Time Response Analysis for Residual Current Devices

ESPINOZA, CRISTIAN; VILLAVICENCIO, FRANCISCO; CUZCO, OMAR; AGUILAR, JOSE; AYALA, EDY; MORALES, JOHN

Conferencia; 2017 IEEE PES Innovative Smart Grid Technologies Conference - Latin America, ISGT Latin America 2017; 2017

IEEE

Residual Current Devices are protection elementsused in many countries for electric shock prevention. Thesedevices detect any differential current flowing from one live lineto earth and the mechanism trips opening the circuit avoiding anaccident on people. The residual current is standardized based onhuman tolerance, usually 30 mA. In order to analyze theeffectiveness of this protection for real scenarios, in this paper, anexperimental research was performed using an electrical humanbody model including capacitors and resistances. They wereapplied to the limbs and multiple resistive loads simulating houseappliances. Later, in order to generate a controlled leakagecurrent by short circuits, the model was connected to a variableresistive load. After analyzing multiple signals produced in alaboratory, the results showed that a traditional protection relaycan trip in average at 8.81 milliseconds almost three times fasterthan the specifications in the datasheet. Besides, this elementscorrectly operate for different signal produced by short circuits.