wire size

[drums613]

#12 copper is ratted for 20a or 2400w at 120v if i would run a 277v line at the same amperage it would come out to 5540w would i have to run a bigger conductor

 

[ryan_618]

Re: wire size

Conductor sizing is a function of amperage. If your load is x amount of watts, divide x by your voltage and make sure the ampacity of the conductor is not exceeded. Does this answer your question?

 

[charlie b]

Re: wire size

To be precise, the current limit on a conductor is based upon its cross-sectional area. That is because of two relationships: (1) The resistance of a wire is proportional to the length divided by the cross-sectional area, and (2) The heat generated within the conductor is equal to the square of the current times the resistance. A larger area gives a smaller resistance, and a lower amount of heat generated. When you put too much current through a wire, the heat generated becomes too high, and it threatens the integrity of the insulation system. The bottom line is that the ampacity limits exist to protect the insulation.

 

[tom baker]

Re: wire size

12 AWG THHN copper is rated at 30 amperes, not 20.It is restricted to 20 amperes for some installations.

 

[drums613]

Re: wire size

thanks for the answers