588

0.5211

 

3

52 620

120

0.2005

0.6577

25*

 

49 300

115

0.2057

0.7340

 

4*

41 740

105

0.2528

0.8295

16*

 

31 600

 89

0.3259

1.160

 

6*

26 240

 80

0.4023

1.320

10*

 

19 700

 63

0.5167

1.840

 

8*

16 510

 55

0.6380

2.093

6.0*

 

11 800

 43

0.8543

3.110

 

10*

10 380

 40

1.017

3.335

4.0*

 

7 890

 30

1.304

4.700

 

12*

6 530

 25

1.620

5.315

2.5*

 

4 930

 22

2.067

7.560

 

14*

4 110

 20

2.573

8.442

1.5*

 

2 960

. . .

3.417

12.20

 

16*

2 580

. . .

4.020

13.19

1.0*

 

1 970

. . .

5.213

18.20

0.90

 

1 773

. . .

6.45

21.10

 

18*

1 620

. . .

6.82

20.95

0.80

 

1 576

. . .

6.52

21.40

0.75*

 

1 480

. . .

6.82

24.80

0.60*

 

1 182

. . .

9.5

31.16

 

20*

1 020

. . .

10.5

34.45

0.50*

 

987

. . .

11.4

36.70

 

22*

640

. . .

16.9

55.44

0.20*

24*

404

. . .

26.7

87.60

 

26*

253

. . .

43.6

143.04

^A Ampacity of single-conductor cable in air at ambient temperature of 30°C and maximum conductor temperature not exceeding 60°C.^B Temperature correction: the conductor resistance may be corrected for moderate temperature differences from the noted reference temperature by the following equation. The parameter, αT, varies with conductivity and temperature. For a list of common temperature coefficients see Test Methods B193.

where: R_T   =   resistance at reference temperature T, R_t   =   resistance as measured at temperature t, α_T   =   known or given temperature coefficient of resistance of the conductor being measured at reference temperature T. At 20°C, the value is 0.003 93, T   =   reference temperature, and t   =   temperature at which measurement is made.

^C An asterisk (*) indicates preferred sizes for wires of American Wire Gauge or per IEC 60228 (metric) as appropriate.

1.3 As a precautionary caveat, some conductor sizes listed in Table 1 may exceed minimal size requirements of the U.S. Coast Guard, the American Bureau of Shipping, and IEEE STD 45 for specific applications.

1.4 The values stated for ampacity and dc resistance are presented as maximum values and are provided for information only.