Electric Distribution Line Ground Fault Prevention Systems Using Dual Parameter High Sensitivity Relay Device, Monitoring Small Current Reduction with Small Increase in Negative Sequence Current

In a system for preventing ground fault or other short circuit in electric distribution line system, caused by a break in a line, utilizing programmable relay protection in a plurality of relay devices programmed to monitor high sensitivity parameters, the improvement of refine protection, which includes: in MODULE A, a protection subsystem having sufficient hardware and software that is programmed to detect changes in negative sequence overcurrent and instantaneous undercurrent on a main distribution line as well as a single phase tap line, utilizing a timer delay to calculate the changes over small periods of time. Second and third embodiments include substituting negative sequence with zero sequence readings in MODULE B or combining both MODULES.