Hi Steve,
"I guess that depends on whether or not you start with kW or kVA when you assume PF=1!"
Power factor is a independant measure of the cosine of the phase angle offset. If you look at the power triangle, the bottom leg is real, true or working power(P) in units of watts, kW or HP. The hypotenuse (top line) is apparent power(Pa) in units of VA or kVA, the verticle leg is Imaginary or Reactive power in units of VAR or kVAR. Using a little trig will derive the angle of reactive power or theta. The cosine of this angle is the circuit's power factor.
"Ambient temperature will certainly have an impact on what the conductor temperature is, but in the end, it's only the conductor temperature that matters."
The conductor's temperature is the accumulation of conductor heat from it's resistance and ambient temperature.
As a brief note, I am the author of Volts. Since Volts' download is free for 10-days you can try this problem as well as other scenarios to view the results.
