Optical based Internal Arc Fault Control Devices (IACDs) play a crucial role in the detection speed of arc faults in low-voltage switchgear assemblies. They can utilize different types of sensors (point and line) and contain different types of output (semiconductor and relay). The configuration of an IACD will influence the total detection time of such a system. This article presents a comparison of the detection speed of commercially available optical based IACDs. It describes the method used to measure the speed of operation of IACDs using a flashlight that simulates the illuminance of an electrical arc. The results are presented and compared using box plots and Individual Moving Range (I-MR) charts. Box plots offer at glance comparison of influence of different test conditions on the speed of operation, and I-MR charts help to evaluate the measurement method. The measurements also indicate a dependence of the reaction times of the tested IACD on the energy of the flashlight. This information is useful in designing the proper placement of optical sensors and allows the selection of a system configuration that will ensure the fastest reaction time under given test conditions applicable to low-voltage switchgear assemblies.
Burzyński et al. (Mon,) studied this question.