Hi Steve,
Actually, a PF of 1.00 using 2KIL is the most liberal, not consevative, of the PF values to use. The lower the PF factor, the more the voltage drop will rise and this could easily mandate a larger conductor size.
Using V = IR, R incumbases all factors contributing to the circuit resistance. One of the major factors is PF along with ambient temperature.
Check out IEEE Std 141 exact voltage drop formula or just download Volts from ECN's store to see how PF and ambient temperature affect voltage drop.
