General Catalogue - ed.60

CONDUCTOR RESISTENCE VALUES

The table shows the resistance values for the normalized sections of the European standard expressed in square millimeters (mm²) and normalized sections of the American standard expressed in AWG (American Wire Gauge) and MCM (short for thousands of circular mils or kcmil). NOTES The resistances of the European normalized sections are taken from the EN 60228 standard starting from 0.5 mm 2 , while the resistances of the American normalized sections are taken from the UL 1581 standard (Reference Standard for Electrical Wires, Cables, and Flexible Cords). In both cases, the resistances are for bare conductors at 20° C. The acronym ‘ns’ stands for ‘not specified’. The European and American standard have normalized sections, however there is no exact correspondence between the normalized sections of the two standards. This means that replacing a native mm 2 cable with a native AWG/MCM cable always involves oversizing or undersizing and vice versa. The replacement is therefore not an automatic operation but must be performed from time to time according to the application and project specifications. The conductor resistance value is a fundamental parameter for evaluating the different impact of the Joule effect as the conductor section changes.

Normalized section of the conductor

Exact conversion

Resistance

mm²

AWG

MCM

mm²

W/km

- - - - - - - - - - - - - - - - - - - - - - - - - - - - -

30 29 28 27 26 25 24 23 22 21 20 19 - 17 16 15 14 13 12 11 10 - - - - 18 -

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

0,0507 0.0647 0,0804 0,102 0,128 0,162 0,205 0,259 0,324 0,412 0,500 0,519 0,653 0,750 0,823

347 271 218 172 138 108 85,9 67,9 54,3 42,7 39,0 33,9 26,9 26,0 21,4 19,5 16,9 13,5 13,3 10,6 8,45 7,98 6,69 5,31 4,95 4,22

0,5

0,75

1,0

1,00 1,04 1,31 1,50 1,65 2,08 2,50 2,63 3,31 4,00 4,17 5,26 6,00 6,63 8,37 10,0 10,6 13,3 16,0 16,8 21,2 25,0 26,7 33,6 35,0 42,4 50,0 53,5 67,4 70,0 85,0 95,0 120 127 150 152 177 185 203 240 253 300 304 355 400 405 456 500 507 630 633 760 887 1010 107,2

1,5

2,5

4

3,343 3,300 2,652 2,102 1,910 1,667 1,323 1,210 1,049

6

-

9 8 7 6 5 4 3 2 - - -

10

16

0,8315 0,7800 0,6595 0,5231 0,5540 0,4146 0,3860 0,3287 0,2608 0,2720 0,2069 0,2060 0,1640 0,1610

25

35

-

-

1

50

-

- -

1/0 (0) 2/0 (00)

70

-

-

3/0 (000)

95

-

-

4/0 (0000)

120

- - - - - - - - - - - - - - - - - - - - - -

-

250

ns

150

-

0,1290

- -

300 350

ns ns

185

-

0,1060

-

400

ns

240

-

0,0801

-

500

ns

300

-

0,0641

- - - -

600 700 800 900 -

ns ns ns ns

400

0,0486

500

-

0,0384

-

1000

ns

630

-

0,0287

- - - -

1250 1500 1750 2000

ns ns ns ns

402