15A breaker to be used with #14 AWG copper; anyone have a link?
So the I-squared-T rating for this breaker is 8100 x 12/60 = 1620 amps-squared-seconds.
For one-half cycle at 60 Hz this should trip at 440A.
With a dead short at the end of 1/4 ohm worth of Romex the rms current for this half cycle would be 120/(1/4) = 480A.
If #14 AWG copper fuses at ~170A (in one second?) then its rating is about 30,000 (A^2)-sec. So the breaker interrupts the current before the wire gets anywhere near the melting point, maybe when the wire reaches 90°C or so. . .?
Last edited by Thatguy; 11-19-2008 at 02:34 PM.