Feasibility Study of a Differential Current Ground Fault or Leakage Current Sensor for Direct Current Offtrack Machines.

摘要

The results of a study and laboratory evaluation of a Hall-type device,as a sensor for monitoring low-level dc leakage currents in grounding conductors of off-track machines,are described. The report also contains schematic and logic diagrams for a dc ground fault interrupter system using a microprocessor and digital differentiating techniques to detect sudden changes in dc leakage of 15 milliampers or more,and appropriate logic to give warning signals or trip the load circuit-breaker when leakage becomes excessive.