If I may, a series cap actually produces a "phase shift" because the current leads the main current, rather than "lagging" it. Here's why:
If you picture a voltage sine wave across a load, the current is in phase with the voltage, because the current is at its peak during the voltage peak (during little change).
However, a capacitor in series with a load charges (and discharges) at the highest rate during the time the voltage sine wave is changineg (alternating from - to + and + to -).
Therefore, the current in a capacitive circuit peaks ahead of the voltage (sometimes by a full 90 deg.), and a two-phase magnetic field is "synthesized" by positioning the start-winding poles between the run-winding poles.
