Wire Size Chart

The following tables work well for PV applications.  We also have an inverter calculator which can help you decide what size wiring to use in a 12 volt system.

Wiring Reference Guide

Wiring Guide

Description

When additional wiring is needed refer to the following charts to determine correct sizing. Selecting the correct size and type of wire will enhance the performance and reliability of your PV system. The size of the wire must be large enough to carry the maximum current expected without undue voltage losses. All wire has a certain amount of resistance to the flow of current. This resistance causes a drop in the voltage from the source to the load. Voltage drops cause inefficiencies, especially in low voltage systems (12V or less). There are several different types of wire available depending on how and where it will be used. For example, there are wire types designed for resistance to sunlight exposure, high temperatures and direct burial. Specify wiring that will withstand the worst conditions.

The wire sizing guide below provides the minimum wire size needed to limit voltage drops to 5% at a given distance in a 12V or 24V system. If you want to limit your losses to 2% simply divide the distance by 2.5. For a 48V system multiply the distance taken from the 24V chart by 2. The dashes represent currents which cannot be handled by the wire size.

How charts work

1. On the left, locate the current you will be dealing with (either array or load current.) 2. Move across to locate distance to be traveled. 3. Move up to locate size of wire to be used.

Wire Sizing Chart 12 Volt System

Maximum one-way distance (feet) for 5% voltage loss in 12 volt systems. Wire Size (AWG)

WIRE GUAGE

Amps

14

12

10

8

6

4

2

1

0

00

000

0000

1

106

169

269

427

679

1080

1717

2166

2730

3444

4342

5475

2

53

85

134

214

340

540

859

1083

1365

1722

2171

2738

4

27

42

67

107

170

270

429

542

682

861

1086

1369

6

18

28

45

71

113

180

286

361

455

574

724

913

8

13

21

34

53

85

135

215

271

341

430

543

684

10

11

17

27

43

68

108

172

217

273

344

434

548

15

7

11

18

28

45

72

114

144

182

230

289

365

20

8

13

21

34

54

86

108

136

172

217

274

25

11

17

27

43

69

87

109

138

174

219

30

9

14

23

36

57

72

91

115

145

183

35

12

19

31

49

62

78

98

124

156

40

17

27

43

54

68

86

109

137

45

15

24

38

48

61

77

96

122

50

14

22

34

43

55

69

87

110

Wire Sizing Chart 24 Volt System

Maximum one-way distance (feet) for 5% voltage loss in 24 volt systems. Wire Size (AWG)

WIRE GUAGE

 AMPS

14

12

10

8

6

4

2

1

0

00

000

0000

1

213

338

537

854

1359

2160

3434

4332

5460

6887

8684

10951

2

106

169

269

427

679

1080

1717

2166

2730

3444

4342

5475

4

53

85

134

214

340

540

859

1083

1365

1722

2171

2738

6

35

56

90

142

226

360

572

722

910

1148

1447

1825

8

27

42

67

107

170

270

429

542

682

861

1086

1369

10

21

34

54

85

136

216

343

433

546

689

868

1095

15

14

23

36

57

91

144

229

289

364

459

579

730

20

17

27

43

68

108

172

217

273

344

434

548

25

21

34

54

86

137

173

218

275

347

438

30

18

28

45

72

114

144

182

230

289

365

35

24

39

62

98

124

156

197

248

313

40

34

54

86

108

136

172

217

274

45

30

48

76

96

121

153

193

243

50

27

43

69

87

109

138

174

219