On-line detection of low-level arcing faults in metal-clad electrical apparatus

In history of metal-clad electrical apparatus, many equipment damages and burndown cases have been reported. The low-level electric arcing faults, ultimately causing high level arcs, lead to extreme pressure development in switchgear rooms causing severe explosions and burndowns. This paper discusses the development of a microprocessor based detection system, based on four different physical phenomena, for reliable and accurate detection of arcing faults in metal-clad electrical apparatus. Actual real-time arcing was generated on a dry type 15 kVA, 230/115V Y/Δ transformer enclosed in a 30“×30”×21” metallic enclosure. Some results showing the performance of the detection system are presented in the paper