Patent attributes
Techniques are provided for detecting a fault across a pair of lines. Pulse power is applied across the pair of lines. The pulse power comprises alternating pulse on-time intervals and pulse off-time intervals. During a pulse off-time interval, a resistor is connected across the pair of lines and then disconnected when a voltage across the pair of lines reaches a first droop percentage in a first period of time. After disconnecting the resistor, it is determined whether the voltage across the pair of lines droops at least a second droop percentage within a second period of time that begins after the first period of time. Occurrence of a line-to-line fault across the pair of lines is determined when the voltage across the pair of lines droops by at least the second droop percentage or more within the second period of time.