In this paper, a web-based online monitoring system of low voltage series arcing was designed. Furthermore, the line impedance was anayzed. The method of arc detection was done by peak thresholding and peak counting of the current signal that were previously processed by a digital high pass filter in LabViewprogram. The algorithm in detection system was designed to recognize three common cases in a circuit, namely normal condition, load switching condition, and series arcing condition. The LabViewprogram was employed to communicate with a MySQL database that was located on a webhost server in internet network by sending the arcing detection log. The results showed that the proposed system could distinguish the arcing condition from the other cases and send this information to the web. In addition, the line impedance affected the sensitivity of arcing detection system since it attenuated the arcing signal.