Patent ID: 8560254

Claim:
A method for testing an electrical system that includes a high voltage (HV) energy storage system, HV contactors, one or more energy consuming components, one or more energy supplying components, an HV bus, and discharge circuitry adapted to discharge residual electrical energy retained in capacitive elements of the one or more energy consuming components and the one or more energy supplying components, the method comprising the steps of: receiving a signal from a component of the one or more energy consuming components and the one or more energy supplying components and that indicates that the component is to be activated; in response to receiving the signal, performing a first diagnostic test to test whether the HV contactors open and close by opening a positive contactor of the HV contactors and closing a negative contactor of the HV contactors and evaluating a bus voltage and by opening the negative contactor of the HV contactors and closing the positive contactor of the HV contactors and evaluating a bus voltage; in response to the first diagnostic test determining that the HV contactors open and close, performing a second diagnostic test to test whether the discharge circuitry discharges the residual electrical energy; and in response to the second diagnostic test determining that the discharge circuitry discharges the residual electrical energy, allowing the HV contactors to be closed to enable an exchange of energy between the HV energy storage system, the one or more energy consuming components, and the one or more energy supplying components.