Abstract: A system for automatically monitoring the insulation leakage resistance of an electric motor for a short period prior to operation thereof having timing means for delaying application of the motor control voltage to the motor and for applying a high voltage direct current to the windings of the motor during such period. A sense resistor is connected between the motor frame and the high voltage supply ground, and the leakage current therethrough is monitored by a comparator. When the leakage current exceeds a preselected threshold, an alarm is initiated and operation of the motor is inhibited.