Abstract: An improved testing apparatus for an electric motor in which the motor windings are energized in a manner to produce low frequency oscillatory rotation of the motor armature. Under such conditions, motor loading is provided by the rotary inertia of the armature itself, eliminating the need for a separate loading device such as a dynamometer. As with conventional testing practice, the test controller records motor current, voltage and phase shift information to evaluate the electrical characteristics of the motor under test. The test apparatus is readily adapted to test different sizes and types of motors.