Test procedures have been developed to measure the amplitudes of the motor torque pulsations of a single-phase motor at two times the motor line frequency. The test procedures presented in this paper do not require the use of a dynamometer. The motor was fixed to a torsionally flexible frame. A small centrifugal blower wheel attached to the motor shaft was used to apply a load to the motor. The amplitudes of the motor torque pulsations at specified motor speeds were obtained by first measuring the amplitudes of the torsional accelerations of the motor stator at specified motor speeds and the mass moment of inertia of the motor stator. These values were then substituted into an appropriate equation to calculate the corresponding amplitudes of the motor torque pulsations. For the results reported in this paper, the motor speed was varied by changing the amplitude of the line voltage to the motor. The amplitude of the line voltage to the motor was varied from 50% to 100% of the rated motor voltage. The motor was operated at its rated line frequency (50 Hz or 60 Hz).

Units: I-P