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How much current can a copper conductor that is 2 meters long, 0.003m thick, and 0.00045m wide continuously carry? Also, the resistance is about 0.02 Ohms.

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  • \$\begingroup\$ google.com/search?q=ampacity+calculator \$\endgroup\$ – Ignacio Vazquez-Abrams Sep 16 '14 at 20:39
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    \$\begingroup\$ You might want to consider temperature as well... \$\endgroup\$ – copper.hat Sep 16 '14 at 20:46
  • \$\begingroup\$ It also depends on environment. In vacuum it will be lower than on diamond heatsink. \$\endgroup\$ – venny Sep 16 '14 at 20:56
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    \$\begingroup\$ @Andyaka It's DC, so at max how much power could it continuously deliver? Is 29V x 9A possible? Without fusing? I edited the voltage, should be 29V not 21V. \$\endgroup\$ – Pupil Sep 16 '14 at 21:44
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    \$\begingroup\$ The definitive answer would require finite element analysis. But comparing current density (here it is \$6.7\,\mathrm{A/mm^2}\$, cables for house wiring are about \$6.4\,\mathrm{A/mm^2}\$ with thick PVC sheath), it seems that it will probably work fine without much heating. \$\endgroup\$ – venny Sep 16 '14 at 23:09
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Assuming your conductor is flat, its cross-sectional area is 1.35mm. The resistivity of pure copper at 20°c is 1.72*10-8 Ohms/m. Resistance = resistivity x length / area, so your 2m length should measure about 0.026 Ohms.

The equivalent circular wire diameter is 1.31mm, which is slightly larger than 16AWG ( typically rated at 20A in a single core cable). At 9A it will drop about 0.23V and dissipate about 2W over its entire length.

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  • \$\begingroup\$ So what is the conclusion? Is 2W little or a lot? How hot will the wire get? \$\endgroup\$ – venny Sep 16 '14 at 23:03
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    \$\begingroup\$ 2W spread over a 2m length of wire? That's 10mW per cm. If it was a PCB trace then the temperature rise would be about 0.5°c. You would need a sensitive thermometer to measure it. \$\endgroup\$ – Bruce Abbott Sep 16 '14 at 23:52
  • \$\begingroup\$ Thanks Bruce, I assumed that the area is what I should've focused on to compare it to a round wire, because I know a conductor like that should easily manage 9A, and it seems it can and more, so 300W is not an issue for this conductor, 30Vx10A? \$\endgroup\$ – Pupil Sep 17 '14 at 0:03
  • \$\begingroup\$ Yes, or 600W = 60V at 10A etc. Only the current matters. Maximum voltage is determined by the insulation. \$\endgroup\$ – Bruce Abbott Sep 17 '14 at 0:25

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