I have measured the DC resistance of a split-phase capacitor run induction motor's two windings. They are 53 and 35 ohms. The motor is impedance protected. Using the nameplate voltage and current, I have calculated the total impedance at 60 Hz to be 110 ohms. This total impedance is larger than the DC resistance, and so I have algebraically subtracted the resistance from the total impedance to get the inductive impedance, but I don't know if I did that step right:
I don't know if you can add a resistance and an inductive impedance arithmetically this way. I have seen things like
R1 at angle 0 degrees + X1 at angle 90 degrees = sqrt(R1^2 + X1^2)
I have invested hundreds of dollars into this motor/generator and while I would like to avoid a rewind, these high resistances make a rewind look inevitable. If I can get a good model, though, I may find a Q>1 for some capacitance, and that would indicate, I think, that self-excitation could commence.
What is not shown in MotorAnalyis.bmp is R1 in series with L1 and so X1, and R2 in series with L2 and so X2, and R1/L1/X1 in parallel with R2/L2/X2 and the capacitor C.
Yours,
Doug Goncz Replikon Research Falls Church, VA 22044-0394