Systems and methods for electrical leakage detection

A method for detecting balanced electrical leakage between a power source and a frame ground of a machine, comprising:

• connecting a leakage detection resistor between a terminal of the power source and the frame ground;
• measuring a first voltage at a positive voltage side of the power source;
• measuring a second voltage at a negative voltage side of the power source;
• determining a first circuit unbalance based on the first and the second voltage measurements;
• determining a first leakage resistance between the terminal of the power source of the frame ground based on the first and second voltages and a resistance of the leakage detection resistor;
• connecting a first voltage divider between the positive voltage side of the power source and the ground;
• and
• connecting a second voltage divider between the negative voltage side of the power source and the ground. wherein the leakage resistance is evenly distributed between the first and the second voltage dividers.

A fault detection apparatus for a machine, comprising:

• a power source, electrically referenced to a machine frame;
• a leakage detection switch, connected to a ground;
• a leakage detection resistor, interposed between a power source terminal and the switch having a leakage detection resistance;
• a voltage measuring device that measures voltages of the power source at positive and negative voltage sides of the ground;
• a first and a second voltage divider, each comprises two resistors wherein a leakage resistance is evenly distributed between the first and the second voltage dividers;
• and
• a leakage calculator that calculates the leakage resistance and a leakage current of the machine based on the measured voltages at the positive and negative voltage sides, the leakage detection resistance, and a known power source impedance.