A system and 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. The power source is used to apply a voltage to a device. The system may use a high impedance device coupled across a switch, with the switch being in communication with a portion of the device. A control system may monitor a voltage across the high impedance device and determine if the voltage across the high impedance device exceeds a predetermined threshold. Exceeding the predetermined threshold indicates that an unsafe voltage from the power source is present on the ground conductor. A natural high impedance path between the device and the Earth is used to provide an Earth connection through the device to the Earth during operation of the system.