Patent ID: 8593150

Claim:
A motor drive for providing power to an electric motor having a motor housing connected to a ground, the motor drive comprising: an input for receiving a source of DC bus voltage on at least one positive and one negative bus conductor; a drive housing connected to the ground and in communication via a current pathway with the input; an inverter receiving at least one positive and one negative bus conductor to synthesize an AC waveform connectable at an output of the inverter to the electric motor for driving a same; a first and second current sensor communicating with the positive and negative bus conductors respectively to sense current therethrough; a fault detection circuit receiving current signals from the first and second current sensors to analyze the current signals and to provide an output distinguishing a location of a ground fault with respect to portions of the motor drive, the ground fault providing current flow through the current pathway from at least one of the bus conductors and the motor, the fault detection circuit further providing a notification to as user indicating the location of the ground fault.