Timeline for Maximum DC power available over specific distances from source
Current License: CC BY-SA 4.0
8 events
| when toggle format | what | by | license | comment | |
|---|---|---|---|---|---|
| Jun 11, 2022 at 14:12 | vote | accept | Brandon Kellett | ||
| Jun 11, 2022 at 14:12 | vote | accept | Brandon Kellett | ||
| Jun 11, 2022 at 14:12 | |||||
| Jun 11, 2022 at 14:02 | comment | added | Brandon Kellett | @Kubahasn'tforgottenMonica even with low currents with respect to the cable I should still unwind? Why would they heat up more than normal using typically acceptable current for a specific wire gauge. I'm not going to try push say 30A through a cable because I know that that would be pretty insane.. but what about 10A or so? | |
| Jun 10, 2022 at 18:38 | comment | added | Kuba hasn't forgotten Monica | @BrandonKellett You can test it using an \$ 8 \Omega \$ resistor, or a drum of cable. At timescales of seconds, both will be roughly equal. If you'll be testing using wire, you can use full current for a couple seconds, then wait 10 minutes for cooling. But you absolutely have to unwind the wire and lay it flat on the ground, so that it can properly cool. Otherwise, you'll have a melted slag of plastic on the drum, with copper embedded in it :) I've seen this happen when a wire test went astray: I got distracted and left for lunch. It was a $5k lunch in spite of much lower currents :/ | |
| Jun 10, 2022 at 11:33 | comment | added | Andy aka | The cable will have forward and return wires closely coupled thus, net-inductance might be of the order 250 nH per metre. 1 km might have an inductance of 250 uH but, there is the distributed capacitance of the cable which will keep back-emfs under control. You can always test the cable with no load except an oscilloscope; short out the cable momentarily and look at the back-emf on the scope @BrandonKellett | |
| Jun 10, 2022 at 11:23 | comment | added | Brandon Kellett | Side question - if I wanted to test this using a 1km drum of cable would there be any issues? I understand that heat may be an issue so would need to keep current low. But surely the big coil of wire would act as a massive inductor of sorts? So would need to ensure the load can be safely disconnected? | |
| Jun 10, 2022 at 10:52 | comment | added | Brandon Kellett | Thank you! Perhaps my search terms into google and other sites weren't along those lines so I missed this theorem. Anyways, good learning I guess... cheers! | |
| Jun 10, 2022 at 10:30 | history | answered | Andy aka | CC BY-SA 4.0 |