Faulty Protective Earth Ground Circuit Detection System And Method

A system for detecting the presence of a voltage on a ground conductor which is coupled to a protective Earth (PE) terminal associated with an alternating current (AC) power source, where the AC power source is being used to apply a charging voltage to a switch system of a charger associated with an electric vehicle, the system including:

• a high impedance device coupled across a switch of the switch system, with the switch being in communication with a chassis of the vehicle;
• a control system for monitoring a voltage across the high impedance device and determining if the voltage across the high impedance device exceeds a predetermined threshold, thereby indicating that an unsafe voltage from the AC power source is present on the ground conductor;
• where a natural high impedance path between the Earth and the vehicle's chassis is used to provide an Earth connection through the vehicle's chassis during operation of the system;
• and
• wherein the control system controls opening and closing of the switch system in response to the sensed voltage across the high impedance device.

A method for detecting the presence of a voltage on a ground conductor which is coupled to a protective Earth (PE) terminal associated with a power source, where the power source is being used to apply a voltage to a device, the method including:

• using a natural high impedance path including at least one of capacitance and resistance, between the device and the Earth, to form a connection with the Earth;
• sensing a voltage across a high impedance device coupled across a switch while the switch is open, with the switch being in communication with the PE connection between the device and the Earth;
• and
• using a control system in communication with the high impedance device to determine when a voltage across the high impedance device indicates the presence of an unsafe voltage from the power source being present on the ground conductor.