An apparatus and methods are disclosed for monitoring the operation of an electrical power-transfer system and detecting and handling hazardous and undesirable system states. In accordance with one embodiment, an electrical signal is injected into the electrical power-transfer system. During or after the injection of the electrical signal, an electrical property between a first sensor and a second sensor are measured to obtain a measurement. The electrical power-transfer system is determined to be in a hazardous state based on the measurement, and in response to the determination one or more actions are performed to correct the hazardous state.