Timeline for Why are AWG charts rated in amperes and not in watts?
Current License: CC BY-SA 4.0
8 events
| when toggle format | what | by | license | comment | |
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| Jan 30, 2023 at 21:47 | vote | accept | CommunityBot | ||
| Jan 30, 2023 at 22:05 | |||||
| Dec 5, 2020 at 18:44 | comment | added | user140351 | @JRE " I don't care how much power the cable dissipates" power load but your answer with the examle up is enough to me tnx. | |
| Dec 5, 2020 at 13:55 | comment | added | JRE | @autodidact: Amperes. All you really care about is "will this wire carry X amount of current?" The power can be calculated from the current and the wire resistance if you need it, but nobody is interested in the power. The usual question is "will this 18 AWG wire safely carry 20 amperes?" I don't care how much power the cable dissipates, only how much current I can push through it with out it catching fire. | |
| Dec 5, 2020 at 13:40 | comment | added | user140351 | @TomCarpenter we all agree with you but the point is does a awg chart has to be rated in amps or in watts? | |
| Dec 5, 2020 at 13:36 | comment | added | Tom Carpenter | @bobflux - "Wattage doesn't matter, since power is volts*amps, and volts don't heat wires, amps do." - erm, it is power dissipation, in watts, that causes heating - \$P=I^2R\$. This power is equivalent to \$P=IV_{drop}\$, where \$V_{drop}=I_{cable}R_{copper}\$ is the voltage drop along a length of cable caused by a current flowing through it. The voltage is irrelevant from a rating point of view as it can be directly calculated from the current rating which is specificed based on an allowed temperature rise (power dissipation) for a given resistance of cable, which is proportional to area. | |
| Dec 5, 2020 at 13:29 | comment | added | Tom Carpenter | @autodidact Voltage is a differential measurement, the reference point is important. It doesn't matter whether your supply voltage is 10V or 10kV relative to some other point (e.g. another cable), the voltage drop across the length of the cable will be the same as it's proportional to current (\$V_{drop} = I_{cable}R_{copper}\$), and not supply voltage. Where supply voltage matters is whether the insulation can withstand the voltage differential to another point (e.g. ground, adjacent contductor, air, etc.) without breaking down which is a seperate rating unrelated to AWG. | |
| Dec 5, 2020 at 13:23 | comment | added | user140351 | "Likewise an uninsulated wire, or a enameled wire, can withstand a higher temperature" so let say a enameled wire rated for 10 amps can handel 10 amps from 10volts up to 10kvolts? | |
| Dec 5, 2020 at 13:12 | history | answered | bobflux | CC BY-SA 4.0 |