You don't say what you're measuring with, but it sounds pretty likely that you are using an rms meter and are not accounting for the phase shift of an inductive load such as the motor. Voltage and current go out of phase and thus you cannot get accurate readings the way you're doing it. For another, you need to use only ONE reference point for ALL your readings. The way your'e doing it you don't have a valid reference for the measurements, making them oranges and apples. If phasors, VI lead/lag, eli the iceman, and all that are meaningful, that's what you've forgotten. If that's not meaningful, then you have a little homework to do yet.
HTH,
Pop
2.0 x 2 : =4V. I calculated the resistive loss in the extension cord to be : 8.84A x 4.0V = 35.36 watts : : Strangely, when I measure the voltage at the motor end and the source : end of the extension cord, the difference is only 1V. Taking power : readings at both ends, the difference is 37watts, which is consistent : with my previous math. If the power lost in the wiring is 37W and the : current is 8.84A, then the voltage drop should be around 4V, but : somehow, the voltage drop is only 1V and 3V is getting cancelled out. : The inconsistency does not happen with a resistive load. : : Explanation? :