An induction motor system comprising an induction motor, equipped with a
heat recovery and water pumping apparatus and an apparatus for
controlling the electrical efficiency and resulting heat generation of
the induction motor. The motor is adapted to be coupled to an AC source
for supplying an AC signal. The controlling apparatus includes a
switching device, user controls and optional inputs. The switching device
is connected in series with the motor and is operative in either a high
impedance state wherein significant current flow through the motor is
prevented or a low impedance state wherein current flow through the motor
is substantially undisturbed. The user controls provide motor operational
input signals. The optional inputs provide setpoint and sensed water
temperature input signals. The controller means receives the motor
operational setpoint and sensed water temperature input signals from the
user controls and optional inputs, and switches the switching device
between its low and high impedance states in a predetermined sequence for
inducing a phase delay in the AC signal.