fuses and wire size

[dennis]

Maybe someone can help me here. The following ad is for a fuse holder with #16AWG wiring, and a 30 amp fuse. According to charts I have seen, 30A fuses should be used with #10 wire. How can a 30amp fuse be safely used with #16?
https://www.amazon.com/ZOOKOTO-Inline-H ... B075YD7BKC

[SUKI]

Maybe someone can help me here. The following ad is for a fuse holder with #16AWG wiring, and a 30 amp fuse. According to charts I have seen, 30A fuses should be used with #10 wire. How can a 30amp fuse be safely used with #16?

Well it all comes down to voltage and wire resistance. Low voltage wiring can be smaller as there is less heating wattage wise due to less voltage drop across the wire. But at 120v instead 32v there is 3.75 times the heating at the same wire resistance; hence, you need a larger size for 120V. Wire resistance is also the reason you must use larger than 10 AWG on long runs like between my service and the shop that uses 140 foot 50 amp 240 vac feeder. I needed 4 AWG to reduce the overall voltage drop plus when using aluminum you always go one size larger too.

[dennis]

I was thinking in terms of current. 3000 watts at 120 volts draws 25 amps, whereas at 240 volts it draws 12.5 amps, therefore requiring smaller wire at the higher voltage????

[KE4AVB]

Yes you go down one or two gauges just depends how much heating you can get by with.

https://en.wikipedia.org/wiki/American_wire_gauge
but I would stick with the 60C range.