Power-factor correction

ELI5: that 0.86 power factor means the line carries extra current that does no useful work (it just sloshes back and forth magnetizing the motor). A capacitor bank supplies that reactive current locally, unloading the wiring upstream.

Real-world hook: factories add capacitor banks because utilities bill a penalty for poor power factor — correcting it pays for itself. (Try p_poles := 2 to re-derive a 3600 rpm machine.) Where next: Power Systems scales all this to kilovolts.