3 ms·

The safety depends entirely on the voltage, no?

• lazide 4y ago
  Not really no - the term for if a wire will melt/catch fire is ampacity, which depends on amps. It’s very possible to vaporize a wire with just a few volts with enough amps! The safety issue with voltage is due to the need for thicker insulation to avoid shorts, but the difference for 5V vs 48v isn’t that much. It’s possible to carry a lot more power for the same amps (aka same wire ampacity) by upping the voltage, as Watts=amps*volts That is why interstate power transmission goes up to millions of volts. Most electrical codes also have carve outs for ‘low voltage’ as it’s tedious to try to regulate all the various ‘not dangerous’ stuff, which is considered 48 volts and below, which is why it’s limited to 48v. It’s considered ‘not dangerous’ due to the resistance/insulation of human skin making it a bit harder to kill your self with it, but with some work, still possible. It doesn’t take much amperage, if you’re trying - USB 2.0 has more than enough. AC needs thicker insulation vs DC, but that is due to the peak of the AC waveform being much higher than the nominal voltage. 170V for ‘120V’ AC, for instance.
• lmpdev 4y ago
  Cable fires are caused by the current flowing through a wire exceeding its current rating Voltage is largely irrelevant Have a look at the gauge of mains wires (~14-22 AWG) compared to what you'd put on a serious 12V-48V battery (2-8 AWG)