"HeyBub" writes:

(Probably even longer ago and farther away) But can't a suitable capacitor
change the phase on a motor such that the reactive load is out of phase with
the resistive load thereby fooling a KWH meter into thinking the motor (say
on an AC unit) is all reactive and therefore not measured?

No. In theory, a pure capacitive load is all reactive, and the current
drawn by that load will not show up on a normal watt-hour meter - but
that current can't do any useful work either. It's just some
electrons that slosh back and forth between the capacitor and the
utility. Put a resistance or an inductance in the circuit and you can
extract useful work - but the current phase will shift back towards the
voltage phase, and the meter will measure the actual power being
delivered.

Most motors are inductive on their own, and by adding capacitors to them
you can correct the phase angle back towards zero degrees. This gives
the same power output with less current, which reduces losses in the
wiring, so it's an advantage in some circumstances. But it doesn't
reduce the power recorded by the meter. And if you add too much
capacitance, current starts leading voltage, making things worse rather
than better.

Dave