Detection of electric arc faults by Arc Fault Detection Devices

In the last 30 years, new electrical devices capable of detecting the electric arc have been introduced. In the 90s the Arc Fault Circuit Interrupters were used in USA but lately such devices are widely used in Europe. At the moment, almost all electrical equipment manufacturers make their own version of such devices, called Arc Fault Detection Devices. These devices identify the fault signature of the undesired electric arc, produced in different configurations in respect to the circuit charge, and disconnect the circuit from the power supply according to specific demands. This means studying the symmetry of the current signal in relation to the sine waveform. At the same time, these devices must identify and allow the operation under normal conditions of some industrial devices inside which an electric arc occurs, such as drilling machines, cutting machines, etc. and allow their normal working without disconnection.This work proposes the study of the electrical parameters produced as a result of the normal working of some equipment (drilling machines, milling cutter, electric disc cutter), respectively produced as a fault in series with the circuit load. In the first case the waveform of the electric current is symmetric in relation to both half-periods of the supply signal, and in the second case it is asymmetric in relation to them. In this case the disconnection time was studied. For the tests there were used four Arc Fault Detection Devices with a nominal current of 16 Amps providing B or C tripping characteristics from three different producers.