Current Ratings for Continuous Service (IEC 60092-352)

Current Ratings for Continuous Service (IEC 60092-352)

Conductor 

temperature

90℃

Nominal cross- 

sectional Area 

(mm²)

Single core 

( A )

Two core 

( A )

Three core & four core 

( A )

0.5

10

8.5

7

0.75

13

11

9

1

18

15

13

1.5

23

20

16

2.5

30

26

21

4

40

34

28

6

52

44

36

10

72

61

50

16

96

82

67

25

127

108

89

35

157

133

110

50

196

167

137

70

242

206

169

95

293

249

205

120

339

288

237

150

389

331

273

185

444

377

311

240

522

444

366

300

601

511

420

 

d.c.

a.c.

d.c.

a.c.

d.c.

a.c.

400

690

670

587

570

483

469

500

780

720

663

612

546

504

500

890

780

757

663

623

546

Note

  1. Maximum permissible service temperature of the conductor is 90℃.
  2. The current ratings given above are based on an ambient air temperature of 45℃.
  3. The current ratings given above are for 6 cables of less bunched or laid together in flat formation. When more than 6 cables are bunched or laid close together, the current ratings

given above should be multiplied by correction factor 0.85.

  1. For cables with more than four core cables, the current ratings are calculated by the following formula.

I=I1/N1/3

I1: Current for single core cable

N: Number of cores

  1. Correction factors for various ambient air temperature

Maximum 

conductor temperature

Correction factors for ambient air temperature

35

40

45

50

55

60

65

70

75

80

90

1.10

1.05

1.00

0.94

0.88

0.82

0.74

0.67

0.58

0.47